A 51A135.5-2004 

Approved March 11, 2004 

Prefini hed Hardboard Paneling
 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

American 

National 

Standard 

Published by 

Approval of an American Standard requires verification by the 

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requirements for due process, consensus, and other criteria for 

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Board of Standards Review, substantia l agreement has been 

reached by directly and materially affected interests. Substantial 

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toward their resolution. 

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the title page of this standard. 

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Standards Institute require that action be taken period ically to 

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Composite Panel Association 

18922 Premiere Court, Gaithersburg, MD 20879-1574 

Copyright© 2004 by Composite Panel Association 

All rights reserved. 

No part of this publication may be reproduced in any 

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Printed in the United States of America 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

Abstract	 This Standard covers requirements and methods of 

testi ng for the dimensions, sq ua reness, ed ge 

straightness, and moisture content of prefinished 

hardboard paneling and for the finish of the 

paneling. Methods of identifying products which 

conform to the Standard are included. 

This Foreword is not a	 part of American National 

Foreword Standard for Prefinished 

Hardboard Paneling. 

This Standard was originally promulgated under the 

procedures of the U.S. Department of Commerce 

National Bureau of Standards and designated as 

Voluntary Product Standard PS 59-73. This 

American National Standard was updated in 1982 

and 1988. The 1995 revision made editorial 

corrections and adds metric equivalents. This 2004 

revision makes only editorial changes. 

The development of this American National 

Standard for Prefinished Hardboard Paneling offers 

manufacturer, consumer, and the general public 

concerned with the product an effective guide 

developed under the consensus procedures of the 

American National Standards Institute. 

Consensus for this standard was achieved by use of a canvass body and 

ANSI's Essential Requirements for due process. The following organizations, 

recognized as having an interest in hardboard standards, were contacted 

prior to the approval of this standard. Inclusion in this list does not 

necessarily imply that the organization concurred with the submittal of the 

proposed standard to ANSI. 

AFCO Industries Inc. Masonite International Corporation 

AKZO Nobel Coatings, Inc. Institute for Building Technology and 

Georgia-Pacific Corporation Safety 

ICC Evaluation Services, Inc. Stimson Lumber 

Jeld-Wen R&D Stork - Tw in City Testing Corp. 

Kitchen Cabinet Manufacturere Assn. USDA Forest Products Laboratory 

Louisiana-Pacific Corporation University of Illinois 

Manufactured Housing Institute 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

1. SCOPE 

This Standard covers requirements 

and methods of testi ng for the 

dimensions, squareness, edge 

straightness, and moisture content 

of prefinished hardboard paneling 

and for the finish of the panelrnq.' 

2. REQUIREMENTS 

2.1. General. Products 

represented as complying with this 

Standard shall meet all of the 

requirements specified herein. The 

qualification and test procedures 

contained in Section 3 are to be 

used to determine the conformance 

of products to the requirements of 

this Standard. 

Note: Embossed products, because 

of their varying surfaces and 

patterns, requ ire the recognition 

that certain adjustments and 

allowances are to be made in the 

evaluation of various physica l 

property requirements found in this 

Standard. Specific adjustments for 

em bossed products have been 

designated wherever possible. With 

certain proprietary finished surface 

configurations, the manufacturer 

sha II be co nsu Ited fo r specifi c 

adjustments in the test 

procedures. 

Other Standard s cover: a. Basic Hardboard: b. 

Ha rd boa rd Siding. Phy sica l p ropert ie s of th e 

hardboa rd used to manufacture prefinished paneling 

are set out in Am eri can National Stan dard A135.4­

2004 Basic Hardboard Produ cts wh ich conform to the 

req uirements of thi s Standar d are includ ed . 

2.2.	 Dimensions and 

Tolerances. 

The paneling shall have a nominal 

width of 406 mm (16 in.), 1220 

mm (4 ft.) or 1524 mm (5 ft.). 

The nominal length shall be from 

1220 mm (4 ft.) through 3660 mm 

(12 ft.) in 405 mm (1 ft.) 

increments. The nominal thicknesses shall be 3.2 (1/8 in.), 4.8 

(3/16 in.), and 6.4 mm (1/4 in.). 

The tolerance on the nominal 

length and width shall be plus or 

minus 1.6 mm (1/16 inch). The 

thickness range for each nominal 

thickness shall be as specified 

below. 

Nominal Thickness Min.-Max. 

mm inch mm inch 

3 .2 1/8 2.9-3.9 0.115-0.155 

4 .8 3/16 4.2-5.2 0.165-0.205 

6.4 1/4 5.3-6.7 0.210-0.265 

Thickness measurements shall be 

made in accordance with the 

applicable method in Part B of 

ASTM D 1037-99, Test Methods for 

Evaluating the Properties of WoodBas e Fib erand ParticIePane , 

Materials. 

2.3 Squareness. The lengths of 

the diagonals of the paneling shall 

not differ by more than 1.6 rnrn/rn 

(1164 in ./ ft .) of length of the 

paneling. Opposite sides of the 

paneling shall not differ in length 

more than 3.2 mm (118 in.). 

2 

I 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

2.4. Edge Straightness. The 

edges of the paneling shal l be 

straight within 1.6 mrn/rn (1/64 

in ./ ft.) of le ngth or w idth, and 

edges and corners sha ll be square 

cut. Edge straightness shall be 

determined by stretching a string 

or wire from one corner to the 

adjacent corner and measuring the 

widest distance between the string 

or wire and the panel edge being 

tested. 

2.5. Moisture Content. The 

moisture content of the paneling 

shall be not less than 2 percent nor 

more than 9 percent and, within 

anyone shipment, shall not vary 

by more than 3 percentage points 

as measured by the mo isture 

content of the modulus of rupture 

specimens. Moisture content sha ll 

be determined in accordance with 

the applicable test method in Part 

B of ASTM D 1037-99. Since 

hardboard is a wood-base material, its mo isture content will vary with 

environmental humidity conditions. 

When the environmental humidity 

conditions in the area of intended 

use are a critical factor, the 

purchaser shall specify a moisture 

content more restrictive than 2 to 

9 percent so that fluctuation in the 

moisture content of the panel will 

be kept to a minimum. 

2.6. Hardboard Substrate. The 

hardboard substrate of the 

paneling shall be manufactured 

primari ly of int erfe lt ed lignocellulosic fibers which are consolidated under heat and pressure in a 

hot-press to a density of 500kg/m3 

3 

(31 pounds per cub ic foot) or 

greater. The finished product 

when tested shall have the 

properties of one of the classes 

list ed in the American Nationa l 

Standard A135.4-2004 and shall 

have the physica l properties 

specified therein when tested in 

accordance with the applicable test 

methods in Part B of ASTM D1037­

99. 

2.7. Fin ish. The finish of the 

paneling shall be either Class I or 

Class II as specified in Table I, and 

the properties of each class shall 

be determ ined in accordance with 

the sectio ns of th is Sta nda rd 

indicated therein. 

2.8. Workmanship. All surfaces 

shall be un iform in appearance 

throughout, and sha ll be as free 

from visible defects in the surface 

plane as commercially practicable 

when v isually inspected by an 

individual competent in the field. 

2.9. Flame Spread Index. A 

flame spread index for the paneling 

shall be determined by the Tunnel 

Test specified in ASTM E 84-03, 

Test Method for Surface Burning 

Characteristics of B u i / din g 

Materia/s, with the paneling 

mounted with cement backer 

boards . The panels sha ll then be 

class ified as fo llows: 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

Class Flame Spread Index 

I o - 25 

II 26 - 75 

III 76 - 200 

IV over 200 

2.10. Identification. All panel ing 

represented as conforming to this 

Sta nda rd sha II be identified with 

the reference ANSI A135.5. 

3.	 QUALIFICATION AND TEST 

PROCEDURES 

3.1. Abrasion Resistance. 

Abrasion resistance shall be 

determined in accordance with 

ASTM D 968-93(2001), Test 

Method for Abrasion Resistance of 

Organic Coatings by Falling 

Abrasive. 

3.2. Adhesion. Clean the surface 

of the panel with mineral spirits 

and allow it to dry. Make a cut at 

least 25 mm (1 in.) long through 

the finish with a sharp razor blade 

or equivalent. Apply a piece of 20 

mm (3/4 in.) wide flat-back 

masking tape? perpendicular to the 

cut and press firmly in place by 

using a wallpaper seam roller. 

Allow the cut to extend beyond the 

edges of the tape and the tape to 

contact the finish for a distance of 

at least 25 mm (2 in.) on each side 

of the cut. Allow sufficient excess 

2 The masking tape shall be less than one yea r old, 

has been properly store d, and shall have an adhesi ve 

strength of 50 + g/mm (45 + 5 ounces per inch) when 

tested in accordance with ASTM Test Method D3330. 

tape on one side to hold the tape 

between the thumb and forefinger. 

Immediately pull the tape free in a 

slow and even manner at right 

angles to the cut. Measure the 

distance from the cut to the point 

that the finish ceases to be "picked 

up" by the tape. 

Note: This test is applicable only 

to flat surfaces. If a textured 

product is to be tested, a flat area 

of the pattern shall be selected. 

Trial cuts shall be made until either 

the substrate becomes visible in 

the bottom of the cut or, in case of 

inter-coat adhesion, the underlying 

paint film becomes visible in the 

bottom of the cut. Disregard any 

cuts of improper depth, curling at 

the edge or the cut, or excessive 

chipping adjacent to the cut. 

3.3 Fade Resistance. Fad e 

resistance shall be tested using 

Method 1 ASTM G 23-01, Practice 

for Operating Light-and WaterExposure Apparatus (Carbon-Arc 

Type) for Exposure of Nonmetallic 

Materials. Gloss shall be 

determined in accordance with 3.4. 

3.4. Gloss. Gloss shall be 

determined in accordance with 

ASTIVl D 523-99 Test Method for 

Specular Gloss, using a glossmeter 

geometry of 60°. 

3.5. Heat Resistance. Place a 

100 mm by 100 mm (4 in. by 4 

in.) specimen in an oven at 65° C 

(150° F) for 24 hours. 

4 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

3.6. Humidity Resistance. Place 

alSO mm by 300 mm (6 in. by 12 

in.) specimen in at atmosphere of 

90 percent relative humidity and 

temperature of 32°C (90°F) plus or 

rninus 1°C (2 °F) for 240 hours. 

3.7. Scrape Adhesion. Scrape 

adhesion shall be determ ined in 

accordance with Method A of ASTM 

D 2197-02, Test Methods for 

adhesion of Organic Coatings by 

Scrape Adhesion. 

See	 "Note " relative to textured products under 

3.2 Adhesion. 

3.8. Stain Resistance. Sta i n 

resistance shall be tested in 

accordance with ASTM D 1308-02, 

Test Method for Effect of 

Household Chemicals on Clear and 

Pigmented Organic Finishes, using 

the Spot Test, covered method, 

and the following staining agents: 

(a)	 mineral oil (U.S.P.) 

(b) fresh -brewed strong coffee 

(c)	 china-type marking pencil 

(d)	 non-smearing lipstick 

(e) resonstituted lemon juice 

(10% citric acid by weight) 

(f)	 carbonated cola drink 

(g) household ammonia solution 

(10% ammonia by weight) 

(h)	 homogenized milk 

(i)	 alcohol (denatured) 190 

proof 

(j)	 aqueous household bleach 

(5.5% sodium hypochlorite 

by weight) 

(k)	 nail polish remover* 

(I)	 1% trisodiu m phosphate 

solution (by weight) 

* Nail polish remover formula: 

Volume 

Butyl acetate 24% 

Ethyl acetate 28% 

Acetone 20% 

Isopropyl alcohol 24% 

Diglycol laurate 4% 

The staining agent shall be allowed 

to stand on the test specimen for 4 

hours, after which time it shall be 

wiped away using a damp cloth. 

Any stain remaining shall be gently 

removed by rubbing with alcohol or 

lacquer thinner only to the extent 

required to dissolve water insoluble 

surface stains. If 24 hours after 

wiping away the staining agents: 

(1) the specimen is free of marks 

and stains, then the staining agent 

shall be considered as having no 

effect; (2) any residual mark 

and/or stain is easily and 

completely removed by the light 

application of a mild abrasive 

cleaner, then the staining agent 

shall be considered as having only 

a superficial effect. Test 

specimens shall be examined by 

holding the specimen at arm's 

length in a vertica I position under 

overhead white fluorescent lamps 

which produce illumination in the 

range of 810-1080 lux (75- 100 

footca nd les). 

3.9. Steam Resistance. A 500 mL 

narrow-mouth Erlenmeyer flask 

shall be half-filled with water which 

shall be maintained at a mild boil 

at 125 mL/hour evaporation rate. A 

100 mm (4 in.) square sample 

panel shall be suspended 25 mm 

(1 in.) above the mouth of the 

5
 
ANSI A135.5-2004, Prefinished Hardboard Paneling 

flask, with the finished face down, 

for 8 hours (replenish water as 

necessary). The back and edges of 

the specimen shall be protected by 

an acrylic lacquer at least 25~m (1 

mil) dry film thickness which will 

not soften or lose adhesion at 

104°C (220°F). The specimen shall 

then be allowed to recover for 16 

hours before grading. There shall 

be no mo re than a su perficia I 

change in appearance after testing. 

3.10. Washability. The 

washability of the finish with ASTM 

D 2486-00, Test Method for Scrub 

Resistance of Interior Latex Flat 

Wall Paints, inco rpo rati ng the 

following test equipment and 

procedures: Use Gardner 

Washability Machine, Model lOS-a, 

or equivalent, and a Gardner long, 

hog bristle brush" or equivalent. 

Cut a specimen 150 mm by 432 

mm (6 in. by 17 in.). Determine 

the gloss of the coating as 

described in 3.4. and clamp the 

panel firmly in the pan of the 

apparatus. Soak the hog bristle 

brush in a 3.0 percent solution by 

weight of trisodium phosphate for 

10 minutes and place it on the 

panel. Pour 10 milliliters of the 

same solution on the panel, adding 

more solution from time to time to 

keep the specimen moist but not 

3 Available from Pacific ScientificInstruments Div., 2341 Linden Lane, 

Silver Spring, MD 20910. This trade name 

is used solely for the purpose of 

description and does not im pl y 

recommendation or endorsement . Other 

such apparatus equal in performance shall 

be acceptable. 

soaking wet. Remove the specimen 

after 3,000 cycles (6,000 separate 

strokes), rinse with running water, 

wipe off with clean sponge, and 

allow the specimen to dry at a 

temperature of 22°C plus or minus 

3°C (72°F plus or minus 5°F) for 2 

hours. Redetermine the gloss 

within the central 200 mm (8 in.) 

of the brush path in accordance 

with 3.4, and report the increase or 

decrease in gloss units. 

6
 
ANSI A135 .5-2004, Prefinished Hardboard Paneling 

Table 1 

Properties of Hardboard Paneling Finishes 

Requirements 

Property Class I Class II Reference to paragraph 

in this Standard 

Ab rasion resistance 5 liters of sand without marring 

print or undercoat 

3 lite rs of sand without ma rring 

print or undercoat 

3.1 

Adhesion Less than 3 .2 mm (1/8 in .) of 

coat ing "picked up" 

Same as Class I 3.2 

Fade resistance 100 hours of light exposure with no 

loss of g loss and only a slight colo r 

change when vi sua lly inspected by 

an individual competent in the field 

60 hours of ligh t ex posure with no 

loss of gloss and only a slight color 

chang e w hen visually in spected by 

an individual competent in the field 

3.3 

Gloss - High 

Medium 

Low 

50 units and ove r 

25 to 50 units 

Under 25 un it s 

Same as Class I 3 .4 

Heat resistance Slight co lor change wh en vis ua lly 

inspected by an individual com petent 

th e field 

See footnote 4 3.5 

Humidity resistance No blistering , peeling, cracking, 

cra zing, or mo re than a sl ight color 

change when vi sually inspected by 

an individual competent in the fie ld 

See footnote 4 3.6 

Scrape ad hesion 6 kilog rams 4 ki lograms 3.7 

Stain resistance No eff ect us ing staining agents (a) 

through (i) 

No effe ct using sta in ing agents (a ) 

through (f) . Not greater t han superficial effect using staining age nts 

( g) t hrough (I) . 

3 .8 

Steam res istance No blistering, loos ening, or se paration of coa ting 

See foo t note 4 3 .9 

Washability No loss of print or undercoat Same as Class 1 3.10 

4 Class II fi nish has lim ited heat, humidity, or steam resistance requ irem ents as it is not meant to be 

used where these con diti ons are excessive such as aro und stoves, fu rn aces, showers and bath t ubs. 

Note: Physical properties of the hardboard substrate can be found in the 

American l\Jational Standard ANSI A135.4-2004, Basic Hardboard. 

7 
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