TECIiiniCAL Iia‘'0i2.L:.Tl01I ON BUILDING ViaTI^HIaLB

FOR UDB IN THE DESIGIJ OF LON-COBT HOUSING

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TTiE IiiaTIONxjIj BUrdiiiU 01 STLinLiRDIi

UTILTED STlTEB DEPAi-JTi.JBi'fl oF COliffiRGE

UlBHINGTON, D. G.

April 0, 1936

ENTEliIQR NjiTLliPROOFIiJG rOR liLBOlTRY

This is a digest of Research Paper iiP77i (Ivlarch 1935},^ ’'Experiments on Exterior \/aterproofing Lfeterials for liasonry”, by Daniel \u Kessler,

issued by the National Bureau of Standards.

Pur]:ose ; To determine the effectiveness and durability of waterproofing treatments on masonry.

Materials used : Twenty-nine representative proprietary and ten

non-proprietary treatments were applied in accordance with manufacturers’

recommendations on lEiestone, sandstone, iroarbie, bricic, cast stone and

Liortar (1:3 cement and sand) and tested at intervals of I to 3 months

over exposure periods up to 12 years.

The materials v/ere grouped as foilov/s:

Proprietary Non-Proprietary

(1) Thinned fatty oils

(2) Thinned fatty oils and paraffin

(3) Thinned varnishes

(4:) ii-iuminuia soap solutions

(5) iiqueous emulsions

(6) Bax solutions in volatile solvents

(7) Fluosilicate types

(8) Pyroxylin t;/pes

(9) Aqueous solutions

(10) hiolten paraffin

(11) ' \;ax solutions in vo la tine solvents

will be shown, compositions var:/ in effectiveness and durability;

treatments are not equally effective on different pore structures; nor are

they productive of waterproofing to the same degree with any given t^-pe

of masonry.

\)btainable from Superintendent of Docuiaents, Government Printing

Office, Washington, D. C. (Price 5 cents)

040736-2,

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In general, the ruore porous liiaterials are raore easily waterproofed

and fine-pore structures are most difficult', ijaterproof ings should be

adapted to pore structure rather than to types of iiiasonry; adequate surface penetration is a very essential requisite.

Suitable treatment for any particular masonry is best determined

by preliminary experiment with samples of material to be waterproofed.

To determine effectiveness, penetration, and discoloration, rough dry

fragments of masonry t\\fo or three inches in diameter should be v/eighed

when dry, and after thirty minutes immersion in water, and the difference

noted, hfter thoroughly drying the sample, applying treatment and again

drying for two days, the difference in \/eight should again be tahen between

that in the dry condition, and after thirty minutes imiaersion. Une coat

of waterproofing should z'educe the absorption v/eight by at least ninety

percent

.

Approximate penetration of wateipjrnof ing will be indicated by breaking the treated saiuple and dipping it in vmter. For coimiion types of

brick, limestone, and sandstone, penetration should be from one eighth

to one fourth inch; for denser materials, one sixteenth inch should prove

satisfactory.

For medium to coarse textures a very durable and economical treatment may be made by. dissolving six to twelve ounces of high-melting-point

paraffin to a gallon of solvent such as naphtha, gasoline, etc. For

fine-pore structures, add three to six ounces of china oil to the gallon.

All treatments should be applied only to dry masonry and in warm weather.

Discoloration can be best judged by comparing treated with untreated

saraples. .

He suits : Dirmaary observations applying more particularly to results

obtained as a group appear below:

(1) Thin fatty oil treatments were fairly satisfactory with medium

textures but not adapted to fine or coarse types of masonry. Treatiaents

of this group containing appreciable amoimrs of aluminura soap deteriorated

rapidly when applied to limestone, suggesting possible saponification,

ilediuin textured sandstones satisfactorily watex’proofed showed a low rate

of deterioration. Oily discoloration was produced.

(2) Fatty oils and paraffin in volatile solvents ga've high waterproofing and durability values in most cases. Hif^her oil content was less

effective on fine-pore structures; however, with such treatments consistency should be adapted to pore structure. Discoloration occurred to

approximately the same degree as with thin fatty oils.

(5) Thin varnishes were not generally effective and showed a tendency to prevent the escape of absorbed water. Discoloration was ex- cessive and more pronouirced than witii fatty oils.

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(4) Aluninuia soap solutions gave high initial waterproofing results,

shovving also a high rate of deterioration, effectiveness failing on an

average at tv:o years. Additions of small ar;iounts of wax or oil increased

duratility slicihtly. Discoloration was slight.

(5) j^cuecus emulsions of waxes and oils v;ere generally unsatisfactory.

Penetration was poor; the surface film discoloring and collecting dust.

(o) L (11) Paraffin in volatile solvents was effective and durable.

Lffectiveness on fine-pore structures was improved by addition of small

quantities of fatty oils. Paraffin should have melting point above summer

wp.ll temperatures (130° r is satisfactory) to prevent flow from pores.

Discoloration of an oily appearance is produced by this treatment.

(7) The fluosilicate treatments (magnesium fluosilicate or magnesiuia

zinc fluosilicate) showed no waterp’roofing value,

(b) P^'-roxylin tjrpes (cellulose nitrate, ethyl acetate, etc.) showed

little penetration. The suu'face filiu 'weathered away in a short time,

producing a glossy splotchy appearance.

(9) Two separate aqueous solutions (ai.um and potassiura soap or sodium silicate and calcium chloride) applied separately'-, reacting with

each other to produce insoluble precipitates gave generally poor results

and showed tendency toward disintegration of masonry.

(10) liolten paraffin applied to surface, heated above that of

melting point uf \/ax (135° 1 or higher) , gave very satisfactory results

and excellent durability, nny surplus film of surface wax should be

removed to prevent excessive discoloration and dirt accumulation.

General observations ; Preservative value of treatments on si:iall

specimens of Ijcuestone and marble was observed and although not conclusive,

showed that effecti’/e v/aterproofing appeared to retard corimon types of

weathering deterioration. Other materials, including masonry, were not

tested

.

Destructive effects accompanying efflorescence and by the solvent

action of rain water on limestone and marble were materially reduced by

effective waterproofing treatments. There also ?/ere appreciable differences in surface appearances, those with durable treatments being smoother

and usually- cleaner.

Discoloration disappeared in most cases after a few months exposure

with treated parts of lighter shade than those untreated. Specimens with

durable treatments remained cleaner for several years.

Prest resistance appeared to be increased by effective wu.terproof ing

treatments although the exporh/ients were too meagre to warrant final

conclusions in this respect.

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