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BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10^ BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions lOji BMS3 Suitability of Fiber Insulating Lath as a Plaster Base 10^ BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls 10^ BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 100 BMS9 Structural Properties of the Insulated Steel Construction Company's "Frameless-Steel"

Constructions for Walls, Partitions, Floors, and Roofs lOji BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 100 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 150 BMS13 Properties of Some Fiber Building Boards of Current Manufacture 100 BMS14 Indentation and Recovery of Low-Cost Floor Coverings 100 BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

the Wheeling Corrugating Co 100 BMS16 Structural Properties of a "TUecrete" Floor Construction Sponsored by Tilecrete Floors, Inc 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 Supplement to BMS17, Soimd Insulation of WaU and Floor Constructions 50 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMS19 Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

Connecticut Pre-Cast Buildings Corporation 100 BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association 10^ BMS22 Structural Properties of "Dun-Ti-Stone" Wall Construction Sponsored by the W. E. Dunn Manufacturing Co 10^ BMS23 Structural Properties of a Brick Cavity-Wall Construction Sponsored by the Brick

Manufacturers Association of New York, Inc 100 BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWall Construction Sponsored by the Structural Clay Products Institute 100 BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 150 BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" Wall Construction

Sponsored by the Nelson Cement Stone Co., Inc 10^ BMS27 Structural Properties of "Bender Steel Home" WaU Construction Sponsored by the Bender Body Co 100 BMS28 Backflow Prevention in Over-Rim Water Supplies 100 BMS29 Survey of Roofing Materials in the Northeastern States 100 BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association 100 BMS31 Structural Properties of "Insulite" WaU and "Insulite" Partition Constructions Sponsored by The Insulite Co 150 BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association. 100

[List continued on cover page in]
UNITED STATES DEPARTMENT OF COMMERCE • Jesse H. Jones, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, Director BUILDING MATERIALS

and STRUCTURES

REPORT BMS95

Tests of Cement-Water Paints and Other Waterproofings

for Unit-Masonry Walls

by

CYRUS C. FISHBURN and DOUGLAS E. PARSONS

ISSUED MARCH 15, 1943

The National Bureau of Standards is a fact-finding organization;

it does not "approve" any particular material or method ot construction. The technical findings in this series of reports are to be construed accordingly.

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I943

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE I5 CENTS

i
Foreword

An extensive investigation of the water permeability of over 400 small masonrywall specimens has been conchided. The walls were tested, under conditions simulating

exposure to wind-driven rain, both before and after they were subjected to artificial or outdoor weathering. Some phases of the investigation are described in BMS Reports

7, 41, 55, 76, 82, and 94. Data on the permeability of walls built of masonry units are contained in BMS Reports 7 and 82, the latter report containing information complementary to that published in BMS7. The effects of heating and cooling and of wetting

and drying masonry walls, including stucco-faced walls, are described in BMS Reports

41 and 55, respectively. The effects of outdoor weathering on the permeability of masonry walls, not waterproofed, and on the durability of some waterproofings are discussed in BMS76. The permeability and weathering resistance of stucco- and

gunite-faced walls are reported in BMS94 (which also contains complementary information from BMS Reports 7 and 76).

This report, the final one on the investigation, describes the effectiveness and durability of cement-water paints and of other waterproofings for unit-masonry walls, and

it includes complementary information on subjects discussed in BMS Reports 7 and 76.

Lyman J. Briggs, Director.

[II]
Tests of Cement-Water Paints and Other Waterproofings for

Unit-Masonry Walls

by CYRUS c. FisHBURN and Douglas e. parsons

CONTENTS

Page

Foreword "

I. Introduction 2

II. Scope 2

III. Sponsors 2 IV. Wall specimens 3

1. Masonry materials 3

(a) Bricks 3

(b) Concrete units 3

(c) Mortars 3

2. Description and construction of the

walls 4

3. Designation of the walls and waterproofings 4

V. Method of testing . 4

1. Water-permeability test 4

(a) Apparatus and test method.. 4

(b) Observations 5

(c) Rating of performance 5

2. Outdoor exposure 5 VI. Cement-water paints 6

1. Materials and consistency 6

2. Method of application and curing„ _ 7

(a) Preparation of the walls for painting 7

(b) Kinds of brushes 8

(c") Application of the paints 9

(d) Curing of the coatings 10

(e) Condition of the cured paint

coatings 11

3. Some factors affecting the permeability of the cement-water

paint coatings II

(a) Kind of brush 15

(b) Kind of backing and its moisture content 15

(c) Paint consistency 15

(d) Curing conditions 16

(e) Kind of paint and of admixtures 16

(f) Use of a grout coat 17

4. Effect of weathering exposure on

permeability 17

5. Discussion 18 VII. Proprietary waterproofings applied to the exposed faces of the walls 19

1. Pigmented surface coatings 19

(a) Aquaplex 19

(b) Dricoat 20

(c) Drye 20

(d) Maure Brush-Tex and Plaster Special 20

Page VII. Proprietary waterproofings applied to the exposed faces of the walls—Continued

1. Pigmented surface coatings—con.

(e) Tymstone 21

(f) Varcraft 21

(g) Discussion 22

2. Colorless surface coatings 22

(a) Ampruf ._ 23

(b) Ceremul-W 23

(c) Filporize 23

(d) Maure liquid waterproofing. _ 24

(e) Por-fil-ite 24

(f) Sur-Ten-R 24

(g) Discussion 25

VIII. Larson Pre-Formed Waterproofing Units. 25

1. Construction of the .specimens 25

2. Effectiveness and durability 26 IX. Waterproofing applied to the unexposed

faces of the walls 29

1. Bituminous coatings 29

(a) Asphalt 30

(b) Coal tar . 31

(c) Asphalt roof coating 31

(d) Asphalt emulsion 31

(e) Bituminous plastic cement 31

(f) Discussion 32

2. Coatings of cementitious or of proprietary materials 33

(a) Portland-cement and sand

brush coating 33

(b) Iron-dust (iron powder and

sal ammoniac) brush coat- ing 33

(c) Portland-cement and iron- dust brush coatings 34

(d) Portland-cement, iron-dust,

and sand trowel coatings. _ 34

(e) Mortar parging 34

(f) Armor coat 35

(g) Dricoat 35

(h) Discussion 35 X. Conclusions 36

1. Cement-water paints 36

2. Emulsified resin and oil-base paints. 36

3. Colorless surface waterproofings 36

4. Joint treatments 36

5. Membrane waterproofing 37

6. Waterproofings on the inside (unexposed) faces of the walls 37

[1]
ABSTRACT

One hundred thirty-one small highly permeable

masonry wall specimens built of concrete blocks or of bricks were treated with cement-water paints or with

other waterproofings. The effectiveness of the treat- ments was measured by comparing the permeability

of the walls, before and after treatment, when they were

subjected to conditions simulating wind-driven rain. The durability of some treatments was observed by

again testing the specimens after they had been weathered outdoors. The cement-water paints were effective waterproofings and could be applied to the best advantage on the

walls of concrete blocks with stiff, rather than soft, brushes. The admixture of fine sand to the paint for the first coat applied to the coarse-textured concrete block increased the effectiveness and durability of the

paints. Thick paint films resulting from the application

of excessive amounts of paint were effective when

first applied, but they were much less durable than

thinner coatings. The permeability of the paint films

of average thickness was lower after weathering than

before. The colorless waterproofings were generally ineffective. Only one of the colorless waterproofings was satis- factory when first applied, but it was not durable and

was much more permeable than the best cement-water

paint treatments. The data confirm results previously

obtained, which indicate that the only effective and

durable method of waterproofing brick walls without

changing their appearance was by repointing or grouting

of the face joints.

A series of built-in waterproof membranes was an

effective waterproofing for brick walls if the leakage

through the facing was drained out of the wall through

weep holes at the bottom.

The bituminous coatings applied to the inside faces

of the walls were ineffective as waterproofings.

I. INTRODUCTION

The effectiveness and durabihty of waterproofings apphed to small walls built of masonry

units are also discussed in previous publications' of the National Bureau of Standards.

Although some of the walls described in those

papers were given surface treatments, applied

to the exposed faces, most of the tests were made on walls that were not waterproofed.

This paper describes the effectiveness and

dm-abdity of the cement-water paints and of other waterproofings applied to a second

group of waU specimens. The complemen1 Building Materials and Structures Reports BMS7, Water Permeability of Masonry Walls, and BMS76, Effect of Outdoor Exposure on the Water Permeability of Masom'y Walls.

tary data published in BMS7 and BMS76

are discussed briefly in this paper, which therefore contains practically all the information on

waterproofing that was obtained from the tests on both groups of walls.

II. SCOPE

Forty-five different waterproofings were

tested. The treatments of the exposed faces of

the walls included 9 pigmented and 6 colorless pi'oprietary materials and 16 laboratory-prepared cement-water paints. The waterproofings applied to the back (unexposed) faces of

the walls were five bituminous treatments, two

pigmented proprietary materials, and six ce- mentitious coatings prepared with or without

the addition of powdered iron and sal ammoniac.

One built-in bituminous membrane waterproofing was also tested. The number of proprietary

waterproofings tested was limited by the scope

of the investigation and was relatively very

small in comparison with the considerable number in use. The effectiveness of the surface waterproofings was determined from permeability tests made on the walls before and after treatment,

and the durability of some of them was observed

by additional permeability tests made after the

walls had been stored outdoors. The effective- ness of a built-in membrane waterproofing was

measured by comparing the performances of

walls with and without the membrane.

III. SPONSORS

The construction and waterproofing of most

of the walls were sponsored by the Government

agencies that collaborated with the Bureau in

the investigation. Some proprietary waterproofings were sponsored by the makers, who

fiirnished the materials and labor for the walls

and supervised the application of the waterpioofings to the specimens. These sponsors were

:

Armor Laboratories, Inc., Los Angeles, Calif.

;

sponsors of "Armor Coat."

Brisk Waterproofing Co. Inc., New York,

N. Y. ; sponsors of Larson "Pre-formed Waterproofing Units."

Maure Corporation, New York, N. Y.

;

sponsors of Maure "Brush-Tex", "Liquid

Waterproofing", and "Plaster Special."

[2]
Pal-Verd, Inc., Chicago, 111.; sponsors of "Sur-Ten R."

Tymstone Studio, Chicago, 111.; sponsors of

"Tymstone."

All the tests were made by the Bureau.

IV. WALL SPECIMENS

1. Masonry A-Iaterials

(a) Bricks

The dimensions and physical properties of the bricks are given in table 1 ; their general

characteristics are listed below.

Brick c, a dry-pressed, Irighly absorptive unit

with a high rate of absorption.

Brick b, a side-cut, shale unit.

Brick r, an end-cut, shale unit of special

shape containing five horizontal cored holes

and known as Mmilock brick.

Brick s, a stiff-mud, moulded brick.

Brick t, a side-cut, sm-face clay brick containing.' three l-in. cored holes.

{b) Concrete Units

The dimensions and physical properties of

the hollow concrete units are given in table 2;

their general characteristics arc listed below.

Block m, a two-cell, end-bearing, stone-conci'ete unit.

Block n, a cinder-concrete unit similar in

size and shape to block m. Blocks m and n

were purchased under Feck-ral Specification

SS-C-621, type 1, load bearing.

Block p, a two-cell, cinder-concrete bonding

unit.

A second shipment of blocks m and n were

received from the same manufacturer and used

in the construction of additional walls. The

units in the second shipment dift'ered from those

in the first in that they had thinner shells and

were stronger; the stone-concrete blocks were

less absorptive; the cinder-concrete blocks had

a smoother sm-face texture.

(c) Mortars

' The Munlock brick are illustrated in figures 2 and 3 of Building

Materials and Structures Report BMS82, Water Permeability of Walls

Built of Masoni'y Units.

The proportions and water retentivities of the mortars are given in table 3. The materials were proportioned by weight and mixed

in a small batch mixer. The amomits of water were adjusted to the satisfaction of the mason.

Table 1.

Physical properties of the bricks

Designation

Average dimensions Average dry

weight

Absorption by weight during total immersion Saturation

coeffi- cient, C/B

Absorption

tion by

partial immersion,

flat, 1 min. »

Time required for total penetration by capil- lary action Modulus of rupture

Compressive strength Thickness Width Length 5-hr cold

24-hr

cold, C

5-hr

boil, B

Flat Edge End

b

c_ _ r

in.3.6 3.9 8.0

3.8

3.8

in.7.8

8.1

2. 2 8.4

8.3

in.

2. 2 2.3

b 7. 9 2.3 2.2

lb

4. 4

5. 0

9. 5 5.3

4. 9

%

7. 7

14. 2

1. 5

11. 5

5. 7

%

8.3

14.6

1.6

12.3 6.0

%

11.4

16.9

1.9

.14. 5

9.

1

0. 73

.86

.84

.85

.66

9 37 112

3 66

37

hr

0. 4

. 1 1.4

.3.2

hr1.9.3

hr

12. 5 1.7

Ih/in.'

1, ICO

250

1,720 480

l.OlO

lb/in.'

7, 580 3,080

4, 460

3, 220

13. 570

s __ . t . .5

4. 5 2.28.7

• Corrected on an equivalent area of 30 in.^ i> Length parallul to the cores. Table 2.

Physical properties of the concrete units

Designation

Exterior dimensions

Thickness of

face

shell

Weight

Absorption by

24-hr cold im- mersion

Compressive strength,

gross area

Face shell immersed in M in. of water

Thickness Width Length Dry

Per

cubic

foot of concrete

Per

square

foot of wall

area

Absorption in 3 minutes

Capillary ri^e in first hr

Capili

Height

iry rise

Time

in. in. in. in. lb lb lb % Ih/ft 3 Ih/in.^ glcm 2 in. 17!. hr m » f 7.8 11.9 7.9 1.54 35. 2 119 54 11.1 13.1 860 1.36 6.0 6.7 35

\ 7.9 11.9 7.9 1.4 32.0 128 49 6.5 8.3 1.040 3.6 4.4 16S n » f 7.8 11.9 7.9 1.51 25. 4 91 39 14.0 12.6 6C0 " 0. 33 2.0 5.0 16S

1 8.1 11.8 7.8 1.2 24.1 91 38 13. 2 12.1 1. 150 2.1 5.0 ICS p 8.0 11.9 7.5 1. 36 17.3 83 34 17.2 14.4 800 1.7 4.9 158

a The data in the second line are for a second shipment of the same kind of unit.

[3]
Table 3.

Proportions and water retentivities of the mortars

Mortar

Proportions of ce- ment, lime hydrate, and sand » Cementing materials Average water

content by

weight

of dry materials

Average water

reten- By tivity " vol- ume By weight Cement Lime •>

% %

1 1:0.25:3 1:0. 11:2.6 Portland _ Putty..-. 20.0 72 2__ 1:1:6 1:0. 42:5.

1

___do ...do 23.0 81

3 1:2:9 1:0. 85:7.7 ...do ...do 23.7 88

5 1:1:6 1:0. 42:6.

1

...do Berkeley. 21.3 43

9 1:1:6 1:0. 42:5.

1

...do Standard 20.8 55

10 1:0:3 1:0:3.4 Masonry d 14.9 65

» Proportioning was by weight, assuming that Portland cement

weighed 94 Ib.W, masonry cement (Hy-Test) 70 Ih/ft^, hydrated lime 40

lb/ft 3 and that 1 ft 3 of loose, damp, Potomac River Building sand con- tained 80 lb of dry sand. Putty was made from Standard Lime & Stone Co.'s Washington

brand, powdered quicklime (see table 5. BMS82). Other limes were dry hydrates.

<• Determined according to Federal Specification SS-C-181b.

d Hy-Test masonry cement.

2. Description and Construction of the

Walls

The walls were about 40 in. long, 50 in. high,

and 8 or 12 in. thick. They were supported on

steel channels to facilitate handling and were

sealed at the ends and tops with a mortar

parging % to Yi in. thick. Copper flashings were

built into the walls at the bottom so as to collect and divert to the back face any leakage water

passing through the wall or dropping inside to

Secf/on B-B

/fpprax. 40-—

CopperFJashmgs

Concrefe B/ock

Brick

'

% h: .:, ,wA,. li.,,

/r-onf £/ei^a//on Sec//on AA

Figure 1.—Typical concrete-block wall.

the bottom. A typical concrete-block wall is shown in figure 1, and a typical brick masonry

wall is shown in figure 1 of BMS82. Of the 131

specimens tested, 44 were built of block m, 39

of block n, and 32 of brick c. Experienced masons were employed for the construction of the walls, and all but one specimen was built at the Bureau.

With the exception of walls built of Munlock

brick (brick r, table 1), all the untreated walls were purposely built to be highly permeable.

Most of them were of workmanship B, described

in BMS82, and the units were dry when laid.

3. Designation of the Walls and Waterproofings

The walls were numbered as built and were

further identified by additional numbers to designate the kind of waterproofing and by

letters to indicate the kind of masonry units.

Wlien a wall was waterproofed on the face, the

designation number of the waterproofing was

given after the wall number and before the

letter designation of the kind of unit. For ex- ample, wall B189, built of block m, was waterproofed on the face with cement-water paint 5. The combined number and designation of this wallisBl89-5m.

V. METHOD OF TESTING

1. Water-Permeability Test

The water-permeability test was severe and

of greater duration than the natural wind and

rain storms to which most building walls are subjected, and information of practical value on the permeabilit}^ of the specimen was therefore obtained during an exposure period of 1 day. However, in order to determine the

relative effectiveness of the better waterproofing treatments, the tests were sometimes con- tinued for a maximum period of 5 days.

(a) Apparatus and Test Method

The testing apparatus is described and illus- trated in BMS82. The walls were dry when

placed to form one side of a pressure chamber.

The face of the wall inside the chamber, re- ferred to as the exposed face, was exposed to

[4]
water flowing from a perforated tube at the

rate of 40 gal/hr and to an air pressure equivalent to a 2-in. head of water (10 Ib/ft^) above

atmospheric pressure. The temperature of the

water apphed to the walls was maintained above

the dew point, and the relative humidity of the

air in the testing room was usually between 80

and 90 percent. The backs of the walls were whitewashed so that the penetration of water

could be easily detected by the discoloration

produced.

(b) Observations

The specimens were under continual observation for about 3 hr after starting each test, after which the observer inspected them at increasingly longer intervals.

The following observations were made:

1. Time required for the appearance of moisture (dampness) on the backs of the walls,

above the flashings.

2. Time required for drops of water to appear on the back of the walls, above the flashing.

3. Time required for leakage to flow from

either of the flashings.

4. Maximum rate of leakage, if any.

5. Extent of damp area on the walls, including that produced by the capillary rise of moisture from water on the flashings.

When not exactly determined, the time of

failure was assumed to be the middle of the

interval between two inspections, and the uncertainty of the observation was assumed to be plus or minus one-third of the interval between the two inspections.

(c) Rating of Performance

The arbitrary ratings of wall performance

are the same as those given in BMS82. They

are based on the assumption that visible water

or extensive damp areas on the back or leakage

through the base of a wall would damage plaster,

applied directly to the wall, or would injure

the interior trim or furnishings of a building.

Since the exposure given the test walls was controlled to prevent condensation of moisture on

the backs, no conclusions can be drawn from

the tests regarding the effects of condensation

in building waUs similar to the test specimens.

The following is the system used for rating

wall-performance

:

Excellent (E).—No water visible on back of

the wall (above the flashings) at the end of 1 day. Not more than 25 percent of the wall area damp at the end of 5 days. No leaks ^ through the wall in 5 days.

Good (G).—^No water visible on the back of

the wall at the end of 1 day. Less than 50

percent of the wall area damp at the end of 1 day. No leaks thi-ough the wall at the end of

1 day.

Fair (F).—No water visible on back of the

waU during first 3 hours, but visible at end of

1 day. The rate of leakage through the wall

less than 1 liter/hr at the end of 1 day.

Poor (P) . —Water visible on back of the waU

in 3 hr. or less and at the end of 1 day. Rate of

leakage less than 5 liters/hr at the end of 1 day.

Very Poor (VP).—Rate of leakage through

the wall equal to or greater than 5 liters/hr at the end of 1 day.

There was little practical difference between

the performance of walls rated as "Good" or "ExceUent", and it is possible that walls rated

as "Fair" would be considered to have a satis- factory resistance to rain penetration except

when subjected to rain and to winds of high

velocity for long periods.

2. Outdoor Exposure

After having been tested, some of the least permeable waterproofed walls were stored out- doors at Washington, D. C, for periods ranging

from 3 to 25 months during the interval July

1939 to May 1942. These waUs were then

brought indoors and again tested for permeability.

The monthly maximum and minimum air temperature and the monthly mean of daily

maximum and daily minimum air temperatures

are shown in figure 2, which also shows the

number of thawing cycles per month. The air temperature fell below and then rose above

freezing about 60 times each winter, and the

data (obtained from the Weather Bureau) indi- cate that the air temperature did not rise above

freezing more than once in any one day. The

monthly precipitation for the period January

1939 to May 1942 is given in table 4.

' Leaks are defined as follows: A leak is a flow of water from one or both

fla;ihings, the total rate of flow being equal to or greater than 0.05 liter/hr.

[5]
-11

I 20

10

0

100

80

60

40

20

1 11 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

1 o

) o

o o

o o , 6

Q

o O o

o

Maximum monrh/y temperafure

'^Mean ofdaj/y maximum fempera/i/re

*^ \ 7* -^^o-^—^v- /\

'f ^ ^^^^ ^//-^ / / — k \ 1 r \\ > X*

/ ' ? / \\ 'A ^

/ y.^' / d —

\

^—

FSso^:3»..4 ^y7_. X—

//—

C^' T^J^ean tofda/'/v ^\ ]

' fempero/ijre ^^minimum femperTo/ureK

1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 r 1 1 1 1 1 1 1 1 1 Ju/y Jan. Ja/y Jan. Ju/y

1939 1940 1940 1941 194/

Figure 2. —Temperature record.

Jan

194Z

May

194Z

Table \.~ -Monihly precipitation at Washington, D. C.

Month

January

February... March

April May.

June

July August

September.

October November.

December..

Total

Year

1939

3.4

5. 7

2. 9 3.8

0.4

4. 6 2.0 3.2

6.9

4. 1 1.4

2. 2

1940

2. 1 2.8

3.4

6. 2

3. 1 0. 9 5.7

5.0

1. 3

2. 1 5. 3 2.3

1941

3.0

0.9

2.6

2. 7 1.6 4.4

5.7

1.9

0. 5

1. 1 0.8

3.9

40.6 29.

1

1942

2.5

2.0

6.0 0.5

3.9

Nor- mal

3.6

3.3

3.8

3.3

3. 7

4. 1 4.7

4.0 3.2

2.8 2.4

3.3

42.2

VI. CEMENT-WATER PAINTS

1. Materials and Consistency

The proportions of the materials used in the

cement-water paint treatments are hsted in table 5. The dry powders contained white

Portland cement and hydrated lime, with or without admixtures of hygroscopic salts, water

repellents, diatomaceous silica * an opaque

pigment,^

sand.

or finely screened Potomac River

* Dicalite, a diatomaceous silica, pigment grade, purchased from the

Dicalite Co., New York, N. Y.

5 Titanox, a titanium-barium pigment (Ti02-BaS0i), manufactured by the Titanium Pigment Co., South Amboy, N. J.

The cement contained no integral waterproofing and met the physical requirements of Federal Specification SS-C-191a. The hydrated lime used in paint 5 (table 5) was Certainteed brand dolomitic lime having a plasticity'' figure of 530.

The hydrated lime used in the other cementwater paints was Bei'keley brand high-calcium

lime having a plasticity figure of 120. The amount of water used in mixing the

paints was calculated from that required to attain normal consistency of a paste, as determined according to Federal Specification SS-C158-F4i. Paint 1 was mixed in three different

consistencies, designated as thick, normal, and

thin; the paint of each consistency containing,

respectively, two, three, and four times the

amount of water needed for normal consistency

of the paste, according to the specification.

Paints 2 to 14, inclusive, were mixed in the

normal consistency only (table 5). The grouts

used as the first coats in treatments 16 and 17 were of a relatively thicker consistency than the

paints, in order to more easily maintain the

aggregate in suspension.

i Determined according to Federal Specification SS-L-351, Type F.

[6]
Table 5.

Cement-water paint treatments '

Designation

1_.

2_.

3.-

4...

5..

6_.

7-.

8_-

9.. 10

11. 12

13

14.

16. 17.

Proportions of cementing

materials, b5^ weight

70% cement A, plus 30%

lime C. 100% cements 90% cement A plus 10%, lime C. 60% cement A plus 40%

lime C. 70% cement A plus 30%

lime D. 98% paint 1 98% paint 1 94% paint 1 94%, paint 1. 99.8% paint 1.,- 99.8% paint 1 95% paint 1 97% paint 1 94%, paint 1 W

M , ----

Kind and proportions of admixture, by weight

None.

.do.

-do.

-do_

-do- 2% NaCl. 2% CaCl2 6% NaCl 6% CaCb

0.2% calcium stearate 0.2% ammonium stearate- 5%, Dicalite 3% Ti02-BaS0< 6% TiOi-BaSO,...

(1)

(•)

Normal

water

content by

weight

of dry

materials

Percent

" 100. 8

67.8 78.0

114.0

97.8

99,0

94. 8

89. 4 103.8

102.9

103. 2 116.4 96.0 93.6

(<i)

" Treatments 1 to 14, inclusive, consisted of 2 coats of the same kind and

consistency of paint.

b Cement A was Atlas brand white Portland cement, lime C was Berlce- ley brand high-calcium hydrated lime, and lime D was Certainteed brand

dolomitic hydrated lime.

<^ Normal water content was 100.8 percent. The thick and thin consist- encies of paint 1 contained, respectively, 67.2 and 134.4 percent of water.

<i First, or seal, coat was a grout. The dry materials in the grout con- tained 60 per cent of sand passing a No. 16 sieve and 40 percent of PennDixie brand gray portland cement by weight. Water content by weight

of dry materials was 25 percent. Finish coat was paint 1, normal consist- ency.

e The dry materials in the seal coat contained 56 percent of sand passing

a No.50 sieve, and 44 percent of Medusa white Portland cement, by weight. \Vater content was 36 percent by weight of dry materials. Finish coat was 99.8 percent Medusa white cement and 0.2 percent ammonium stearate, by weight. The water content was 58 percent by weight of dry materials. The paints were prepared by slowly adding

water to the dry powder, with constant stirring

until a thick, smooth paste was formed. Additional water was then mixed with the paste

until the proper paint consistency, as noted

above, was reached.

2. Method of Application and Curing

(a) Preparation of the Walls for Painting

The walls were tested for permeability and

then dried before being prepared for painting.

Dust and loose mortar particles were removed

from the faces, and the moisture content of the

walls at the time of painting was as shown in column 5 of table 6. For "normal" moisture

content, the walls were wetted with one-fourth

of the total quantity of water absorbed during

the permeability test. The water was slowly

and uniformly applied to the face to be painted,

and only a small quantity of water dripped from

the wall. The amounts of water applied for normal moisture content of 8-in. walls of brick c

[

Figure 3.

Brushes used to apply the cement-water

paijits and some other waterproofings.

Brush 2 was a whitewash brusli, brush 3 a fender-cleaning brush, and

brush 4 a roofing brush. and blocks m and n were, respectively, 2.4. 1.8,

and 1.3 Ib/ft^ of wall area. No water was

506934°—43 2 [7]
applied to the walls listed as "dry" in column 5

(table 6), and those listed as "wet" were satu- rated by exposure for 16 or more hours to streams of water from a perforated tube.

About 1 hr elapsed after the walls were wetted

and before they were painted, and no water was visible on the wall faces when the paint was

applied.

(b) Kinds of Brushes

The three kinds of brushes, numbered 2, 3, and 4, shown in figure 3 were used to apply the

cement-water paints. Brush 2 was a whitewash

brush with soft, flexible bristles 3}i in. long.

Brush 3 was a fender-cleaning brush about 6 in. wide and comparable in stifl'ness to the common

scrub brush. The 2-in. fibers were made of

stifle Palmyra {horassus flabellifer) fiber. Brush

4 was made by the Oxfiber Co., Frederick, Md.,

under the trade name of Perry roofing brush.

This brush was 2}^ in. wide and 7 in. long. It was intermediate in stiffness to brushes 2 and 3

and was made of Tampico fibers {agave heter- acantha) 2)^ in. long.

Table 6.Application and curing of cement-water paint treatments

Designation »

iTO. Im. m..

Icc. 1to_

Icc. \m. lm_

\n..

lre._ ICC- Im.

lcc_ iTO. ITO.

lcc_

Im.

lJl__ lcc_ lTO_

lra_

lcc_

lcc_

Im.

lre._ In.. Im.

In.. Im.

iJi..

ITO.

Ire.. 2m.

2n.. 3m. 3m.

3n..

3n.. 4m_ 4m_

Group number '

I, II, III,V,VI_

I, II, III, V, VI _

I, II, III, V, VI_

I.

I.

I.

I, II, III.

I

I

I

II

III.

III.

III. III.

III. III.

IllIII.

III.

IV, v.

IV, V.

IV, V.

IV, VIV....

IV....

IV....

IV_... v.. V . VI.

VI_ VI_

VI.

VI.

VI. VI.

VI.

Type of brusli Moisture content

of backing <i

Normal...

....do ...do

...do ...do

....do do

-.do

1/2 normal. Normal

Yi normal. Normal

Dry....

----do.. do.. Wet....

do..

do..

do.. Normal . .

.

do

dodo

do U normal. Normal . .

.

.--do H normal. Normal

.

do... ..-.do...

....do...

....do...

....do...

do...

do...

.do.

.do.

..do.

..do. .-do-

.-do-

.-do.

..do.

..do.

..do.

Consistency of paint »

Normal.

do..

do...

do...

do... do...

do...

do...

do... do...

do...

do...

.do....

.do....

-do.... .do....

.do.... .do....

.do....

Thin...

do.

do.

do. Thick..

do.

do., ----do.

----do. Normal.

do...

do... do...

do...

do...

do... ...do...

.do.

.do.

-do...

-do... -do..-

.do...

.do...

.do...

.do... .do.-

Amount of dry powder

applied per 100 ft. 2

First coat

lb 10.

1

10. 7

14. 14.3 7.0

13.6

17. 1 7.2

7. 5

15. 4 11.0

17.4

9.6

14.8

I.5. 2 6.7

12.6

13.7 5.2

7. 1 12. 5 12.6

II. 4 9.6

12. 2

19. 1 18.0

18.7

8.4

15.9

16. 5

14. 7 8.8

15. 3 8.0

13.4

9. 1 15.0

10.3

18. 3

11. 1 14. 9

17. 3

9. 6 9.3

10.0

Second

coat

lb

4. 1 8. 1

5, 1

5. 7 2.9

5.0

3.

1

2.7

7.

7. 7 8.4

3.8

4. 2 6.2

5.

1

2.9

7. 3 4,8

2.9

3.

6.

6.

5.

4.

9.

6.

4.

6.

3.2

6.9

4.8 8.6

4. 1 6.5

4. 6 6.5

3. 3

5. 7

3.3

7.3

3. 7 7.6

7. 4

8. 4 3.0 7.6

Two

coats

lb14.2

18. 8

19. 2 20.0 9.9

18. 6 20.2

9.9

14.6

23.

1

19.4 21.2

13.8 21.0

20.3 9.6

19.9

18. 5

8. 1

10.4 19.3

18.7 16.6

14.

1

21.9

25.7

22.3

25.6

11.6 22.8

21.3

23.3

12.9 21.8

12.6

19.9

12.4 20.7

13.6

25.9

14.8

22. 5

24. 7 18.0

12. 3 17.5

Curing conditions '

Temperature Moisture

Normal..

do....

do....

do....

do....

do.... .--.do-..

do....

do....

do.__.

do....

do....

.do. -do.

-do.

.do. .do.

.do. .do.

-do -do

-do

.do.

.do.... .do .do

-do

-do

do.. do.. do.-

do..

35° F.._. 35° F...

120° F_.

120° F.. NormaL

...do...

.do....

-do....

-do...- -do..-

-do...-

.do.... .do...

.do....

« The number designates the kind of paint (table 5), the letter desig- nates the kinds of units in the backing.

i> The walls are divided into groups according to the variable given in section VI-3 of the text.

= Brush 2 was a whitewash brush; brush 3, a fender-cleaning brush; and brush 4, a roofing brush.

d Walls of normal moisture content contained one-fourth the amount

of water absorbed during a permeability test made before treatment.

Wet walls were nearly saturated, with no water showing on the surface. Dry walls were not wetted.

< See table 5 for water content of the paints. -

' Walls given normal curing were stored indoors and wetted twice

daily for 3 days. Walls cured at temperatures of 35° and 120° F. were

placed for 1 week in rooms with controlled temperature, after which they

were stored indoors. Wet-cured walls were wetted twice daily and draped with damp burlap for 1 week. Dry-cured walls were not wetted.

[8]
Table 6.

Application and curing of cement-water paint treatments—Continued

Designation « Group number *> Type of brush Moisture content

of baclving <• Consistency of paint «

Amount of dry powder

ajjplicd per 100 ft.'

First coat Second

coat Twocoats

Curing conditions

Temperature Moisture

5m.

5m.

5n.. 6m.

6n__

7 m.

In.. 8m.

Sn..

Sn.. 9m.

9n.. Sm.

Sn.. 9m.

9n..

9n.. Wm

Wn.

Urn

Urn. 12m

12m

12n.

13ot 13n. 14m 14m

14n. 16m

16n. nx.

VI..

VI.. VI..

VI..

VII.

VII.

VII. VII _ VII. VII _ VII. VII.

VII. VIII

VIII

VIII VIII

VIII IX__

IX.. IX. . IX_. X. .. X... X. .. XI. . XI..

XI__

XI.. XI..

XII.

XII.

XII.

Normal - do...

- ..do... do...

..do.

..do.

.-do. .do.

.do. .do.

l^i normal. Normal...

-...do

.do. .do.

.do-

.do.

.do.

.do. .do.

.do-

.do.

.do.

.do.

.do.

.do.

.do. .do. .do.

.do.

.do.

.do.

Normal.

do.._ do..

do...

.do.

.do.

.do. .do.

.do. .do.

.do. .do.

-do.

-do.

-do-

-do.

-do.

.do.

.do.

.do.

.do.

.do.

.do.

.do.

.do.

.do -do

.do

.do

-do

-do .do

lb

14. 2 9.3

12.4

15. 5

14.3 8.8

13.0 8.8

12. 4 10.9

8. 5 11.7

9.2

12. 7 8.8

11.8

11.2

13. 2 8.9

9.1

8.9 13.9 8.2

do.

44. Oh

36. Oh

26. Sh

3.4

7.2

3. 0

5. 5 3.3

6. 2

8. 1 3.8

6. 5

3.4

6.3 3.6

5.9

3.3

5. 6

4. 2 6.2

2.6

6. 2 5.6

3.7

6. 2 3.2

9. 4 6.4

4.3

5.2

lb18.9

12. 4

21. 9 21.3

12.

21,

11,

1,12.

18. 19.0

12. 3 18.2

12. 6

19.0

12.4

17.7

19.8

13.

1

18.8

13. 1 15.3

11. 5

20. 1 13.8

12. 7 16.7

12. 7

24. 1 16. 7

Normal..

...do...

do... do..

...do... ...do...

- -do... ...do—

do...

.-..do... .-.do...

do...

do...

do. do.

do.

do.

do.

do. dodo,

do.

.do-

-do-

-do-

.do. .do.

.do.

-do- do.

.do. .do.

.do.

e Brush 4 was used to apply the grouting coat; brush 3 to apply the

finish coat.

h Weight of Portland cement and sand (see table 5).

(c) Application of the Paints

The walls treated with cement-water paints

1 to 14, inclusive, were painted with two coats

of the same kind and consistency of paint.

The paint was applied, a brushful at a time, in sweeping horizontal strokes. Care was taken

to thoroughly cover the surface, but pinholes

(formed by the breaking of air bubbles under

the wet film) were not brushed over and filled

if they appeared several minutes after painting an area. The paint was kept at a uniform consistency by frequent stirring. Three walls were given one coat of cement-water paint over

a grout coat (treatments 16 and 17, table 5). The first coat of paint was applied during

the morning hours. The wall was sprayed or

lightly brushed with water about 5 hr afterward,

and was again wetted the next morning before

the application of the second coat. The

amounts of dry powder applied per 100 ft^ of wall area are given in columns 7, 8, and 9 of table 6. The quantity of paint applied to a wall depended upon the surface textui'e of the masomy

units, the kind of brush, the water content of the backing, and the technique employed by the

individual who did the painting. The walls were built in two series. Those in the first series were painted by investigator X, and

those in the second by investigator Y. The

specimens in the second series may be identified

in table 6 by their numbers, which are greater

than B300. Most of the walls were in the fu'st series (painted by investigator X), and the

following observations were made by this in- vestigator or may be noted from an examination

of the data (table 6)

:

1. Nearly 30 percent more paint was applied

to the walls of stone-concrete block (block m)

[9]
when using the fender brush (brush 3) than

when using the other brushes.

2. There were fewer pinholes left in the paint

films on the walls of cinder-concrete block

(block n) when using the fender brush than

when using the whitewash brush (brush 2), but

the type of brush had little effect on the relative

amount of paint applied to such walls.

3. When the moisture content of the backings was normal, nearly 60 percent more paint was applied with the fender brush to the roughtextured cinder-concrete block walls and to the

highly absorptive brick walls than to walls of the stone-concrete block.

4. The relative amount of paint applied to walls of stone-concrete block or of brick c was

considerably less when the backings were wet

and nearly saturated with water than was the

case when they were of normal moisture content. The paint ran down the faces of the

saturated walls B196-1to and B65-lcc and was not readily absorbed, whereas it tended to "cake" when applied to the surface of the dry

wall B62-1CC.

After painting the walls in group I, table 6,

it was decided to use brush 3 for painting the

stone- and the cinder-concrete block walls in groups II to XII, inclusive, and to use brush 4, roofing brush, for painting the brick walls in these groups. The only exceptions to this decision were made in applying the grout

(treatment 16, table 5) for the first coat on

walls B210 and B216. It was found that the

sanded paints could be applied more easily

with the roofer's brush (brush 4) than with

brush 3, and brush marks on the grout

coat were less prominent when brush 4 was

used.

Although investigators X and Y painted

similar walls with the same kind and consistency of paint, using the same brushes, it was

noted that investigator Y used considerably more paint than did X. For walls of the stone- concrete block, the increase in the amount of paint applied by Y over that applied by X

averaged 40 and 140 percent for the first and

second coats. Investigator Y applied less paint for the first coat on the cinder-concrete

block walls, but he averaged 40 percent more

paint for the second coat than did X. Since, as previously noted, the surface texture of the

second shipment of cinder-concrete block n

was smoother than that on the units in the

original group of walls, and since the amount

of paint applied to cinder-block walls by both

investigators was uniformly greater than that

applied to the stone-concrete block, it is evident that surface texture was an important

factor affecting the amount of paint applied,

especially for the first coat. Walls of brick c, normal moisture content, were wet enough to satisfy the painters, but

they still had a considerable absorptive capacity and required more paint than did the

walls of stone-concrete block. The lower

absorptive capacity of the stone-concrete block

of the second shipment (table 2), and used in the second series of walls, probably affected

the amount of paint applied in the first coats.

{d) Curing oj the Coatings

The temperature and moistru-e conditions

to which the cement-water-paint treatments were subjected are given in columns 10 and

11, table 6. Wall coatings cured under "normal" temperature and moisture conditions were stored at room temperature and humidity and were wetted twice daily for 3 days

after application of the second coat. The

average, maximum, and minimum temperatures during "normal" curing of the walls were 75°, 85°, and 60° F, respectively. Similarly, the average, maximum, and minimum

relative humidities, during normal curing, were

55, 70, and 40 percent. The dry-cured walls were stored at room temperature and humidity without wetting. The wet-cured walls were wetted twice daily for 1 week and draped

with wet burlap supported a few inches fi'om

the painted faces. Some of the wet-cured

walls were exposed to temperatures of 35° or 120° F for 1 week, after which they were

stored at room temperature and humidity

without further wetting. It was noted that

the first coats applied to walls B187 and B193

(group IV, table 6) had not quite hardened

after curing for 1 day at 35° F, when

the second coats were applied. The paint

coatings on all the walls were at least

1 month old before they were tested for permeability.

[10]
(e) Condition of the Cured Paint Coatings

The cement-water paint coatings were in- spected after the walls had been cured and

stored indoors for an average of about 1 1 months

and just before they were tested for permeability. Most of the coatings were in excellent

condition, some were slightly crazed, and those on about 20 walls, listed in table 7, were flaked or contained pinholes or larger openings. The

reasons for the blistering and subsequent flaking

of the outer paint films, which occurre-d only in

walls of the first series, were not determined.

The incidence of flaking in paint coatings on

stone-concrete block, cinder-concrete block, and

brick walls was, respectively, 50, 25, and 0

percent. None of the walls given dry curing was flaked, whereas half of those (of the first series) given wet curing were flaked. The walls

of the first series were painted during the late spring and summer, and those of the second

series during the winter, when the relative

humidity of the air indoors (heated air) is usually lower than in the summer. The flaking was most pronounced in the lower portions of the walls, and the suction of the backings, which

had been wetted before the second coat was

applied, was probably low, so that the bond

between the coats in walls given wet curing

may not have developed properly. The rough

texture of the units in cinder-concrete block

walls may have produced a mechanical bond

for the second paint coating, which reduced the

incidence of flaking in these walls. Pinholes and larger openings in the coatings

resulted from the technique used in painting,

which was intended to duplicate job practice, so that exceptionable care was not taken to "touch up" the walls after they had been

painted. Some of the walls listed in table 7 were given additional treatment, and diiplicate

specimens of others were built and tested. (The numbers of the duplicate specimens are greater than B300.)

Coatings of the thin-consistency paint were

very low in hiding power when wet. Since the

hiding power of the paint coatings was lower

when damp than when dry, the coatings containing hygroscopic salts often appeared to have

a lower hiding power than similar ones prepared

without the salts.

An examination was made of the paint coats on some walls that were (larniig(Kl by overturning. It was found that tlie cement-water

paint had penetrated a distance of % in. into some of the cinder-concrete block and to a

greater distance into the joints between these

block. The paint did not penetrate deeply

into the brick or the stone-concrete block, but

did penetrate a maximum of about % in. into

the joints of walls containing these units.

Table 7.Tabulation of defects in cement-water paint

coatings "

Wall Designation

B162-_.

B164._..

B181_

B315_

B196___.

B202_.__

B171_-_ B182

B60__, B177_

B183___. B178—

B184-_„.

B179__^.

B186_^__ B107--

B188_-_-

B189-^__

B200-__. B220-^-

B221.„.

Xm

Im

Im.

In.. Im.

In-.

Icc.

Im.. Im. 2m. 3mim.

5m. 7m.

14m.

Group 1

I, n III, V, VI

I

I.

III.

IIIIII- IIIIII.

IV, V.

IV, VIV-.

VI..

VI..

VI.

VI.

.

VII.

XTKind and extent of defects

«

Severe flaking in lower half of

wall. Moderate flaking in lower half of wall. Severe flaking; many pinholes. Openings, pinholes near the

joints. Severe flaking. Slight flaking in two blocks.

Slight flaking in one block.

Slight flaking at openings near

the joints. Openings near the joints. Severe flaking, lower two-thirds

of wall. Slight flaking.

Severe flaking. Severe flaking in lower half of

wall. Opening in face. Slight flaking over joints.

Slight flaking. Do. Do, Moderate flaking.

Slight flaking.

Severe flaking. Do.

« The paint coatings were examined after caring them and before the

walls were tested for permeability. Slight defects in the coatings on some

walls are not reported in the table.

•> The walls are divided into groups according to the variable given in section VI-3 of the te.\t.

« Flaking; Loss of outer paint film after preliminary blistering of the second paint coating, usually over small isolated areas. Openings were

formed by air bubbles (pinholes) or by the failure of the paint iilm to cover and' fill rough-te.xtured areas.

3. Some Factors Affecting the Permeability OF THE Cement-Water Paint

Coatings

Data obtained from permeability tests made

on walls painted with cement-water paints are given in table 8. The walls are listed by groups

in tables 6 and 8, according to the following

variables

:

Group Variant

I Brushes.

II Moisture content of backing.

Ill Water content of paint.

IV Temperature of curino;. V Moisture condition of curing.

VI Cement-lime paint mixtures.

[11]
Group Variant VII Admixture of hygroscopic salts. VIII Admixture of hygroscopic salts (dry

curing)

.

IX Admixture of water repellents.

X Admixture of diatomaceous silica. XI Admixture of an opaque pigment.

XII Grouting of the first coat.

The data in the first and second lines for each

wall are for tests made, respectively, before and

after treatment (see column 4). Data for tests made after additional treatment or after a

period of outdoor exposure are given in the

bottom lines.

Table 8.

Permeability of walls treated with cement-water paints

Wall Designation a Group !> Condition of wall, and period of outdoor exposure

Time = to failure as indicated byDampness on

back

Water

on back

Leakage

from

flashings

Maxi' mum rate

of leakage per hour

Area damp in

1 day

B162.

B310

B172.

B54..

B163.

B173.

B56..

B164.

B313.

B181.

B315.

B57..

B180.

B191-

B62.

B196

B312.

B202

B65_.

B171

B323

Im

Im

In.

Icc.

Im.

In.

Icc.

Im.

Im.

In.

In.

Icc.

Im

ln_

Icc.

Im

Im

In.

Icc

Im

Im

I, II, III, V. VI,

I, II, III, V, VI

I, II, III, V, VI

I

I

I

I, II, III

I

I

I

I

I

II

II

II

II

11

II

II

in

III

(Before treatment-_-

After painting <•

, Additional paint treatment_ May 1940 to Aug. 1941 (Before treatment

^After painting [Mar. 1941 to Mar. 1942

I Before treatment

< After painting

[Sept. 1939 to Aug. 1941 (Before treatment

< After painting

[July 1939 to Aug. 1941 {Before treatment

After painting

Sept. 1939 to Aug. 1941 (Before treatment

< After painting

[Sept. 1939 to Aug. 1941 IBefore treatment__

After painting

[July 1939 to Aug. 1941__ IBefore treatment

{After painting [Mar. 1940 to Aug. 1941 IBefore treatment

{After painting [Mar. 1941 to Mar. 1942 (Before treatment

Lifter painting <i [Mar. 1940 to Aug. 1941 {Before treatment

After painting d Mar. 1941 to Mar. 1942 (Before treatment

^After painting

[April 1940 to Aug. 1941

{Before treatment _ After painting Mar. 1940 to Aug. 1941. (Before treatment

< After painting [Mar. 1940 to Aug. 1941. (Before treatment

{After painting

[April 1940 to Aug. 1941. (Before treatment

{.^fter paintin? <i [April 1940 to Aug. 1941. (Before treatment

•^."i-fter painting [Mar. 1941 to Mar. 1942. (Before treatment

^After painting <> [April 1940 to Aug. 1941. {Before treatment

After painting... April 1940 to Aug. 1941.

(Before treatment

J After painting d

I Additional painting [May 1940 to Aug. 1941... (Before treatment.

{After painting

[April 1941 to April 1942.

hr0.07

.9

18 ±4

10 ±2

0.06

11310 ±2

0. 07

11 ±3

280.1

hr0.08

2.2

0. 07

.07

18 ±3

0.15

5.2

11 ±3

0. 05

25490.2 42

10.1 3.8

5.6 0.03

.07

.....

.15

14 ±5

0. 06

11 ±2

0. 03 .08

.07

.03

.2

.6.03 1.4

1.8

0. 05

4

1. 5

0. 03

3.3 0.5

.05

1.3

3. 7

0. 05

4.6

4.4

0. 03

.03

.1.3.03

.04

15 ±5

0. 25

.07

13 ±6

3.6

0. 03

.07

.07

.06

15 ±5

0. 03 62 ±8

1.4

0. 08

10 ±3

3.4

0. 07

.4 10 ±3

10 ±2

0. 05

10 ±2

10 ±2

.03

0. 09

.07

hr0.2

6.0

0. 08

39 ±5

0. 07

52760.2

.05

0.3

.4

14 ±5

0.1

.07

.07

.03

.03 1.0

0.8

.3

.2

13 ±6

15 ±6

0. 06

15 ±6

0.3

0.3

.2

.09

Liters 950.97

126

0.09

137

0. 13

.1

14.

1

0

0

10

0

0

1420.09

92

0

0

9

0. 14

0 106

00

8.2

92

1.4 1.5 760

0

0.2

.14 62

0. 04

0

52

0

0

710

0

118 . 0

0

104

0

0690

0

1335.5

0

0

14700

Percent

95

45

510

55

1 1080

1095

0

1 80

65

1580

0

1 95

040

92

75

70

95

0

5590

65

45

50

10

15

65

15

9590

50

85

8

5 100

75

1590

35

45

950

2090

020

95

25

40

100

5030

30

90

270 See footnotes at end of table.

[12]
Table 8.

Permeability of walls treated with cement-water paints—Continued

Designation " Group *> Condition of wall, and period of outdoor exposure

Time ' to failure as indicated byDampness on

back

Water

on back

Leakage

from

flashings

Maxi- mum rate

of leakage

per hour

Area damp in '

1 day

In.

Icc.

Im.

Im

.

In.

Icc.

Icc.

Im.

Im.

In.

In.

Im.

In.

Im.

In.

Im.

In.

2m

2n

3m

3771

3n.

3n.

im

im

in.

111.

III_

III.

III.

in.

III.

III.

IV, V.

IV, V.

IV, V.

IV, V.

IV.. ._

IV

IV

IV.... V

V

VI.

VI.

See footnotes at

VI

VI

VI

VI

VI

VI

VI

end of table.

(Before treatment

.\fter painting <i Additional treatment - April 1940 to -\ug. 1941. Before treatment..

After painting <i Additional treatment.

.

May 1940 to .^ug. 1941.. {Before treatment

iVfter painting d May 1940 to Sept. 1941. (Before treatment.

< After painting [Mar. 1941 to Mar. 1942. (Before treatment

.\fter painting ^ May 1940 to Sept. 1941.

I Before treatment

^.'^fter painting.. [June 1940 to Sept. 1941. fBefore treatment.

\After painting

[Before treatment

^.'Vfter painting <i [-Mar. 1940 to .iug. 1941.. IBefore treatmentl.^fter painting

[.\pril 1941 to .^pril 1942. Before treatment

-\fter painting ^ -^.dditional treatment June 1940 to Sept. 1941. [Before treatment

^-\fter painting

[-•Vpril 1941 to .4.pril 1942. [Before treatment

^-\fter painting

[-A.pril 1940 to -\pril 1941-

[ Before treatment

•^.\fter painting

[-\pril 1940 to Sept. 1941- IBefore treatment

j-\fter painting ^

[.A.pril 1940 to -A.ug. 1941.. {Before treatment

-Yfter painting June 1940 to Sept. 1941-

.

fBefore treatment

t.-Vfter painting

[Before treatment

<.\.fter painting [June 1940 to Sept. 1941-

[Before treatment

•^-\fter painting <i [June 1940 to Sept. 1941..-. fBefore treatment

lAfter painting — (Before treatment

(After painting <i (June 1940 to Sept. 1941 {Before treatment

.\fter painting Mar. 1941 to Mar. 1942

[Before treatment

<-A.fter painting [June 1940 to Sept. 1941 [Before treatment

•^-ifter painting [March 1941 to March 1942- [Before treatment

<-\fter painting ^ [June 1940 to Sept. 1941 (Before treatment...

<.ifter painting

[-A.pril 1941 to April 1942 (Before treatment

•!.\fter painting (June 1940 to Sept. 1941

ftr 0. 03

. 1

. i .3.02

.85

4

3. 2

0. 05

10 ±2

9 ±2

0.06

6119 ±3

0. 03

9 ±3

18 ±3

0.03

.4

.7.15

6.1

0.03

15 ±6

2.8 0.04

hr

0.03

.1.2

1.8 0.03

3.6

280.07

18 ±4

0.08

.05

25

0. 05

.9 3.5

0. 22 10 ±2

0.04

.04

0.04

.08

18 ±4

0. 07

0. 05

5.7

5.7

0. 03

10 ±3

4.5 0.05

14 ±6

11 ±3

0. 02

18 ±4

10 ±2

0. 07

15 ±6

0. 04

17 ±4

53

0.05

4.5

.07

.05

.06

.03

0.08

.05 "73"""

0.08

0. 03

1. 5 0.06

9 ±2

58

0. 04

.03

9 ±3

0.07

280.02

.3

.2 0.05

.02

.55 0.05

3.5 0.05

4

11 ±3

0.05

2.8

6.2 0.02

15 ±6

18 ±3

.08

.06

15 ±6

0.02

26 ±2

ftr.07

.2

1.3 3.8

0.2

3.6

.2

18 ±4

0.09

39 ±6

0.07

.2

4 ±1

0. 35

.15

".'04'

.02

2.5 0.2

15 ±6

39 ±6

0. 07

39 =h6

0.2

.04

.2

.06

.'2"

.08

1.2

1.7 0.02

2.5 0.2

.1 15 ±6

15 ±6

0.1

Liters 53

232.8

379

0. 65

0

0

1190.2

0

138

0.08

40

0

0 107

1.0

72

0

0

129

0

0

92

1.8 0

0

1010

.17

940.08

.05

92

0

.1 72

0

072

0

0

130

086

0

0

93

0

0

45089

0

0 130

0

090

1.7 0.9

10600.2

104

0

0

1200.07

.21 88

00

Percent

90

[13]
Table 8.

Permeability of walls treated with cement-water paints—Continued

Wall

B189_

B320.

B195-

B199-

Deslgna

tion «

5m ^

6mB205 6mB200 7TOB211_ 7mB206-

B212-

B316-

B207-

B213-

B208_

B214.

B209-

B215.

B318-

B218.

B217-

B219-

B251-

B220_

B321_

B252_

B222_

B254.

B221_

B325.

877! .

871-

871-

977i_

971-

87n871 —

9771.

971-

971-

10771.

11771.

1177..

12m_

12771.

1271..

13777-.

137i..

147n.

14771.

Group

VI..

VI..

VI..

VII.

VII.

VII.

VII.

VII.

VII.

VII.

VII.

VII.

VIII

VIII

vin

VIII

VIII

IX..

IX..

IX..

IX. .

X. ..

X...

X. ..

XI. .

XI..

XI..

XI..

Condition of wall, and period of outdoor exposure

(Before treatment

<After painting (jmie 1940 to Sept. 1941. IBefore treatment

•^After painting [Mar. 1941 to Mar. 1942. [Before treatment

After painting

I June 1940 to Sept. 1941.

(Before treatment

^After painting (June 1940 to Sept. 1941.

f Before treatment

(After painting

/Before treatment

(After painting

fBefore treatment

(After painting

(Before treatment Mfter painting

I June 1940 to Sept. 1941. IBefore treatment

{After painting [June 1940 to Sept. 1941. {Before treatment

After painting Mar. 1941 to Mar. 1942. (Before treatment

<After painting [June 1940 to Sept. 1941. (Before treatment

< After painting

I June 1940 to Sept. 1941.

(Before treatment

^After painting . [July 1940 to Sept. 1941.. (Before treatment

•^.\fter painting

(July 1940 to Sept. 1941.. (Before treatment

s After painting

[July 1940 to Sept. 1941.. (Before treatment

After painting

(July 1940 to Sept. 1941.. (Before treatment

After painting

April 1941 to April 1942.

(Before treatment

^.•Vfter painting

[July 1940 to Oct. 1941..

( Before treatment

^-Vfter painting

(July 1940 to Oct. 1941- Before treatment

(After painting

(July 1940 to Oct. 1941-. {Before treatment

After painting Aug. 1940 to Oct. 1941.

(Before treatment

< After painting <• (July 1940 to Oct. 1941. /Before treatment

(After painting {Before treatment

j\.fter painting Aug. 1940 to Oct. 194XBefore treatment

After painting- Aug. 1940 to Oct. 1941. /Before treatment

(After painting /Before treatment

(After painting d /Before treatment

(After painting

Time « to failure as indicated byDampness on back

hr0.06

18 ±4

11 ±3

0.05

19 ±4

17 ±4

0.04

16 ±6

28

0.05

4.7

80.02

.3.02 2.3 0.04

19 ±3

0.04

9 ±2

260.03

.25

11 ±3

0.1

290.04

8 ±2

530.05

2.8

6.3

0.06

10 ±3

340.04

.3.4 0.06

11 ±3

10 ±2

0.03

6.3

11 ±3

0.07

6.2

1

0. 04

5

11 ±2

0. 02

18 ±3

63 ±8

0.03

5

11 ±2

0.04

3.6

0. 03

2.9

5

0. 04

5. 3

0. 04

26

8 ±2

0. 04

6 ±1

26

0. 02

11 ±2

0. 05

3. 5

0. 06

4.8

Water

on back

hr0.08

25 ±1

0.07

39 ±6

0.05

.03

.08

.05

5.5

0.08

.05

530.03

280.08

.07

.03

.05

.05

.07

.03

.07

Leakage

from

flashings

hr

39 ±6

0.07

.2

.06 5.8 0.2

.07

39 ±6

0.2

.09

.01

3.2

0. 19

.07

15 ±6

0.2

.09 5.5

15 ±6

0.2

39 ±6

0. 06

11 ±3

0.01

16 ±6

2.6

0.2

.07

.2

.02 "3'i"

0. 02

11 ±3

0. 2

15 ±6

0. 05

19 ±3

17 ±4

0.2

.05

18 ±3

0.2

Maxi mum rate

of leakage per hour

Liters

810

0

149

0 .07 116

0

0

108

0

0790.3

1370.2

1130.2

125

0

0 1340

089

0 .16

83

0

0680.75

0

125

0

0 126

0. 13 .06 880.04

0 1120.07

0 1040.03

.2

107

0

0 1380

0 118

00

37

0

1280.4

(I 137

0. 07

44

0.

1

.04

1110

089

0. 1 85

0 1140

Area damp in

1 day

Percevt

100

82095

0

3 90

6

1

100

30

2 90

20

10054

100

3095

25

260

10 10025

095

45

20

100

8

090

30

25 100

20

890

15

1 40

610

10045

10 100

50 10035

770

0

10

10076

2090

30

75

4

1

10025

1 86

5 1007690

30 See footnotes at end of table.

[14]
Table 8.

Permeability of vxills trealed with cement-water paints—Continued

Wall Designation » Group i" Condition of wall, and period of outdoor exposure

Time " to failure as indicated byDampness on

back

Wiitcr on back

Leakage

from

flasliings

Maxi- mum rate

of leakage

per hour

Area damp in

1 day

Rating

B253

B210

B216

B123

14m.

16m

16m.

17x.

XI.

XII xn

XII

Before treatment

After painting ... Aug. 1940 to Oct. 1941.

(Before treatment

After painting July 1940 to Sept. 1941. {Before treatment

.\ftcr painting July 1940 to Oct. 1941.. /Before treatment

\After painting

hr0.03

2.5

63

0. 03

11 ±3

"'"0.04

35

1110.2

ftr..03

Ar.03

14 ±6

0.2

".m

"."08

Liters

1350.2

0

96

0

0 123

0

0 103

0

Percent

70

10

1

100

10

090

0

065

0

VP

FE

VP

aE

VP

E

E

VP

E

» The number designates the kind of paint (table 5); the letter desig- nates the kinds of units in the backing.

b The walls are divided into groups according to the variable given in section VI-3 of the text.

(a) Kind of Brush

The effect on permeability of the kind of brush used to apply paint 1 to walls of stone- or cinder-concrete block or of brick is shown by

the data given for the walls of group I, table 8. The moisture content of the backings, the consistency of the paint, and the curing conditions were normal, as given in table 6. The ratings

of these walls, listed in table 9, indicate that

brush 3 (fender brush) was the most effective

and brush 2 (whitewash brush) the least effec- tive for general use on all three kinds of backings. Brush 4 (roofing brush) was nearly as

effective as brush 3, and brush 2 was the least effective when used on the rough-textured

cinder-block backings.

Table 9.

Effect of kind, of brush on permeability »

Kind of brush

Ratings of walls of different units

Block TO Block n Brick c

Whitewash brush (No. 2) Fender-cleaning brush (No. 3).-. .. . Roofers brush (No. 4)

0 F, E

' G. E

F

d VP, P

GG

FE

G

« Walls painted with cement-water paint 1 (group I, tables 6 and 8).

>> If 2 ratings are given, they are for separate walls.

« Moderate flaking noted in outer paint film before the test,

d Severe flaking and many pinholes noted in outer paint film before the test.

e Outer coating badly flaked; test made after repainting.

(&) Kind oj Backing and Its Moisture Content

The performance ratings of the walls of group

II (tables 6 and 8) are given in table 10. The

0 The uncertainty of the observation is given if it exceeds 10 percent of the total elapsed time. Dashes indicate no failure of the wall.

d Some flaking or other defect noted in second paint coat before permeability test was made (see table 7).

« Possibly G.

walls were painted with paint 1 and were cured

under normal conditions. Walls of normal or wet moisture content were rated G or E. Two

of the three walls that were not wetted but were

dry when painted were rated F. The other, of cinder-concrete block, was rated 6. The wetted

walls were nearly saturated, but no water was

visible on the backings when they were painted.

Paint coatings applied to the wet backings were most resistant to water penetration, but a wide

range in moisture content of the backings

(normal to wet) had little important effect on

permeability. The kind of masoniy unit in the

backings had no important effect on the per- meability of the paint coatings applied to avails of normal or wet moisture content.

Table 10.

Effect of kind of backing and of moisture

content on permeability »

Kind of masonry unit in backing

Ratings of walls ^ of different moisture contents when

painted

Dry Normal Wet

Stone-concrete block m F

GF

«G, E

G

G

dG, E

E

G

Cinder-concrete block n

Brick c

> Walls painted with cement-water paint 1 (group II, tables 6 and 8).

i> If 2 ratings are given, they are for separate walls.

o Outer coating badly flaked; test made after repainting.

d Severe flaking noted in outer paint coating before test.

(c) Paint Consistency

The effects of paint consistency on the permeability of the walls in group III are given m

506934°—43 3 [15]
table 11. The thin, normal, and thick consistencies of paint 1 contained, respectively, 134,

101, and 67 percent of water by weight of dry

powder (table 5). The data (tables 8 and 11)

show that walls of cinder-concrete block and of

brick (walls B182 and B60), treated with thin

paint, were rated VP and F, respectively. These

walls were again tested after having been re- painted with one coat of the same consistency, and

their ratings, not sho^vn in table 1 1, were raised

to P and G, respectively. Of the two walls of stone-concrete block, treated with thin paint, one was rated VP and one E. However, nearly

twice as much paint was applied to wall B323,

rated E, as was used on wall B171 (table 6). The walls of concrete block treated with pamt of

normal or thick consistency, and not damaged

by flaking, were rated G or E. The brick wall

treated with paint of normal consistency was

rated G; those treated with thick paint were

rated P or F. The data are meager, but they indicate that

the thin paints applied to concrete-block walls were ineffective unless heavy or repeated applications of the paint were made.

Table 11.

Effect of paint consistency on permeahility^

Consistency of paint

Ratings of walls = of different ui'its

Block m Block n Brick c

Thin VP. E VP F

Normal _ dp, E G G

Thick iF, E G P, F

a AValls painted with cement-water paint 1 (group III, tables 6 and 8)"

t" Paint 1, of thin, normal, and thick consistency, contained, respec

tively, 134.4, 100.8, and 67.2 percent water, by weight of dry powder.

<^ If two ratings are given, they are for separate walls.

1 Severe flaking noted in outer coating before test.

(d) Curing Conditions

The effects of temperature and moisture conditions during the curing of the cement-water

paint coatings applied to walls built of concrete blocks (groups IV and V, tables 6 and 8) are given in table 12. Wall B187-1to given a wet

curing at 35° F was rated F, but the comparison

specimen, built of cinder- instead of stone- concrete block, was rated G. The walls given

wet curing for 1 week at a temperature of 120°

F showed a satisfactory resistance to water

penetration, and in general the range in temperature bad no important effect on permeability.

Similarly, the walls cured at normal temperatures and under the range of moisture conditions of dry, normal, and wet had an average

performance rating of G, and the effects on

permeability of the differences between the

given moisture conditions during curing were

unimportant. It should be noted, however,

that the test walls were of normal moisture

content when painted, and that cement-water

paint coatings applied to dry building walls

exposed without wetting to the wind and sun may be more permeable than those on the test specimens.

Table 12.

Effects of temperature and moisture conditions during curing on perm,eability *

Type of curing i" Ratings of walls " of different units

Temperature Moisture condition Block m Block n

35° F Wet F

G iG,E

'G, E

G

G

G

G

dp, B

G

Normal

(Dry

< Normal

120° F

hVet Wet

" Walls painted with cement-water paint 1 (groups IV and V, tables

6 and 8 respectively)

.

b Walls given normal curing were stored indoors and wetted twice

daily for 3 days. Walls cured at temperatures of 35° and 120° F were

placed for 1 week in rooms with controlled temperature, after which they were stored indoors. Wet-cured walls were wetted twice daily and

draped with damp burlap for 1 week. Dry-cured walls were not wetted.

" If 2 ratings are given, they are for separate walls.

d Outer coating badly flaked; test made after repainting.

• Severe flaking noted in outer coating before test.

(e) Kind of Paint and of Admixtures

The effects of the relative proportions of

Portland cement and hydrated lime and of the

kind of hydrated lime on the permeability of the

walls treated with cement-water paints may be

noted from the data in table 8 for the waUs

listed in group VI. There was no important difference between

the average permeability of the waUs treated

with paints 1 to 5, and aU but a few of the walls

showed a satisfactory resistance to water

penetration. Five of the walls whose coatings were not flaked when tested gave E performances; and of the remainder, two were rated G,

two F, and one P. In general, the painted

walls built of stone-concrete block were less permeable than those built of cinder block.

The cinder-concrete units were more difficult to paint than the stone-concrete block, and it is probable that flaking or pinholes in the paint

coatings affected the permeability of the speci-

[16]
mens more than did the relative proportions of cement and hme.

The admixture of hygroscopic salts in comentwater paints had no important effect on the

permeability of the test walls (see table 13).

The walls treated with paint 1 and given either

dry or normal curing were in most cases slightly

less permeable than those treated with paints

6, 7, 8, or 9, which contained sodium or cal- cium chloride. The backings of the specimens were of normal moisture content, and it is possible that the admixture of hygroscopic

salts in paints applied to dry backings or cured

outdoors without wetting may be of benefit.

Table 13.- -Ejfed on permeability of hygroscopic salts in cement-water paint «

Paint »

Kind and proportion, by weight,

of hygroscopic

salts

Rating of the walls »

Normal curing of walls of—Dry-curing of walls of—

Sodium

chloride Calciumchloride Block m Block M Block m Block n

% %

1 0 0 AG.E G G G

6 2 0 G F

7 0

6

2 F

8 0 a p'e G F

"

9 0 6 G F G F, E

" Data on the application and curing of the paint and on the permeability

of the walls are contained in tables 6 and 8; walls painted with paint 1 are listed in groups I and V, the others in groups VII and VIII. The composition and proportions of the paints are given in table 5.

" If two ratings are given, they are for separate walls,

d Outer coating badly flaked; test made after repainting. The peiTneabUity of the paint coatings containing calcium or ammonium stearates (paints

10 and 11, table 5) may be obtained from the

data in table 8 for the walls in group IX. These

walls were rated G or E and their performances were comparable to those of similar walls

(group I) treated with paint 1, prepared without ammonium stearate. No significant dif- ferences were noted in the permeabilities of

coatings of paints 1, 10, or 11. The effects on permeability of the admixture

of 5 percent of Dicalite (diatomaceoas silica) in cement-water paint may be determined by

an examination of the data in table 8 for walls

B310-lm and Bl72-ln of group I and for walls B321-12m and B252-12« of group X.

The data .clearly indicate that coatings containing Dicalite, paint 12, were significantly more permeable than similar ones prepared

without it. The walls treated with paiat 12

were rated F when tested immediately after painting, those treated with paint 1 were rated

Got E.

Data on the permeability of concrete-blodc

walls painted with cement-water paints 13 or

14, containing Titanox, an opaque pigment,

are given in table 8 for walls of group XI.

These paints were eft'ective on backings of stone-concrete block m and the walls were

rated G. Cinder-concrete block walls, similarly treated, were rated F. Paints 13 and 14 were comparable in eftectiveness to paint 1 when applied to stone-concrete block walls,

but they were significantly more permeable

than paint 1 when tested immediatel3' after application to cinder-concrete block walls.

(/) Use of a Grout Coat

Cement-water paints containing fine sand

(treatments 16 and 17, table 5) were used for the first coat on walls of stone- or cinder- concrete blocks. The application of a grout to wall B210-16m, listed in group XII of table 6, resulted in a considerable loss of the coarser

particles of sand, and much less grout adhered

to this wall than is indicated in table 6. The

sanded paints bonded well to the coarse-tex- tured units in walls B216-167i, and B123-17-X,

and the loss of aggregate from these specimens was small. The walls of cinder-concrete block were rated E, after painting, that of stone- concrete block was rated G, and the data show

that the grouts were most eft'ective when

applied to the coarse-textured units.

4. Effect of Weathering Exposuee on

Permeability

The periods of outdoor weathering to which

the cement-water paint walls were subjected,

given in table 8, show that the average durations of exposure for walls of the first and second

series were, respectively, 16 and 12 months.

Some of the paint coatings were so crazed,

flaked, or weather-stained after exposure that

their repainting, for the sake of appearance, was desirable. The coatings containing stearate waterproofings (paints 10 and 11) were less weather-stained than were others prepared without stearates. Crazing was more severe over the

joints of concrete-block backmgs than over the

[17]
units, and the reverse was true for most of the

coatings appKed to brick backings. The paint

films on many of the cinder-concrete block

backings were spalled over small isolated areas because of popping of the concrete in the faces

of the units.

The weathering exposure did not, in general,

have an important efl'ect on the permeability of

walls treated with cement-water paints. A sum- mary of the ratings, before and after weathering, of walls in the first and second series is given in table 14. Walls of the first series were

significantly less permeable after exposure than

before. The ratings of walls in the second series were higher imm^^diately after painting than

those of the walls in the first; after exposure,

they were lower. The average weights of the

dry powder applied to backings of concrete

blocks m and n of the first series (walls with

numbers lower than B300) were, respectively,

12 and 20 Ib/ft^, and the amount applied to backings of block m or n of the second series was

20 lb. The cmder-concrete block used in walls

of the second series had a smoother surface texture than those used in the walls of the first series, but the paint coatings on walls of the

second series were thicker than those of the

first. The data indicate that thick coatings of cement-water paints may be more effective

when first applied than thinner coatings, but

are less effective after weathering exposure.

Table 14.

Effrrt of weathering exposure on permeability

Number of walls in each rating classification

Wall-performance First series » Second series » rating

Before After Before After exposure exposure exposure exposure E 6 9 12 0 a 29 37 0 6 F - 14 i 1 7 P 5 3 1 I VP 1 1

» Numbers of walls in first series were less than B300; those in the second series were greater (Tables 6 and 8). An examination of the walls after the

weathering exposure indicated that the coatings on the most permeable specimens contained

cracks over the joints equal to or greater in

width than 0.01 in. Nearly all the walls listed as having flaked coatings were rated G or E

after the weathering exposure, whereas most of

the walls containing pinholes or larger openings

in the coatings were given lower ratings.

The walls in group X (table 8) treated with

coatings containing Dicalite were less permeable

after the weathering exposure than before, and

their performances were comparable to those of

walls treated with paint 1. Except for the differences noted between the

permeabilities of walls of the first and of the

second series and for those noted in group X

(table 8), the weathering expostwe had no

important effect on the permeability of any

kind or group of specimens.

5. Discussion

The masonry walls treated with cementwater paints were, with few exceptions, highly

resistant to water penetration both before and

after weathering them outdoors. Walls of coarse-textured cinder-concrete block were

painted to best advantage when using a stiff" brush, such as the fender brush. Even then,

pinholes or larger openings were often left after the painting, and the most eft'ective treatment

for coarse-textured walls was the application of a grout coating (a paint containing fine sand)

for the first coat. Walls so treated were

rated E, both before and after weathering.

Although a range in moisture content of the

backing, from that of near saturation to a damp

condition, had little effect on permeability,

dry walls that were painted without prewetting were significantly more permeable than those

that were wetted. The paint coatings of normal consistency were less permeable than

those of thin consistency. A coating of thick

consistency applied to a brick wall was rated

lower than one of normal consistency.

The amount of paint applied per unit of waU

area increased with the ruggedness of the sur- face and was greatest for walls of cinder-concrete block. For units of like surface texture,

thick paint films resulting from excessive

amounts of paint were more resistant to water

penetration, when first applied, than thinner

coatings. After exposure to the weather, the

thick coatmgs were less resistant. The average

perform.ance of the thinner coatings of normalconsistency paint, applied to walls of the first series, was higher after weathering than before.

[18]
The range in the relative proportions of Portland cement and of hydrated lime la the

paints, as well as the number of treated specimens, was limited. Alost of the walls were

highly resistant to water penetration both

before and after weathering, but the data do

not clearly indicate that any one of the paints,

1 to 5, inclusive, was superior to the others.

Paints containing admixtures of hygroscopic

salts, water repellents, diatomaceous silica, or an opaque pigment were no more effective

than similar paints prepared without these

admixtures. The range of curing conditions to which the walls were subjected did not have an

important effect on their permeability.

The assistance of James N. Calhoun (investigator A") and Harold L. Manley (investigator

Y) in constructing the wall specimens, preparing and applying the paints, and malting the

tests is gratefully acknowledged. Mr. Callioun

also determined the physical properties of the

various paint mixtures and gave valuable suggestions during the preparation of tliis report.

VTI. PROPRIETARY WATERPROOFINGS

APPLIED TO THE EXPOSED FACES

OF THE WALLS

1. Pigmented Surface Coatings

The permenbilities, before and after treat- ment, and after weathering outdoors, of walls

treated with pigmented proprietary waterproofings are given in table 15. The table

gives the designation of the walls, their condition when tested, data obtained from the tests, and the performance ratmgs.

Table 15.

Permeability of walls treated with pigmented proprietary surface coatings

Trade name

AquaplexDricoatDrye

Maiiro Brusli-Tex B198_

Maure Plaster Special B103_

Wall No.

B256_

B257_

B258_

Bill

B326

TymstoneVarcraftB303_

13223

1b255_

Designation "

21n.

22re_

23w.

24cc,

29r/t

29?i

Condition of wall and period of outdoor exjjosure

("Before treatment

\After treatment

(Before treatment

< After treatment

[Aug. 1940 to Oct. 1941 _ IBcfore treatment

< After treatment

[Aug. 1940 to Oct. 1941.

/Before treatment.

\After treatment..

Before treatment

After treatment

Dec. 1941 to May 1942.

fBefore treatment.

\After treatment..

Before treatment

After treatment. _ _ July 1939 to Aug. 1941.

Before treatment As received Nov. 1940 to Jan. 1942. Feb. 1942 to June 1942

(Before treatment

<After treatment [Aug. 1940 to Oct. 1941 /Before treatment

\After treatment

» The number designates the kind of waterproofing treatment, the

letter designates the kind of units used in the backings.

^ The uncertainty of the observation is given if it exceeds 10 percent of the total elapsed time. Dashes indicate no failm-e of the wall.

Time ^ to failure as indicated byDamp

on back Water

on back

Ar.

0. 03

. 5.03

.1.2.04

. 1 .2

.02

.4

.08

17 ±3

1.3

0. 05

.3

.06

18 ±4

1. 5

0.04

.4

.3.04

.03

hr.0.04

2.0

0. 03

1.0

0. 2

0. 05

2.0 0.3

0. 13 1.7

0.1

0. 1 1.3

2.5

0.08

2

1.

1

0. 04

.5

Leak

from

flashing

hr.0.03

14 ±6

0.03

.6

.4.04 .3

.4

.4

1.7

0.3

0. 2

. 2

15 ±6

0.2

1.3 3.9

0.04

.05

Maxi- mum

rate of leakage

per hour

Liters 75

4.6

117

10

122

1922

108

0

0

0

0

0

95

3.5

0.4

67

14

Area damp in

1 day

Percent

70

35

70

3025

7540

25

10

100

5 60

1011 100

95

290

0

0

10

10080

7570

50

Hating

VP

P

VP

VP

VP

VP

VP

VP

VP

VP

VP

GFVP

VP

VP

E

P

(-") B

E

E

VP

P

P

VP

VP

' Backing built of Waylite concrete block laid in and coated with Tymstone mortar,

"d No test made.

(a) Aquaplex

Aquaplex S-6 and Aquaplex Q-68 were emulsified

resin paints (waterproofings 21, 22, and 23, table 15), manufactured by the Resinous Products Co., Philadelphia, Pa. Aquaplex S-6 was a thin paste having a

specific gravity of 1.03, and, after thinning with water,

it was applied as a priming coat in treatment 21. Aquaplex Q-68 was a white pigmented paste, having a

specific gravity of 1.38 and was also thinned with water before using it. The water|)roofings were

applied with a paint brush, either singly, iu combina-

[19]
tion with each other, or with spar varnish, to dry walls

built of the cinder-concrete block n. Wall B256— 21n was given a priming coat made from

4 parts, by volume, of Aquaplex S-6 and parts of water. The amount of S-6 applied was equivalent to 140 ft^/gal of paste. The second and third coats applied to the wall on successive days after application

of the priming coat contained 4 parts, by volume, of Aquaplex Q-68 to 3 parts of water. The amounts of paste applied were equivalent to 360 and 540 ftVgal

for the second and third coats, respectively. Treatment 22, applied to wall B257-22ri, consisted

of two coats of Aquaplex Q-68 thinned with a volume

of water equal to that of the paste. The applications were made on successive days, and the amounts of paste used were equivalent to 180 and 380 ft^/gal for the first and second coats, respectively (90 and 217

ftVgal of paint). Treatment 23, applied to wall B258-23w, consisted

of one coat of spar varnish and two coats of Aquaplex

Q-68, each applied on successive days. The spar varnish met the requirements of Federal Specification

TT-U-121a and weighed 7.5 lb/gal. The amount of varnish applied was equivalent to 120 ft^/gal. The

Aquaplex Q-68 was thinned with water as for treat- ment 22, and the amounts of paste applied were 235 and 330 ftVgal, respectively, for the second and third coats (135 and 190 ft^/gal of thinned paint).

It required about 25 to 30 min to apply each coat of paint, and all the walls had been stored indoors for 6 months when they were tested for permeability.

The walls treated with Aquaplex were rated P or VP in the premeability tests made after treatment and also after exposure outdoors. The coatings were water repellent, but they contained many pinholes over the block and some larger openings over the

joints. They were not crazed or flaked after weathering outdoors for 14 months, but, when returned in- doors, they were dusting badly and contained many

rust spots from particles of iron in the block. Examination of the coatings during the weathering exposure

period disclosed the growth of black and pink fungi over small isolated areas on more than half of the

block. The walls were painted with the same technique used

to apply cement-water paint coatings, and special care was not taken to "touch up" and fill pinholes or larger

openings in an area that had been painted. It is possible that the coatings would have been more effective

if a stifi'er brush had been used, or if the paints had

been applied to units having a smoother surface

texture.

(b) Dricoat

Dricoat (waterproofing 24, table 15) was a white

pigmented waterproofing, manufactured by the BillingsChapin Co., New York, N. Y. The material was said

to be a waterproof sealer, for exterior or interior use, that could be applied as received to wet or to dry

surfaces. The instructions for use stated that the wall surface should be clean and that the waterproofing

should be kept well stirred and flowed onto the wall

surface with a brush as though it were a varnish and

not brushed out as for a paint.

Two applications of Dricoat were made with a paint

brush on successive days to the face of wall Blll-24(;c.

The wall was dry, and it required about 25 min. to apply

each coat. The average amounts of Dricoat applied were equivalent to 100 ftVgal for the first coat and

130 ftVgal for the second, about 57 ftVgal for both

coats. The wall was stored indoors and tested for permeability 6 weeks after treatment. When first tested, the treatment was water repellent, but after

1 day the applied water formed a continuous film over

the face. The wall was rated VP, the rate of leakage was high, and water penetrated to the back in less than

2 hr.

(c) Drye

Drye (waterproofing 25, table 15) was manufactured

by the Weather Seal Co., Cincinnati, Ohio. The

ingredients in the material were said to include iron

dust, chloride of lime, alum, and portland cement. The instructions for use were to mix to a thin consistency

with water and apply with a brush, with frequent

stirring. Two coats, to be applied on successive days, were recommended for waterproofing the outside face

of masonry walls. Wall B326-25cc was waterproofed with two treat- ments of Drye. The material was prepared for application by adding water to the dry powder until a thin paste of brushing consistency was prepared. The

amounts of added water, by weight of dry materials, were 60 percent for the first coat and 80 percent for the

second. The applications were made on successive days, and the amounts applied were equivalent to 35 lb of powder per 100 ft^ of wall area for the first coat and 6 lb for the second. The brick were highly

absorptive, and it is possible that more water should have been added to the waterproofing for the first treatment. The joint structure in the masonry could

still be observed after treatment, and the color of the

wall when dry was a dull, rusty brown interspersed

with small isolated areas of lighter or darker shades. The treatment with Drye was effective. The wall was rated G, and only 5 percent of the back of the wall was damp after an exposure of 1 day. When again

tested, after weathering outdoors for 17 months, the damp area on the back, at 1 day, was 60 percent, and

the wall was rated F. There was no water visible on

the back, and no leakage was observed from the flash- ings during the tests.

(d) Maure Brush Tex and Plaster Special

The Maure Corporation, New York, N. Y., sponsored

the construction and waterproofing of eight masonry

walls. One of these was waterproofed with Maure

Brush-Tex and one with Maure Plaster Special (waterproofings 26 and 27, table 15). The waterproofing and

testing of the other six walls, treated with Maure

Liquid Watei-proofing, will be discussed elsewhere in

[20]
this report, see section VII-2 (d). All of the materials were said to contain an emulsion of linseed oil and were recommended for use on either wet or dry masonry

surfaces. The application of the waterproofings was made under the direction of L. C. Maure. Maure Brush-Tex was a light-colored plastic paint

suitable for application with a brush. The material was thinned with a small amount of water, and the

specific gravity after thinning was 1.44. Two coats were applied, one immediately after the other, to wall B198-26m, using a 3}^-in. paint brush. The amounts

of thinned material applied for the first and second coats were equivalent to about 60 and 38 ft^/gal, respectively.

The total time required for treatment was 15 min.

The wall was stored indoors and tested for permeability

about 1 month after treatment. The data show that the treatment with Maure Brush-Tex was ineffective. The wall leaked badly, was penetrated to the back by

water in less than IJ^ hr, and was rated VP. The Maure Plaster Special was a pigmented waterproofing paste of troweling consistency that dried or set

to a hard finish after application. Two coats of Plaster

Special were applied with a plasterer's trowel to the exposed face of wall B103-27cc on successive days.

The suction of the highly absorptive brick in the wall was reduced by a thorough wetting, and the first coat of Plaster Special was applied, as received, the amount

used being equivalent to about 11 ft^/gal. The next day the first coat was slightly crazed before it was

wetted down and a second coat applied. The amount

applied for the second coat was equivalent to 67 ftVgal.

The wall was tested about 1 month after treatment. The Maure Plaster Special on wall B103 was effective when first applied, and the wall was rated E. This

wall was weathered outdoors for 2 years and again

tested. The top portion of the waterproofing was

severely cracked, and one small portion of it had

spalled. The cracks in the coating appeared to be

located over the mortar joints of the brick backing.

It is probable that damage to the coating of Plaster

Special was caused or aggravated by frost action in the

brick backing. Before being tested for permeability, the loose, spalled, portion of Plaster Special was re- moved and replaced by a coating of portland-cement

mortar. The wall was rated P in the permeability

test, and water penetrated to the inside face of the brick backing in less than 3 hr.

(e) Tymstone

Tymstone (waterproofing 28, table 15) was a pigmented, cementitious material containing magnesium

oxychloride cement. After tempering the Tymstone

powder with water, it was used as a mortar and as a

coating for masonry units. Tymstone Studio, Chicago,

111., sponsored the construction and waterproofing with

Tymstone of one wall built of Waylite concrete units. The wall, B303, was built in Chicago, and the method

of construction was said to be as follows: The faces of the Waylite block were dipped into Tymstone mortar, and the block were placed into positions in the wall.

The wall faces were then smoothed with a brush. 'J'he standard formulation for Tymstone mortar was used,

and it was claimed that it was dense enough to greatly retard the penetration of water but sufficiently porous

to permit the passage of vapor. A number of hard,

thin brick-tiles were bonded to a portion of the inside, unexposed face of the wall about 30 min. after the Waylite units were dipped into Tym.stone mortar. When received, the specimen contained seven courses

of Waylite block and was too great in height to he tested. W. A. Wilson, of the Ludowici Celadon Co., Washington, D. C, acting for the Tymstone Studio, removed

the top course of block and substituted a course of brick header units at the top and bottom of the wall. A special Tymstone mortar, known as Tymstone

Patching Cement, was tempered with water and used

to coat the brick before placing them in the wall. The

joints between the brick were about }i in. thick. The

wall was tested for permeability about 10 days after

its reconstruction. When tested for permeability, the Tymstone-coated

wall was rated E, and there was no penetration of water through the wall during an exposure period lasting 5 days. The Tymstone Patching Cement was hygroscopic and became sticky because of water absorbed

from the humid air during the test. Wall B303 was weathered outdoors for 18 months

and tested twice for permeability during the interval November 1940 to June 1942. At the end of the exposure period, the Tymstone coating was dusting badly,

and the joints between the Waylite units were plainly

discernible. The wall was rated E in both tests made

after the exposure periods (table 15).

(J) Varcraft Varcraft (waterproofing 29, table 15) was a white

pigmented oil-base paint made by the Varcraft Works,

Pottstown, Pa. Two coats of Varcraft were applied on

successive days, with a paint brush, to the exposed

faces of each of two concrete-block walls. The walls were dry when treated, and the paint was applied as

received, ready-mixed.

The amounts of paint used for the first and second

coats on wall B223-29m were equivalent to 145 and

270 ft^/gal, respectively. The amounts similarly applied

to wall B255-29n were equivalent to 95 and 150 ft-/gal. The walls were stored indoors and were tested for per- meability 11 months after being painted.

The Varcraft applied to the wall built of stone-concrete block (wall B223) reduced the rate of leakage

through the wall, which was rated P. The coatings

applied to a backing of cinder-concrete block (wall B255) were less effective, and this specimen was rated VP. The technique used in painting these walls was

similar to that used for applying cement-water paints

and Aquaplex (waterproofing 22, table 15). It is possible, that the treatments might have been more

effective if a stiffer brush had been used. After weathering outdoors for 1 year, the coating on wall B223 was dusting, and the permeabihty of the wall was again rated P.

[21]
(g) Discussion

The most effective and durable of the pigmented waterproofing materials were those

containing portland or magnesium oxychloride

cement. The treatments with Drye and Tymstone were rated 6 and E, respectively, and

were comparable in performance to cementwater paint coatings. A thick trowel coating

of Maure Plaster Special, containing an emulsion of linseed oil, was rated E when first applied. A thinner coating of a similar material (Brush-Tex), applied with a brush, was

ineffective. Brush coatings of emulsified resin or oil-base paints were rated VP or P, and

were much less eft'ective as waterproofing than were cement-water paint coatings.

Since the water was applied to the exposed

faces of the walls from a pipe with perforations

spaced on 1-in. centers, the permeability test was more favorable to water-repellent surfaces

than to those that wei*e readily wetted. The

applied water combined into rivulets on waterrepellent coatings and a large area was not

covered with water until the degree of repellency was reduced. Some coatings were still highly

water repellent after an exposure lasting 1 day.

2. Colorless Surface Coatings

The results obtained from the permeability

tests before and after treatment, and after outdoor exposure on walls treated on the ex- posed faces with colorless waterproofings, are described in table .16.

Tabi,e IB.

Permeability of walls treated wiih colorless proprietary surface coatings

Trade name Wall

AmprufCeremul-W.

Filporize.

Maure Liquid Waterproofing

Por-fllite_

Surten-R_

B109_

B116-

BUS.

Designation »

32cc

3266.

B244 34cc . B243 34cc B245 33m

B246 34m. ... B247 34m B248 34m _ _ .

B261.- - 35r. _ ... B267 35r B268 35r.

B107 36cc B112 36cc .. ... 3130 36m..

Condition of wall and period

of outiloor exposure

Before treatment

After treatment

Before treatment

After treatment

Dec. 1940 to Aug. 1941. Before treatment

After treatment Nov. 1940 to Aug. 1941 Before treatment

After treatment May 1941 to Aug. 1941 Additional treatment.

/Before treatment \After treatment

/Before treatment

\ After treatment

/Before treatment

\After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

(.After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

/After treatment

/Before treatment

1 After treatment

± 11116 liC

uamp"

ness on back

failure as i by ^

Water

iQicateu

from

ii3.siiing

Maxi mum

rate of leakage

per hour

Area damp in

1 day

Rating

hr hr hr Liters Percent

0.

1

0. 2 0.2 4S 100 VP

. 4 .5 1 29 95 VP

.3 .3 .6 73 85 VP

0 060 E

2. 1 2.3 1.5 6.9 VP

.09 .09 .3 51 100 VP

11 ±3 19 ±3 0 15 F

2 2.3 6 5.4 90 VP

. 1 . 15 .2 17 100 VP

3.6 5.7 15 ±6 .03 70 F

.35 .86 .4 6.1 95 VP

8 17 ±4 0 60 F

.02 .04 .2 61 100 VP

. 15 . 17 1 47 100 VP

.05 . 1 .25 31 95 VP

.08 .5 .9 15 100 VP

.05 .06 .2 87 100 VP

.3 .3 . 5 51 100 VP

.03 .05 .08 132 90 VP

. 1 .2 .3 8 90 VP

.04 .05 .07 141 90 i'p

.3 .55 .6 9 90 VP

.05 .05 .03 64 70 VP

. 1 . 1 . 15 16 75 VP

.03 .04 .04 63 75 VP

.08 . 1 .3 12 65 VP

.04 .85 2.6 75 p

.03 2.5 .9 60 F

3.6 1.8 1.4 25 p

6.2 0 15 G

.5 3.5 4 .25 75 F

.9 4.6 6.2 . 2 60 F

.02 .02 .3 43 95 VP

. 2 . 2 .85 22 90 VP

.06 . 1 .2 57 95 VP

. 2 . 2 .7 13 90 VP

.03 .03 . 1 10 75 VP

. 1 . 15 .4 5 85 VP

» The number designates the kind of waterproofing treatment, the letter designates the kind of units used in the backings.

b The uncertainty of the observation is given if it exceeds 10 percent of the total elapsed time. Dashes indicates no failure of the wall.

[22]
(a) Ampruj

This material (waterproofing 31, table 16) was a

clear, colorless liquid said to contain clilorinated rubber

in solution with benzol or liigh-flash-point naphtha.

It was manufactured by the American Waterj^roofing

Co., New York, N. Y. One coat of Ampruf was applied by G. F. Bowdish,

of the G. F. Muth Co., Washington, D. C. to the ex- posed face of wall B109-31cc. The wall was dry when

the material was applied with a 3!^-in. paint brush,

first to the bed joints, then to the brick, and finally to the head joints. The amount of Ampruf applied was

equivalent to 68 ft^/gal, but the suction of the higlily

absorptive brick c was not satisfied. The material was

not diluted before treatment and weiglied 7.2 lb/gal. The wall was tested for permeability 8 days after treatment. Water penetrated to the back of wall B109-31cc in 30 min, the maximum rate of flow was nearly 30 liters/hr and the wall was rated "VP," after treatment. The

face of the wall was water repellent when the test was

started, but was only slightly repellent after an exposure

lasting 1 day, at which time the rate of leakage was a maximum.

{b) Ceremul-W

Gargoyle Ceremul-W (waterproofing 32, table 16) was a milky-white emulsion of wax in water, colorless after drying, made by the Socony-Vacuum Oil Co., New York, N. Y. The wax content of the emulsion was

said to be 45 percent, half of which was a paraffin wax

with a melting point of 135° F, and the remainder was

a microcrystalline (amorphous) wax with a melting

point above 155° F. It was recommended that Ceremul-W be used without dilution when applied to walls built of very highly absorptive or porous units, and that a dilution of not more than 1 part of water to

1 of Ceremul-W be used on walls of medium- or of low-absorptive bricks. It was stated that only one

coating of the material need be applied to masonry

walls when they were either wet or dry, but it was not recommended that the walls be wetted before treat- ment. The specific gravity of Ceremul-W was about 0.9. Three brick walls were treated on the exposed faces with Ceremul-W. Two of these walls, 19-3266 and

A18-32CC, were 12 in. thick; the other, B116-32cc was

8 in. thick. All the walls were of workmanship B. They were dry and clean when treated. Wall B116, built of the highly-absorptive brick c, was

treated with undiluted Ceremul-W in 17 min. The

material was applied with a paint brush, and the amount used was equivalent to 154 ft^/gal. Wall A18 was also treated with undiluted Ceremul-W

in 17 min. The material was applied generously with

a paint brush (as though painting with a varnish) , and

the amount applied was equivalent to 156 ftr/gal. Wall 19, built of the medium-absorption brick h, was given two treatments of one coat each. The wall was tested for permeability after the first treatment,

then exposed outdoors, again tested, and tlieii dried before the second application. The Ceremul-W was

diluted with an equal volume of water for both treat- ments. The material was liberally applied to the

crevices in the joints of two cour.ses at a time, and then

it was brushed horizontally across the brick. 1'he first treatment required 13 min, and tlie amount of dihiterl material applied was equivalent to 185 ft'Vgai (370 ftV

gal of undiluted Ceremul-W). Although the wall had weathered outdoors for 8 months, the second

application was not absorbed as readily as the first, and the face of the wall appeared to be water repellent.

The waterproofing had to be "worked" into the joints

to prevent it from running down the face. The

second treatment required about twice as much time

and two-thirds as much material as the first. The

brick in wall 19 had a glossy appearance after treatment, but there was very little or no discoloration noted on any of the walls waterproofed with Ceremul-W.

The treatments with Ceremul-W were efl'ective when

first applied, particularly on the 12-in. wall A18, built

of brick c. The face of wall A 18 was still water repellent, and there was no dampness on the back of the

wall after an exposure lasting 5 days, and the wall was

rated E. There was some white discoloration in the

joints and on some of the brick at the end of the first day of test, but this disappeared when the surface of the wall had diied. The walls treated with Ceremul-W were again tested

after having weathered outdoors for 3 to 9 months. The

wall faces were still water repellent throughout the

tests, but the average rate of leakage was 6 liters/hr. The walls were rated VP. Wall 19 was treated for the second time, after it had been stored outdoors, and,

when tested, was again rated F. There was no leakage

from the flashings, but 60 percent of the back of the

wall was damp. It is not known if the permeability

tests (which were severe) or the weathering exposures were responsible for the loss in effectiveness of treatment

with Ceremul-W.

(c) Filporize

The Filporize (waterproofing 33, table 16) was a

colorless material manufactured by Stone & Murphy,

Inc., Middletown, Conn. Information on the label stated that Filporize was "A colorless liquid waterproofing that stretches, for application to brick, cement,

stucco, art stone, cut stone. Application should be made with a criss-cross motion with a full brush to a

clean, dry surface. For brick or concrete, use 200 to 250 ftVgal for the first coat and 300 to 400 ftVgal for the second coat. Allow 48 hr between coats." Two coats of Filporize were applied to the exposed

face of wall B113-33cc, the second application was made

2 days after the first. The wall was dry and application was made with a 4-in. paint brush. The amounts

of Filporize api^lied were equivalent to 123 ft- gal for the first coat and 111 ft^/gal for the second. The brick were highly absorptive, and it required about 14 min

to apply each coat. The M^all was stored indoors and

was tested for permeability 1 month after treatment.

5069.34°—43——4 [23]
There was no discoloration noted on the wall after treatment. Although the wall face was water repellent when the

test was started, water penetrated to the back of the

wall in 10 min; the rate of leakage was excessive, and the treatment was rated VP.

(d) Maure Liquid Waterproofing

Maure Liquid Waterproofing (waterproofing 34, table 16) had a milky appearance but dried clear and

colorless. The liquid had a specific gravity of 1, and was diluted with an equal amount of water before

use. Six walls, two of brick c, two of stone-concrete

block, and two of cinder-concrete block, were treated when dry. One wall of each kind of backing was given two coats, one applied immediately after the other,

and its companion specimen was given three coats. A whitewash brush (brush 2, fig. 3) was used to apply

the waterproofing, starting each coat at the top of the

wall, and care was taken in brushing to prevent the

liquid from foaming under the brush. The total amounts of thinned Liquid Waterproofing required for two and for three coats applied to walls built of the

highly absorptive brick c (B244 and B243) were,

respectively, equivalent to 48 and 45 ft^/gal. Similarly, the amounts applied to walls built of stone- concrete block (B245 and B246) were 66 and 57 ftVgal,

and those applied to walls of cinder-concrete block (B247 and B248) were 89 and 82 ftVgal. The walls were tested for permeability about 5 weeks after treat- ment.

All the treated walls were rated VP. The rate of leakage, after treatment, was greatest from walls of brick c and least from walls of stone-concrete block m. The walls were water repellent, and the application of two or of three coats of Liquid Waterproofing did not

result in a significant diff'erence in the permeability of the specimens.

(e) Por-fil-ite

Por-fil-ite, formula B, for brick masonry (waterproofing 35, table 16) was a colorless liquid having a

specific gravity of 0.82. The material was made by

International Chemicals, Inc., Washington, D. C, and

two coats were applied with a paint brush to the exposed faces of three walls, B261, B267, and B268,

built of Munlock brick (brick r, table 1). The walls were dry when treated, and the applications to each

wall were made on successive days, under the direction

of T. K. McPherson. The waterproofing was applied

first to the head joints and then to the brick and bed

joints. The applications were liberal, and the surfaces

of the brick and mortar joints appeared to be nearly

saturated. The average amounts of Por-fil-ite applied

for the first and second coats were equivalent to 350

and 370 ft^/gal, respectively. The walls were tested

for permeability about 2 months after being waterproofed.

The walls of Munlock brick were rated P ov F before treatment, and were not as permeable as walls built of

concrete block or of brick c. The treatments with

Por-fil-ite significantly reduced the permeabilities of the specimens, which were rated F or G. (The tests do not indicate how effective the waterproofing would

be if applied to walls that leaked badly and that were

rated VP before treatment.)

(/) Snr-Ten-R

Sur-Ten-R was a milky-white emulsion of wax in water (waterproofing 36, table 16) manufactured by

Pal-Verd Inc., Chicago, 111., under license from the

Institute of Paper Chemistry, Appleton, Wis. It was

stated that the material was clear and colorless, when

dry, and that it contained 30 percent of waxes having

a melting point of 122° F or more. Pal-Verd Inc. sponsored the construction and waterproofing of three specimens. The walls were dry when treated on the exposed face with Sur-Ten-R, under the direction of C. L. Burnham.

Sur-Ten-R was mixed with an equal volume of warm

water (104° F) and then applied with a paint brush to wall B107-36cc, built of highly absorptive brick. After

the wall was given one brush coat, a small amount,

5 oz, of undiluted Sur-Ten-R was immediately brushed

on the joints. The material applied to the joints was

not readily absorbed by the masonry, and a white dis- coloration was left on portions of the brick near the

joints after the waterproofing had dried on the wall. The weight per gal of the diluted material was 8.2 lb, and the total amount of undiluted Sur-Ten-R applied was equivalent to 127 ftVgal.

Wall B112-36cc was given a brush coating of a solution containing 2 parts of Sur-Ten-R and 1 part of warm water (116° F). The time required to apply

the solution with a paint brush was 4 min. The joints

in the wall were then immediately painted with about

5 oz of undiluted Sur-Ten-R in about 9 min. The

total amount of undiluted Sur-Ten-R applied was

equivalent to 105 ftVgal. After drying the wall, portions of the brick near the joints showed a white

discoloration, as was also noted for wall B107. Wall B 130-3671 (built of cinder-concrete block) was

treated with one coat of Sur-Ten-R diluted with an

equal volume of water. A hand-operated, pressure- type spray gun, designed for spraying liquid insecticides, was used for 30 min to apply the waterproofing,

and the surfaces of the concrete block appeared to be

saturated. The amount of undiluted Sur-Ten-R applied was equivalent to 208 ftVgal. The wall showed

no discoloration after the waterproofing had dried. The brick walls B107 and B112 were tested for permeability 9 days after treatment, wall B130 was tested about 3 weeks after treatment. The treatments with Sur-Ten-R were ineffective, and the performances of the walls were rated VP. The faces of the walls were water repellent throughout

the tests, and white discolorations became more prominent over the brick and the joints within an hour after the tests were started. When the walls were stored

[24]
indoors for a few weeks, after the tests, a growth of green mold developed on the treated faces.

(g) Discussion

The colorless waterproofings, with the exception of Gargoyle Ceremul-W, were ineffective as waterproofings when applied to walls with high

rates of leakage, and such walls were rated VP,

both before and after treatment. Two walls

coated with Ceremul-W were rated F and one was rated E after treatment. When again

tested after weathering outdoors, these walls were rated VP. Walls of brick r treated with

Por-fil-ite, were rated P or F before treatment,

and the effectiveness of Por-fil-ite, when applied

to walls rated VP, was not determined. The

tests described in BMS 7 and BMS 76 show that

treatments with solutions containing 10 per- cent of paraffin and 5 percent of tung oil in mineral spirits were also ineffective. The

coatings of a paraffin and tung-oil wax, applied

to the joints of brick walls, were unsightly,

and were ineffective as waterprooffngs after an

exposure outdoors of 1 year. The data indicate that the only effective and

durable methods of waterproofing biick walls

without changing their appearance is hy cutting

out and repointing the joints with mortar or by brushing a pox'tland-cement gi'out into the

joints. The grout may contain 1 part of cement

to about l}i parts of fine sand, and it should be

applied to the dampened joints with a stiff brush. If the brick texture is smooth, excess grout may be easily cleaned from the imits with

a damp sponge.

Test walls with repointed joints were found

to be less permeable after outdoor weathering

than before, whereas the pei-meability of walls

with grouted joints was found to be slightly,

but not seriously, increased after exposure.

While repointing or grouting are effective treat- ments for the joints in brick walls, it may be

necessary, to also apply a water-repellent

(colorless) waterproofing to underburned,

highly absorptive brick; the water repellent,

if used, should be applied after grouting or

repointuig.

VIII. LARSON PRE-FORMED WATERPROOFING UNITS

1. Construction of the Specimens

The Brisk Waterproofing Co., New York, N. Y., sponsored the construction of ten 13-in. brick masonry

walls, of which 6 contained the Larson Pre-formed

Waterproofing Units, waterproofing 37, table 17. The waterproofing units were made of heavy asphaltimpregnated felt or paper dusted with mica. They

were preformed to fit the brick and course dimensions,

and were lapped and sealed at the ends to form a

series of waterproof membranes, as shown in figures 4,

5, 6, and 7. The vertical joints between the units were lapped 4 in. and sealed with an asphalt plastic cement of troweling consistency, which contained cut- back asphalt and asbestos fiber. The walls were laid

in common American bond, starting with three

stretcher courses. They were constructed in two

groups, diff'ering from each other in the extent and

method of filling the interior of the vertical joints

with mortar. The membrane waterproofings, placed

in some of the walls of each group, were similar. The bed joints in the first group of walls were fur- rowed, and the collar joints were open. The head

joints were buttered as in workmanship B (described in BMS82), except that the buttering was heavier, and

mortar was also placed in the head joints of the center

tier, or wythe. The bottom edge of the bottom membrane in the waterproofed walls was sealed to the copper

flashing, and the upper edge extended one course above

and one tier behind the bottom of the next membrane

above. The construction of the walls was begun at the back by laying the second and third tiers to the height

of the header courses. The backs of the membranes

were daubed with spots of plastic cement to bond them

to the vertical faces of the masonry. A mortar bed was placed on the horizontal surfaces of the membranes,

and the plastic cement at the joints was lightly coated with mortar. Joints in the wall faces were cut. The

sequence for laying courses and tiers was the same for the

plain and waterproofed walls in both groups. The

bricks were laid in mortar 2, and the average absorption

during partial immersion of the brick s in the first group of walls was nearly 70 g (table 1). The bed joints in the walls of the second group were

furrowed. The head joints in the facing tier were filled solidly with mortar; those in the center and backing

tiers were buttered. The face of the backing tier was

parged. The collar joint between the facing and center

tiers was filled with mortar by heavily buttering the

sides of the brick and by slushing from above. Xo

mortar was placed between the membrane, if used, and

the vertical face of the center tier. The suction of the

brick was nearly 40 g (table 1). The face joints were

cut flush, and weep holes were made in the lower portions

of the bed joints in the second stretcher course of the

facing. The holes did not extend past the first collar joint and did not penetrate the membrane.

[25]
Figure 4. —Wall B236 during consinniiun. The lower membrane is bonded to the copper flashing.

2. Effectiveness and Durability

The plain (not waterproofed) walls of group 1 were more permeable than those containing the

membrane waterproofing, but the performances

of the waterproofed specimens were disappointing. The sponsors had specified a highly

permeable type of workmanship, and water

penetrated the backs of walls B235 and B239 at or below the inner header courses in 30 min or

less. The data indicate that leakage entered

the facings faster than it leaked out at lower

elevations, so that water flowed over the tops

of the membranes. The air pressure maintained against the face of the wall was equivalent to a head of 2 in. of water, and the membranes were lapped a single brick course. The

Brisk Waterproofing Co. recommends, in practice, that weep holes be placed in the facings at the bottom of walls waterproofed with Larson

miits. Weep holes were therefore cut in the

head joints of the second or thu-d courses from

the bottom of the waterproofed walls. The

weep holes eft'ectively drained the collar joint of wall B236, and the wall was rated O histead of VP. It is probable that mortar in the collar

[26]
Figure 5.

Brick wall containing membrane

waterproofing.

Brick Waterproofing Co., series 1.

joints of the other walls prevented the weep

holes m them from functioning.

The walls of the second series were of a less permeable construction than those of the first, and the plain specimens, buQt without the membranes, were rated P. All the walls contained

weep holes at the bottom of the facing tiers. Waterproofed walls B263 and B265 were

rated E. Wlien again tested, after plugging the

weep holes, wall B263 was rated G, and wall

B265 was again rated E.

The walls were weathered outdoors for 30

months and, when again tested, the weathering- was found to have had no significant effect on

permeability.

The tests on the walls sponsored by the Brisk

Waterproofing Co. showed the importance of

adequate drainage through weep holes at the

bottoms of highly permeable facmgs in walls

contaming membranes. The Brisk Waterproofing Co. states that none of its mstallations

along the Atlantic Seaboard that were in the

path of the hurricane of September 1938 showed

any indication of leakage. They fm-ther pomt

out that the air pressure on a building wall may

fluctuate considerably during a storm. It is possible that, if the facings of the walls in series

1 had been less permeable, or if the au- pressure on the test walls had fluctuated between 0 and

10 Ib/ft^, the water penetrating the facings

would have drained to the outside and would

not have overtopi^ed the nacmbranes.

27

I
Figure 6.

Brick wall during construction, series 2.

Tab],!-; 17. I-^j!< < I n cness of Larson J 'rc-foriiicl Waterproofing Units

Time to failure as indicated by—>> Maximum

rate of leakage per hour

Area damp

in 1 day

Wall Designation » Condition of wall and period of outdoor exposure Dampness

on back

Water

on

back

Leakage

from

flashing

Rating

WALLS OF GROUP 1

B237..

B238..

B235..

B239_.

B240_

B236..

s37«.

S37ss37«-_

Not waterproofed _ .

.

do /Without weep holes- \With weep holes (Without weep holes^ \With weep holes /Without weep holes. Iwith weep holes /Without weep holes. /With weep holes

Ar.0.3

.2

.2

.3

.3.3 10±3

1.7

2. 2 63

hr.0.3

.2

.6

.6

.3

.3

0.3

.3.25

.5

1.2 0.7

53

Liters 3399

194.5

14

150

0

110.2

Percent

80

2560

60

65

65

4

10

150

VP

TP

VP

P

rp

VP

G

0VP

G WALLS OF GROUP 2 B264

tt B266

tt B263

tsit

B265.. t37t

/Not waterproofed

/Sept. 1939 to May 1942. /Not waterproofed

/Sept. 1939 to May 1942. {Waterproofed

Weep holes plugged

Oct. 1939 to May 1942.. {Waterproofed

Weep holes plugged

Oct. 1939 to May 1942..

0.08

.05

.04 .03

3.5

0.08

.05 .09

.04

0. 35

.35

.1.1

0.07

20.4

2.2 0

00

0

0

0

100

95 10090

0

250

0

0

0

P

P

P

P

E

aE

E

E

E

• The number designates the kind of waterproofing treatment, the letter designates the kind of units used in the walls.

b The uncertainty of the observation is given if it exceeds 10 percent of the total elapsed time. Dashes indicate no failure of the wall.

[28]
FiGURK 7.

Brick wall, series 2. Note weep holes in facing.

IX. WATERPROOFING APPLIED TO THE

UNEXPOSED FACES OF THE WALLS

Waterproofings applied to the backs (unexposed, faces) of the walls covered the edges of the end and top pargings, but they were not

applied to those portions of the walls between

the upper and lower flashings (fig. 1). Most of the walls were built of the highlyabsorptive brick c, and all were selected on the

basis of tests made before treatment as having

a maximum of leakage from the upper rather

than the lower flashings. The walls were diy

when treated, imless otherwise noted.

1. Bituminous Coatings

Bituminous coatings are often used as dampproofings or as waterproofings on the iaside

faces of masonry walls above gi-ade. The materials used in the coatings applied to the test walls were purchased in the open market and

under Federal specification, wherever applicable. The data obtained from tests made before and after treatment are given ui table 18.

[29]
Table 18.

Permeability of walls waterproofed on the backs, unexposed faces

Designation »

Condition of wall and

Time to failure as indicated by b— Maxi- mum Area Kind of waterproofing Wall period of outdoor

exposure Dampness on

back

"Water on back

Leakage from

flashings

rate of leakage

per hour idamp in

1 day

Rating

BITUMINOUS COATINGS

Asphalt

Coal tar

Asphalt roof coating AsphaJt emulsion Bituminous plastic cement

B97 B92

B66

B93

ceil.

cc42

cc43

cc44

ccib

/Before treatment,

lAfter treatment-

.

/Before treatment. lAfter treatment-. /Before treatment

\After treatment-. /Before treatment

lAfter treatment-. /Before treatment

(After treatment-.

hr

0. 01

. 5.07

.2

. 15

.3.06

2. 2

0. 03

1.6

hr

0. 02

. 5

. 1

. 2.35

.3.08 3.5

0.1 1.6

hr0.3

.9

.3.3.35

. 4.25

1.7

0. 26

6

Liters Percent

54 95 VP

1.

1

40 P

60 90 VP

29 80 VP

64 95 VP

39 95 VP

51 95 VP

2.6 80 P

58 95 VP

34 30 VP

CEMENTITIOUS COATINGS

Portland-cement and sand brush

coating.

Iron-dust brush coating (iron dust and salammoniac). Portland-cement and iron-dust brush coating.

Portland-cement, iron-dust, and

sand trowel coatings.

Mortar parging

.

Ibios BlOO

BlOI

|B102

1b104

cc51.

cc51

cc52

cc53

cc54

cc54

cc55

/Before treatment

lAfter treatment

fBefore treatment

\After treatment

/Before treatment

1 After treatment

/Before treatment

\After treatment

(Before treatment Mfter treatment

[Apr. 1940 to Aug. 1941_. (Before treatment

(After treatment

[Mar. 1940 to Aug. 1941

.

(Before treatment

K After treatment

[July 1939 to Aug. 1941-

.

0.1 0.2 0.2 46 96 VP

.35 15±6 0. 07 36 F

. 1 . 1 0.3 55 95 VP

. 1 . 2 4.0 0.6 95 P

.07 .08 0.3 48 100 VP

. 1 . 1 .3 16 90 VP

.04 .04 .3 49 95 VP

.1 .25 .65 0.4 95 p

.1 . 1 .3 44 95 VP

.75 0 8 E

.4 0

36

15 E

.08 .09 .4 100 VP

.4 0 8 6

1.0 10 0.2 10 F

0. 07 . 1 0. 26 46 100 VP

0 30 G

.3 5 0 45 F PROPRIETARY MATERIALS

Armor CoatDricoat

jB304 _ 7i56 1b305 m56

B106 cc24

/Before treatment

(After treatment-. /Before treatment

(After treatment-. /Before treatment

(After treatment-.

0. 03 0. 05 0. 07 30 90 VP

.7 .7 0 20 P

.02 .03 .1 30 90 VP

2. 6 2.6 0 25 P

0. 07 0.08 .2 31 95 VP

.3 .3 .3 6 80 VP

» The number designates the kind of waterproofing treatment, the letter designates the kind of units used in the walls.

i> The uncertainty of the observation is given if it exceeds 10 percent of the total elapsed time. Dashes indicate no failure of the wall.

" Rate of flow from upper flashing only.

(a) Asphalt

One coat of a primer and one coat of hot

asphalt (waterproofing 41, table IS) were applied to the back of wall B96-cc41. The primer

and the asphalt met the respective requirements

of Federal Specifications SS-A-701 and SS-A666, type 3. The amount of primer used was

5.7 lb /1 00 ft^ of wall area, and the wall was

primed 2 days before the asphalt was applied.

The asphalt was smoking hot when applied to the wall with an enamel daubing brush. The

asphalt did not adhere well to the brush, and

there was considerable waste during application. After the first coat had been brushed on

the wall, additional asphalt was applied to many

areas that did not appear to be properly coated.

The brick mason who applied the asphalt

stated that he would have preferred a mop to the

daubing brush for the purpose. The coating was about 1/16 in. thick, and the amount of asphalt applied was about 47 lb/100 ft^. The

wall was tested for permeability 2 weeks after

it was waterproofed.

It required about 15 min. after starting the

test for wall B96 to become sufficiently wet, so that some of the applied water ran off the ex- posed face of the wall at the bottom. Leaks

appeared in the asphalt coating above the upper

flashing in about 30 min, but the maximum rate

of leakage thi'ough the coating (1.1 liters/hr) was observed after an exposure period of 1 day.

At that time, about 15 large blisters 1 to 2 in. in diameter and about 30 small blisters % in. in

[30]
diameter were observed in the coating. Most of

the blisters were located over the brick and

many had collapsed, permitting a flow of water

from them to the upper flashing. It is probable that water penetrating the masonry at the

joints had formed blisters in the coating at the

points of weakest bond, on the smooth-textured surfaces of the brick. The performance

of the wall was rated P.

(b) Coal Tar

One coat of a primer and one coat of hot tar (waterproofing 42, table 18) were applied to the

back of the wall B97-cc42. The primer

(creosote oil), met the requirements of Federal

Specification TT-W-561a, and was applied

with a paint brush. The amount of primer

applied was 5.9 lb/100 ft^. Two days after priming the wall, the hot coal tar was applied

with the same type of brush used to apply the

hot-asphalt coating to wall B96. The tar dripped from the brush, but it was applied to the wall with less difficulty than was the asphalt.

The thickness of coating was Ke to Ys in., and

the amount applied was 56 lb/100 ft ^ of wall

area. The coal tar met the requirements of Federal Specification R-P-381, type II. The

wall was tested for permeability 3 weeks after it was waterproofed.

The coal-tar coating, applied to wall B97, was more permeable than the asphalt coating applied to a similar specimen and was rated VP.

The first leak in the coating occurred in 12 min

over the center of a header brick in the second

header course from the bottom. The second

leak was noted over a head joint in the first header course. The rate of leakage (from the

upper flashing) was a maximum of 29 liter/hr

after an exposure period of 1 day. At that

time the lower two-thirds of the coating was

wet and covered with blisters.

(c) Asphalt roof coating

One coat of an asphalt roof coating of brushing consistency (waterproofing 43, table 18) was

applied to wall B92-cc43. The trade name of the roof coating was Sure Seal, and it was made

by the Lasting Products Co., Baltimore, Md.

The material was said to be 100-percent pure

asphalt and asbestos, and it met the requirement-s of Federal Specification SS-R-451,

except that the slippage and flow at 140° F, on

metal and prepared roofing, was a maximum of

2)4 in., exceeding the permissible maximum.

The material was applicnl to the back of the

wall with a whitewash brush (brush 2, fig. 3),

and the amount applied was 16.5 lb/100 ft^. The wall was tested for permeability 6 weeks

after it was waterproofed.

The wall was rated VP. Leaks in the coating

appeared first over the joints in the second

header course in 0.3 hr and later over the brick.

The rate of leakage was a maximum of 39

liters/hr at the end of 1 day. The back of the

wall was wet and blisters }^ to in. in diameter

had formed over each brick. There were no

blisters over the joints.

(d) Asphalt Emulsion

An asphalt emulsion of troweling consistency

(waterproofing 44, table 18), known as GorocoAquaseal, made by the Armstrong Cork

Products Co., Lancaster, Pa., was applied to

to wall B66-cc44. The emulsion contained

asphalt, clay, and water but did not contain

fibers. It was recommended for use as a

protective coating for concrete, metal, or saturated felt. There was no Federal specification applicable to this material.

A coating Ke to % in. thick was applied to the back of the wall with a plastering trowel;

the amount applied was 66 lb/100 ft' of wall

area. The wall was tested for permeability 2 months later. About 50 blisters up to 1 in. in diameter were found on the back of the wall after an

exposure of 1 day, and water leaked through

many of them that had broken. The wall was

rated P.

(e) Bituminous plastic cement

One coat of a bituminous plastic cement of trowelmg consistency (waterproofing 45, table

18) was applied to the back of wall B93-cc45.

The material, known as Ruberoid Plastic

Cement, was made by the Ruberoid Co.,

Baltimore, Md., and it met the requirements of Federal Specification SS-C-153, type I, as- phaltic base.

When applied to the wall, Ruberoid Plastic

Cement pulled away from the masomy at a

[31]
Figure 8.

Back of wall BOS, about 5 hours after start of test. The wall was treated on the back with bituminous plastic cement.

few joints, and it required careful troweling to coat the wall. The amount applied was about

110 lb/100 W of wall area. The thickness of

the coating was about }i in., and the wall was

tested for permeability 2 months after treat- ment.

Large blisters formed at and below the second

header course from the bottom of the wall and

at the lower-right portion of the wall in about

4 or 5 hr, as shown m figure 8. The large

blister in the lower-right portion of the photograph broke at the flashing in 5}^ hr. The

maximum rate of leakage from the upper

flashing was 34 liters/hr at 1 day, and the wall was rated VP.

(/) Discussion

None of the bituminous coatings applied to the back of the walls was rated better than P.

The coatings were more or less blistered after an

[32]
exposure of 1 day, and it is probable that continued or repeated exposure would seriously

damage them and still further increase their

permeability. The backs of the walls were not

plastered, and it was not determined if plaster

would have prevented the formation and en- largement of blisters in the bituminous coatings. It is probable, however, that a plaster

coating would not have prevented damage to the bond between the waterproofing and the

inside faces of the test walls. The data indicate

that bituminous coatings are of little benefit as waterproofings on the inside faces of walls that

leak badly.

2. Coatings of Cementitious or of

Proprietary Materials

The materials used in the cementitious coatings were portland cement, Potomac River

building sand, iron dust (iron powder and sal ammoniac), and hydrated lime. They were

used singly or in combination and were tempered with water to a brushing (grout) or to a

troweling (mortar) consistency. The building

sand, except for that used in a mortar parging, was screened through a No. 16 sieve. A sieve

analysis of the screened sand is given in table 19.

Table 19.Sieve analysis of screened Potomac River

building sand^

U. S. standard Sieve number

Percentage by weight

of sand

passing

16 Percent

100

7120

3

30 -. 50100

» Potomac River building sand screened through No. 16 sieve.

(a) Poriland-Cement and Sand Brush Coating

Two coats of a cement-sand grout (waterproofing 51, table 18) were applied to each of

two walls, wall B98 and Bl08-cc51. The proportions of the grout, by weight, were 1 part of

Portland cement to 2 parts of dry sand screened

through a No. 16 sieve. The amount of water

added was 27 percent, by weight, of the dry

materials. The walls were wetted thoroughly,

but there was no water visible on the masonry

when the two coatings were applied to the walls

on successive days, using a roofing brush

(brush 4, fig. 3). A considerable portion of the

larger sand particles dropped from the walls,

especially during application of the first coats,

and the proportion of cement in the gi-out re- maining on the wall was probably larger than is indicated. The first coats were wetted lightly

before the second ones were applied. The grout was frequently stirred during its application,

and the amounts applied were approximately

equal for each coat. The amounts of cement

used for both coats were 2.3.5 and 24.4 lb/100 ft^ of wall area for walls B98 and BIOS, respectively.

The amount of cement used was slightly greater

in weight than the average weight of the dry

powder required for the coatings of cementwater paints applied to similar walls. The

walls were wetted twice daily for 3 days and were

tested for permeability about 3 months after treatment. Walls B98 and B108 were rated F and P,

respectively, after treatment, and the rate of

leakage through the walls was reduced fi-om an

average of about 50 to less than.l liter/hi-.

(6) Iron-Dust {Iron Powder and Sal Ammoniac)

Brush Coating

Two brush coats of iron dust and sal ammoniac (waterproofing 52, table 18) were applied to wall Bl00-(;c52. The wall was thoroughly

wetted before each treatment, but it was allowed

to dry until no water was visible on the back

when the coatings were applied. The waterproofing was Euco brand ii-on waterproofing

made by the Euclid Chemical Co., Cleveland,

Ohio . The material was mixed to a heavy-paint

consistency by adding l)i parts of water by

weight to 1 part of Euco, and it was kept well

stirred during application. The two applications were made 2 days apart with a paint brush.

The waterproofing was applied first to the joints

in the wall and then to the brick. The water

in the mixture was readily absorbed by the

brick, and the color of the wall, after treatment, was mottled with different shades of brown.

The amounts of Euco used for the fii-st and

second coats were, respecitvely, 8.1 and 7.0

lb/ 100 ft^ of wall area. The wall was wetted

twice daily, 1 day after the first coat, and 3 days

after the second coat was applied. It was

[33]
tested for permeability about 4 months after treatment.

Water penetrated the coating at the header

courses in less than 10 min, the maximum rate

of flow was 16 liters/hr, and the wall was

rated VP.

(c) Portland-cement and iron-dust brush coatings

Two brush coats of portland cement mixed

with iron powder and salammoniac (waterproofing 53, table 18) were applied to wall

Bl01-fc53. The waterproofing was mixed in

the proportions, by weight, of 10 percent of Euco brand iron waterproofing and 90 percent

of Portland cement. The dry mixture was then

tempered with 38 percent of water, by weight,

to the consistency of a grout or a thick paint.

The wall was wet, but there was no water

visible on the surface when two applications of the grout were made, 2 days apart, with a brush. The amounts of cement applied for the first and second coats were, respectively,

32.8 and 14.1 lb/100 ft^ of wall area. The

wall was wetted twice daily for 3 days after the

second treatment, and the treated surface was

mottled in shades of brown. The permeability

of the specimen was tested about 4 months

after treatment.

Water became visible on the coating behind

the second header course in 15 min and the

rate of leakage reached a maximum of 0.4

litei'/hr in about 6 hr. The wall was rated P.

(d) Portland-cement, iron-dust, and sand trowel

coatings

Wall Bl02~cc54 was treated with two trowel

coatings of a portland cement and sand mixture containing Euco brand iron dust and sal- ammoniac. The proportions used were 1 :0. 1 1 :2 parts, by weight, of cement, Euco, and dry sand,

passing a No. 16 sieve; the amount of water

added was 18 percent, by weight, of the dry

materials. The first coat was applied with a

steel plastering trowel, and, although the brick

backing had been thoroughly wetted, the suction of the backing removed so much water

from the mortar that it was troweled with a wooden float after a short period of time.

Two days later the mortar covering was wetted

and the second coat applied. The thicknesses

of the first and second coats were 0.25 and 0.3

in., respectively, and the amounts of cement

applied were respectively equivalent to 87 and

113 lb/100 ft^ of wall area. The wall was

stored in air having a relative humidity of 85

percent for 5 days, and it was tested for per- meability 4 months after treatment. A similar treatment, consisting of one brush

and two trowel coats, was applied to wall

Bl04-cc54. The proportions of the grout and

plaster were, respectively, 1:0.11:1 and 1:0.11:2

parts, by weight, of cement, Euco, and dry sand

passing a No. 16 sieve. The water contents

were, respectively, 36 and 17 percent, by weight,

of the dry materials. The brush coat was

applied to the wetted surface with a whitewash brush, and it was followed almost immediately, while the grout was damp, with the

first trowel coat. This trowel coat was scratched

and 2 days later, after wetting, the second

trowel coat was applied. The trowel coats were

not rodded and were a total of about 0.9

in. in thickness. The amounts of cement applied for the brush coat, the first and second

trowel coats were, respectively, 12, 175, and

155 lb/100 ft^ of wall area. The walls (B102

and B104) were given a preliminary conditioning exposure lasting 2 days and were dried

before being tested for record.

The treatments were highly effective, and

the walls were rated G or E. When again tested, after having been weathered outdoors for 16

months, walls B102 and B104 were rated E

and F, respectively. Both walls were damp in vertical strips at the ends, where the waterproofing covered the pargings on the masonry.

A small leak (0.2 liter/per hr) from cracks in the

coating over the right parging on wall B104

reduced the rating of this wall from G or E

to F.

(e) Mortar parging

One trowel coat of a mortar parging (waterproofing 55, table 18) was applied to wall

B68-cc55. The mortar (mortar 1, table 3) had

a water content of 18 percent, by weight, of dry

materials. The wall was wetted thoroughly

and the mortar parging was placed to a depth of 0.43 in. with a steel plasterering trowel. The

amount of cement applied was 105 lb/100 ft^ of

wall area. The wall was wetted twice daily for

[34]
3 days. It was tested 7 weeks after treatment,

but was not given a preliminary conditioning

test.Moisture (dampness) penetrated the wall in two vertical belts at the ends, but there was

no leakage from the upper flashing, and no

water was visible on the back at the end of 1 day. Since only 30 percent of the wall area was damp in 1 day, the wall was rated 0. When

again tested after having been exposed outdoors

for 2 yr, water became visible on the back over

the first header course in 5 hr, and the wall was rated F.

ij) Armor Coat

Armor Coat (waterproofing 56, table 13) was a white

pigmented cementitious powder, manufactured by

Armor Laboratories, Glendale, Calif. The makers

sponsored the construction and waterproofing of two

8-in walls, one of stone and the other of cinder-concrete

block. The dry walls were prepared for painting by scraping

loose bits of mortar and some efflorescent salts from the back with a putty knife. The backs were then thor- oughly wetted, and application of the paint was begun

when water was no longer visible on the masonry. The

paint was prepared by mixing 10 parts, by weight, of Armor Coat with 8.2 parts of water.^ A small portion

of the water was slowly added to the powder, with

constant stirring until a paste was formed. Fifteen minutes later the remainder of the water was stirred into the paste, and the paint was ready for use about

20 min after final mixing. Two applications of paint were made to each wall with a paint brush on successive days by G. W. Ketch. About 50 g of a

paste made from Armor Coat, white silica sand passing

a No. 50 sieve, and water was rubbed into the joints of each wall, and the walls were lightly wetted before the second coat was applied. The amounts of dry powder

used in the first and second paint coats on wall B304-

?i56 (cinder-concrete block) were respectively, equivalent to 8.6 and 3.5 lb/100 ft^. Similarly, the amounts

of powder applied to wall B305—m56 (stone-concrete

block) were 9.8 and 3.2 lb/100 ft2. The walls were

wetted once a day for 2 days, and were stored indoors

for 3 weeks before they were tested for permeability.

Small drops of water penetrated pinholes in the .\rmor Coat on the first course of cinder-concrete block

of wall B304 (table 18) in 0.7 hr. A similar failure occurred in the coating on the first course of stone- concrete block of wall B304 in 2}^ hr. The leakage

from pinholes in the coatings was small and was not

' The instructions issued by the .\rmor Laboratories, Inc., for the appli- cation of two coats of Armor Coat include a recommendation that the first coat be of thinner consistency than the second. "Two Coat Jobs: First

coat, 1 part Armor Coat to IH parts water; second coat, 1 part Armor Coat

to IH parts water or in equal proportions by volume."

enough to promote a sigiuficant flow of water, .\fler an exposure of 1 day, drops of water were si ill visible on the lower half of the walls and both were rated P.

(g) Dricoat

Dricoat, a white pigmented waterproofing with the consistency of a jjaint, is described in section VII-1 (b). Two applications of Dricoat were made on succe.ssive days to the back of wall B106-(c24. The amounts

applied were approximately equivalent to 100 and 130

ft^/gal for the first and second coats, respectively. Water penetrated the coating behind a head joint in the fir.st header course in 18 min. The wall was rated VP, and the maximum rate of flow of 6 liters/hr was

observed after 7 hr of exposure.

(h) Discussion

Cementitious materials are in general use for waterproofing the inside faces of basement

walls, but they are not as widely used as bituminous coatings for waterproofing the backs of walls above grade. Walls below grade may be

subjected to a head of several feet, rather than

inches, of water, and the permeability test described in this paper is not readily applicable

for measuring the effectiveness of waterproofings for such walls. The data and wall

ratings obtained from the tests on cementitious

coatings applied to the backs of the walls are

of principal value in comparing the effective- ness of these coatings with the other waterproofings that were tested, and which were

intended for use on walls above grade. Since

basement rooms are not usually used as living

quarters imless the plaster or other interior

finish is furred from the wall, the occasional

penetration of water which does not develop

into leakage may not be objectionable. It is probable, therefore, that the waterproofing

treatments rated as 6 or E in table 18 may be

satisfactory for use on basement walls. None of the brush coatings of cementitious or

of proprietary materials was rated better than

F. Trowel coatings of portland cement and

sand, mi.xed with or without admixtures of powdered iron and salammoniac, were applied

to three walls and were rated 6 or E. Although two of these waUs were significantly more permeable after weathering outdooi's than

before, it should be noted that the walls were

stored outdoors without protection, and the

[35]
exposure was more severe than if the coatings

had been apphed to the inside faces of building

walls. X. CONCLUSIONS

The following pertains to the effectiveness

and durability of the cement-water paints and

of the other waterproofings applied to the

small, highly permeable walls built of bricks or

of concrete blocks. The waterproofed speci- mens were tested under conditions simulating

wind-driven rain. The durability of the most

effective treatments was measured by comparing the permeability of the specimens before

and after outdoor weathering exposure.

1. Cement-Water Paints

(a) Two coats of cement-water paints applied to the exposed faces of masonry walls were

highly effective as waterproofings. Although

weather-stained after an exposure outdoors of

1 or 2 years, many of the paint coatings were found to be less permeable after exposure than

before.

(b) The paints were more easily applied to walls of rugged-textured units (cinder-concrete

block) with stiff brushes (fender-cleaning brush)

than with soft brushes (whitewash brush) . The

coatings were less permeable and contained

fewer pinholes when applied with a stiff brush.

A roofing brush, intermediate in stiffness between a fender-cleaning and a whitewash brush, was effective for use on walls of smooth-textured

brick.

(c) Cement-water paint coatings for walls of

rough-textured units reached a maximum of

eft'ectiveness and durability when fine sand was

added to the paint used for the first coat. The

sanded paint filled depressions in the surfaces

of the units and sealed small openings in the

joints, so that the second coat of paint (prepared

without sand) was easily applied.

(d) Coatings applied to dry highly-absorptive walls were more permeable than those

applied to similar backings that were damp

when painted.

(e) Coatings of a paint of thin consistency

(low in powder content) were more permeable

than those of a normal consistency.

(f) The amount of normal-consistency paint

applied was dependent upon the surface texture

of the units used in the walls. Backings of rough

textured cinder-concrete block required more

paint than did those of the relatively smooth

textured stone-concrete block.

(g) Two thick coatings of normal-consistency

paint applied to similar walls with like brushes were less permeable when first applied than two

thinner ones. Wlien again tested after outdoor

weathering, the reverse was true; the average

permeability of thick coatings was found to have

increased, and that of thinner coatings had

decreased.

(h) Within the range tested, the differences

in the relative proportions of portland cement

and of hydrated lime used in the paints had no

consistent effect on the permeability of the

coatings.

(i) The admixture of hygroscopic salts, water

repellents, diatomaceous silica, or of an opaque

pigment did not increase the effectiveness of the paints.

2. Emulsified Resin and Oil-Base Paints

Coatings of an oil-base paint and of the

emulsified resin paints, applied with a paint

brush to walls of concrete blocks, were permeable and much less effective as waterproofings

than the cement-water paints.

3. Colorless Surface Waterproofings

The colorless waterproofings, except a water

emulsion of waxes known as Gargoyle Ceremul-W, were ineffective, and permeable walls

treated with them leaked excessively. Coatings

of Ceremul-W were slightly more permeable

than coatings of cement-water paints. The

Ceremul-W treatments were found to have lost much of their eft'ectiveness when the treated

waUswere again tested after outdoor weathering.

4. Joint Treatments

(a) A highly effective and durable method

of waterproofing brick walls without changing

their appearance was the repointing of the face

joints with mortar.

(b) A portland-cement grout applied to the

joints of brick walls was an effective water-

[36]
proofing. A thin coating of the grout containing

fine sand was brushed over the joints with a

stiff brush, filling minute openings between the

units and the mortar. The permeability of the

treatments was significantly but not seriously

increased by outdoor weathering.

5. Membrane Waterproofing

A series of waterproof membranes built into

the masonry was an effective waterproofing

when drainage of leakage water was provided.

Drainage was obtained through adequate weepholes at the bottom of the facing tier. Wlien

not drained, the leakage water trapped in the

masonry filled the cavities in the wall and ran

over the tops of the membranes.

6. Waterproofings on the Inside (Unexposed) Faces of the Walls

(a) Bituminous coatings applied to tlic inside

faces of brick walls were ineft'ective as waterproofings. Blisters filled with water developed

in the coatings, and the rates of leakage from

blisters that had collapsed was high.

(b) Brush coatings of portland cement and

sand leaked slightly but were more eft'ective as waterproofings than bituminous coatings.

(c) Trowel coatings of portland-cement mortars, prepared with or without the admixture

of iron powder and sal ammoniac, were highly

resistant to water penetration.

Washington, December 5, 1942.

[37]

BUILDING MATERIALS AND STRUCTURES REPORTS

[ContiBued from cover page ii] BMS33 Plastic Calking Materials . 10^ BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 10^ BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 10(S BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions with

"Red Stripe" Lath Sponsored by The Weston Paper and Manufacturing Co 10^ BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors, Sponsored by Palisade Homes lOfi BMS38 Structural Properties of Two "Dunstone" WaU Constructions Sponsored by the W. E. Dunn Manufacturing Co lOjS BMS39 Structural Properties of a WaU Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co 10j5 BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

by Knap America, Inc lOfi BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls 10f5 BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions with "Celotex"

Insulating Boards Sponsored by The Celotex Corporation 15^5 BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 10^ BMS44 Surface Treatment of Steel Prior to Painting 10^ BMS45 Air Infiltration Through Windows 10^ BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 10^ BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions, and Floors Sponsored by American Houses, Inc 10j5 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 10^ BMS49 Metallic Roofing for Low-Cost House Construction lOfi BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 10^ BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the

Tilecrete Co 100 BMS52 Effect of Ceiling Insulation Upon Summer Comfort 10^ BMS53 Structural Properties of a Masonry WaU Construction of "Munlock Dry Wall Brick"

Sponsored by the Munlock Engineering Co lOfi BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 10^ BMS55 Effects of Wetting and Drying on the Permeability of Masonry Walls 10#

BMS56 A Survey of Humidities in Residences 10^ BMS57 Roofing in the United States—Results of a Questionnaire 10^ BMS58 Strength of Soft-Soldered Joints in Copper Tubing 10^ BMS59 Properties of Adhesives for Floor Coverings 10^ BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of BuUding

Bricks Produced in the United States 15^ BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete WaU Constructions 10^ BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 100 BMS63 Moisture Condensation in Building Walls 100 BMS64 Solar Heating of Various Surfaces 100 BMS65 Methods of Estimating Loads in Plumbing Systems 100 BMS66 Plumbing Manual 200 BMS67 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 150 BMS68 Performance Test for Floor Coverings for Use in Low-Cost Housing: Part 3 150 BMS69 StabUity of Fiber Sheathing Boards as Determined by Accelerated Aging 100 BMS70 Asphalt-Prepared RoU Roofings and Shingles 150 BMS71 Fire Tests of Wood- and Metal-Framed Partitions 200 BMS72 Structural Properties of "Precision-Built, Jr." Prefabricated Wood-Frame WaU Construction Sponsored by the Homasote Co 100 BMS73 Indentation Characteristics of Floor Coverings 100 BMS74 Structural and Heat-Transfer Properties of "U. S. S. PanelbUt" Prefabricated SheetSteel Constructions for Walls, Partitions, and Roofs Sponsored by the Tennessee

Coal, Iron & RaUroad Co 150 BMS75 Survey of Roofing Materials in the North Central States 150 BMS76 Effect of Outdoor Exposure on the Water Permeability of Masonry WaUs 150 BMS77 Properties and Performance of Fiber Tile Boards 100 BMS78 Structural, Heat-Transfer, and Water-PermeabiUty Properties of Five Earth-Wall

Constructions 200 BMS79 Water-Distributing Systems for Buildings 150 BMS80 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 4 150 BMS81 Field Inspectors' Check List for BuUding Construction (cloth cover, 5 x 7>^ inches) 200 BMS82 Water Permeability of WaUs Built of Masonry Units 200

[List continued on cover page iv]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page iii] BMS83 Strength of Sleeve Joints in Copper Tubing Made With Various Lead-Base Solders 10^ BMS84 Survey of Roofing Materials in the South Central States 15^ BMS85 Dimensional Changes of Floor Coverings with Changes in Relative Humidity and

Temperature 10^ BMS86 Structural, Heat-Transfer, and Water-PermeabiUty Properties of "Speedbrik" Wall

Construction Sponsored by the General Shale Products Corporation 15^ BMS87 A Method for Developing Specifications for Building Construction-—Report of Subcommittee on Specifications of thej Central Housing ^Committee on Research, Design,

and Construction lOfi BMS88 Recommended Building Code Requirements for New Dwelling Construction with Special Reference to War Housing 20^ BMS89 Structural Properties of "Precision-Built, Jr." (Second Construction) Prefabricated

Wood-Frame Wall Construction Sponsored by the Homasote Co 15^ BMS90 Structural Properties of "PHC" Prefabricated Wood-Frame Constructions for Walls,

Floors, and Roofs Sponsored by the PHC Housing Corporation 15^ BMS91 A Glossary of Housing Terms 15^ BMS92 Fire-Resistance Classifications of BuUding Constructions 25fS BMS93 Accumulation of Moisture in Walls of Frame Construction During Winter Exposure 10^ BMS94 Water Permeability and Weathering Resistance of Stucco-Faced, Gunite-Faced, and

"Knap Concrete Unit" Walls 10«5 BMS95 Tests of Cement-Water Paints and Other Waterproofings for Unit-Masonry Walls 15^