ASTM C473 - 03

Designation: C 473 ± 03

Standard Test Methods for

Physical Testing of Gypsum Panel Products

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This standard is issued under the ®xed designation C 473; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 3 Annual Book of ASTM Standards, Vol 15.09. 

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Scope* 

1.1 These test methods cover the physical testing of gypsum panel products.  1.2 The test methods appear in the following order:  Flexural Strength (Method A) Core, End and Edge Hardness (Method A) Nail Pull Resistance (Method A) Flexural Strength (Method B) Core, End and Edge Hardness (Method B) Nail Pull Resistance (Method B) Humidi®ed De¯ection End Squareness Nominal Thickness Recessed- or Tapered Edge Depth Width Length Water Resistance of Core-Treated Water-Repellent Gypsum Panel Products Surface Water Resistance of Gypsum Panel Products with Water-Repellent Surfaces

1.3 The text of these test methods references notes and footnotes that provide explanatory material. These  notes  and footnotes,  excluding those in tables  and   ®gures,  shall  not  be   considered   as requirements of these test methods.  1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard   to   establish   appro­priate   safety   and health   practices   and   determine   the   applica­ bility of regulatory limitations prior to use.  2.

Referenced Documents  2.1 ASTM Standards:  C 11 Terminology Relating to Gypsum and  Related Build­ing Materials and Systems2 D 3285 Test Method for Water  Absorptiveness of Nonbibu­lous Paper and  Paperboard (Cobb Test)3

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These   test   methods   are   under   the   jurisdiction   of   ASTM Committee C11 on Gypsum and Related Building Materials and Systems   and   are   the   direct   responsi­bility   of   Subcommittee C11.01   on   Speci®cations   and   Test   Methods   for   Gypsum Products.  Current edition approved June 10, 2003. Published August 2003.   Originally   approved   in   1961.   Last   previous   edition approved in 2000 as C 473 ± 00.  2 Annual Book of ASTM Standards, Vol 04.01. 

relative humidity of 50 6 

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E 4  Practices for Force Veri®cation of  Testing Machines4 3.

Terminology 

3.1 De®nitions   used   in   these   test   methods   are   in accordance with Terminology C 11.  3.2 De®nitions   of   Terms   Speci®c   to   This Standard:  3.2.1 edge, nÐthe paper­bound edge, or long edge, as manufactured.  3.2.2 ends,  nÐthe   end   perpendicular   to   the paper­bound edge or long edge.  4.

Sampling 

4.1 For   use   in   these   test   methods,   a   sample   shall consist of not less than 0.25 % of the number of gypsum panel  products in a shipment, but not less   than   three   gypsum   panel   products.   Test specimens shall be taken from the sample lot as indicated in each method.  5.

%  (Note  1).  Test  specimens  individually  after constant  weight  is reached and within 10 min upon removal from the conditioning chamber.  NOTE  1ÐLaboratory   test   results   indicated   that conditioning tempera­tures may range from 70 to 100°F (21 to 38°C) without signi®cantly affecting the results. However, relative humidity is critical. This is the reason for testing specimens within 10 min upon removal from the conditioning chamber.

Method AÐConstant Rate of  Loading INTRODUCTION The   following   procedures   are   applicable   to so­called   ªshot   machinesº   that   utilize   lead   or steel shot that applies a load to the specimen at a constant   stress   rate   or   any   other   device   that applies the load at a constant stress rate.

Conditioning 

5.1 Condition   specimens   to   constant   weight   at   a temperature   of   85  6  15°F   (29.5  6  8.5°C)   and

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 Annual Book of ASTM Standards, Vol 03.01.

*A Summary of Changes section appears at the end of this standard. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

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C 473 ± 03 Method ÐFlexu ral properti es   of gyp­ sum panel 6.1 Testing product Machin s   are eÐAppl evaluat y   the ed   by test support load   at ing   the a specim uniform en   near rate  of the 1   lbf/s ends (4.45 and N/s) applyin 610   %. g   a Apply transver the load se   load with   a midway device betwee indepen n   the dent   of support manual s.  control of   the 7.2 Signi® cance rate   of and loading UseÐT during his   test an method individ covers ual a   pro­ sample cedure test (see Fig.   1). for The evaluati deform ng   the ation of ability the of specim gypsum en panel controls product the s   to cross withsta head nd speed.  ˉexural stresses 7. Flex during ural handlin Stre g or use ngth of   the (Met materia l.   This hod test A)  method 7.1 Summa is   used ry   of to Test 6.

App arat usÐ Met hod A 

determi ne complia nce with gypsum panel product speci® cations. The degree of correlat ion betwee n   this test and service perform ance has   not been fully determi ned.  7.3 A p p a r a t u s Ð S e e S e c t i o n 6 . 1 .  7.3.1 Specim en Suppor tsÐAll specim en bearing support s   and load surface s   shall

be   true, shall engage the   full width of   the test specim en, shall be of   such strength they will not deform under the   test load, and shall be rounde d   to   a radius of 0.125 in.   (3.2 mm). The specim en support s   shall be spaced 14  6 0.016 in. (356 6 0.41 mm) on centers measur ed   at the points of surface contact with the specim en.   The support s   shall be attache d   to   a plate that shall be rigidly attache d to the test apparat

us.   The support s   shall be parallel to   each other and perpend icular to   the long dimensi on   of the   test specim en.   The bearing surface of   the end support s   shall be   on the same plane to ensure contact along the entire bearing surface s. Support s   shall be   not less than   12 in. (305 mm)   in length. When a load   is being applied, the loading bar shall be in contact with the full width of   the specim en.   The load­ bearing surface shall be

parallel to   the bearing surface of   the specim en support s.   The specim en   and support s   shall be located so   that the vertical axis through the center of   the load­ bearing surface passes through the specim en   at one half of   the specim en width and one half   of the distanc e betwee n   the support s. 7.4 S a m p l i n g Ð S a m p li n g s h

in. a dimensi l l on b parallel e to   the i edge n a c c o r d a n c e FIG. 1 Apparatus Schematic for w Core, i End, t and h Edge S Hardn e ess c Test ­ tion 4.  7.5 T e s t S p e c i m e n s :  7.5.1 Cut four specime ns,   each 12   in. (305 mm)   by approxi­ mately 16   in. (406 mm) from each gypsum panel product in   the sample, two having the   16­

and two7.6.1 having Use   the apparat the   16­ us   in in. 7.3, dimensi support on ing perpend each icular specim to   the en edge. centrall Cut   the y   on specime the ns   not ®xed less parallel than   4 bearing in. (102 s,   14­ mm) in. (356 away mm) on from centers, the and ends apply and the load edges on   a of   the similar gypsum bearing panel midwa product y except betwee where n   the the support product s. is 24­in. Positio or   less n in perforat width, ed where it gypsum is lath   so impossi the load ble   to is   not do so. applied 7.5. over 2  perforat Co ions.  ndit ion  7.6.2 For spe specim cim ens ens  with in  the acc long ord dimensi anc on e  parallel wit to   the h  edge, Sec test one tion specim 5.  en from each 7.6  gypsum Pr panel oce product dur face   up e:

and   the other face down. For specim ens with the long dimensi on perpen dicular to   the edge, test one specim en from each gypsum panel product face   up and   the other face down.  7.6.3 For   gypsum panel product s   with surfacin g material ,   the load   is determi ned   at the time of transver se failure of   the surfacin g material and core through the thickne ss   of the specime n.   The specime ns   shall not show   a break in 7.7

the bond betwee n   the surfacin g   and the core before transver se failure of   the gypsum panel product .   If   a single specime n   fails, test two addition al specime ns   from the same sample, and,   if either one   of the   two specime n   fail, the sample has failed. For gypsum panel product s without surfacin g material ,   the load   is deter­ mined at   the time   of transver se failure through the thickne ss   of the specime n.  Report

ÐCalcu late and report the average 8.1 breakin g   load in pound­ force or newton s   for each test conditi on, rounde d to the nearest 1   lbf (N). The test conditi ons are: (1) parallel ,   face up;   (2) parallel ,   face down; (3) perpen 8.2 dicular, face up; and, (4) perpen dicular, face down.  7.8 Precisi on   and BiasÐT he precisio n   and bias for this test method has   not been determi ned.  8.

Cor e, End, and Edg e Har dnes s

(Met hod A)  Summa ry   of Test Method ÐThe core, end, and edge hardnes s   of gypsum panel product s   is evaluate d   by determi ning the force required to   push a   steel punch into   the area   of test. 

Signi® cance and UseÐT his   test method covers a   pro­ cedure for evaluati ng   the ability of   the gypsum panel product core, ends, and edges to resist crushin g during handlin g or use of   the materia l.   This test method

is   used to determi ne compli­ ance with gypsum panel product speci® cations. The degree of correlat ion betwee n   these test method s   and service perfor­ mance has   not been determi ned.  8.3 Appara tusÐSee 6.1. Clamp or secure the specime n to  the base   of the   test apparat us shown in Fig. 1 with the face   of the specime n perpend icular to the base of   the test apparat us   and parallel to   the movem ent   of the steel punch. Secure

the steel punch to   the moving head   of the   test apparat us, position ed   so that   its center axis   is parallel eith   the line   of travel and   so that   the punch is inserted into   the core equidist ant from the surfaces of   the specime n. Use a steel punch 0.099  6 0.003 in. (2.515 6  0.076 mm)   in diamete r   and more than  1¤2 in. (12.7 mm) long with the bearing surface machin ed   to   a 90° angle in referenc e   to   the punch center line (see Fig.   1 for   test setup schemat ic). 

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C 473 ± 03 8.4 S a m p l i n g Ð S a m p li n g s h a ll b e i n a c c o r d a n c e w it h S e c ­ tion 4.  8.5 T e s t S p e c i m e n s :  8.5.1 Specimens for

Core Hardne ssÐUsi ng   a table   or band saw, cut   one specim en from the center of   each of   the three gypsum panel product samples approxi mately 12   by not   less than   3 in. (305 by   76 mm), with the 12­in. dimensi on perpend icular to   the edges of   the product s,   for   a total   of not   less than three specim ens. The smaller, not   less than   3 in., dimen­ sion will vary dependi ng   on the speci®c punch

length 8.5.1 from and one opening mill­cut in   the end   of testing the machin gypsum es. panel Place product the ,   with sample the   12­ in   the in. tester, (305­ with the mm) loading dimensi arm   in on a perpend horizon icular tal to   the position edges, and for   a with the total   of punch not   less resting than on   the three specim specim en. Saw ens, cuts and   run along tests the   12­ only   on in. the dimensi mill­cut on shall end   of be the smooth specim and ens.  square 8.5.3 with the Specimens smaller for (not Edge less Hardne than   3­ ssÐCut specim in.) ens   the dimensi same on,   as size and well   as method with the as specim describ en.  ed   in 8.5.2 8.5.1 Specimens from for End the Hardne opposit ssÐCut e   edges specim of   each ens   the gypsum panel same product size and ,   with method the   12 as in. (305 describ mm) ed   in dimensi

on   of the specim ens parallel with the edges, for   a total   of not   less than six specim ens. For gypsum panel product s   with surfacin g materia l,   cut   a 1 ¤4  to 1 ¤2­in. (6   to 13­mm) strip   of surfacin g materia l   from the edge   of the   test specim ens expos­ ing   the core for test. Remov e   as little   of the core as possibl e   when removi ng   the surfacin g materia l. Prepare the ®rst test area 2 6 1 ¤2  in. (51  6 13 mm) from one edge   of the specim en, with

the next two test areas approxi mately 4   in. (102 mm) apart.  8.5.4 Conditi on spe cim ens in acc ord anc e wit h Sec tion 5.  8.6 Proced ureÐUs ing   the apparat us   in 8.3, clamp or secure the specim en   in   a ®xed vertical position on   its 12   in. (305 mm) dimensi on edge (see Fig.   1 for   test setup schema tic.   If necessa ry, modify the ˉexural strength test equipm ent   to conduct the

core, push end, the and steel edge punch a hardnes distanc s   test). e of  1¤2 Place in.   (13 this test mm) surface into   the not   less core   of than   1 the in.   (25 specim mm) en. above 8.6.1 the grip Procedure of   the for specim Core en Hardne holder. ssÐTest Conduc either t   three of   the tests 12­in. spaced (305­ approxi mm) mately saw   cut 4   in. edges, (102 for   a mm) total   of apart on not   less each than specim nine en, with tests the ®rst (three test per area 2 6 1 specim ¤2 in. en).  (51 6 8.6.2 13 mm) from Proced one ure edge   of for the En specim d en. Ha Positio rdn n   the ess steel ÐT punch est over the the test 12­ area in. and (30 apply 5­  the am) mill­cut load. end, for Report a   total as   the of   not core, less end,   or than edge nine hardnes tests s   the (three load per require specim d   to en). 

8.6.3 8.7 Procedure for Edge Hardne ssÐTest areas along the  12­ in. (305­ mm) edge, for   a total   of not   less than eightee n tests ( three per specim en). For product s   with surfacin g materia l,   test where the surfacin g materia l   has been remove d. 

Report ÐRepor t   the core, end, and edge hardnes s   indi­ vidually as   the average load   in pounds­ force or newton s rounded to   the nearest 1   lbf (N). Discard any single test value that varies from the average by more than   15 %   and repeat the   test on   the same sample to obtain a new value.  8.8 Precisi on   and BiasÐT he precisio n   and bias   of this   test method has   not been determi ned.  9.

Nail Pull Resi stan

ce (Met hod A)  9.1 Summa ry   of Test Method ÐThe ability of gypsum panel product s   to resist nail pull­ through is evaluat ed   by determi ning the load require d   to push   a standar d   nail head through the product .  9.2 Signi®c ance 9.3 and UseÐTh is   test method covers a pro­ cedure for evaluati ng   the ability of gypsum panel products to   resist nail pull­ through by determi ning   the load required to   force

a standard nail head through the product. This test method is   used to determi ne complia nce with gypsum panel product speci®c ations. The degree of correlati on between these test methods and service perform ance has not been determi ned. 

Appara tusÐSe e   6.1. This apparat us   shall be   used with either of   the specime n support plates in   9.3.1 or 9.3.2.  9.3.1 Fig.   2 shows   a schemat ic   of   a nail pull resistan ce apparatu s

adaptabl e   to   a typical ˉexural strength apparatu s commo nly used in   the gypsum industry .   The specime n support plate shall have   a 3­in. (76­ mm) diamete r hole in the center. The support plate shall   be not   less than   6 by   6   in. (152   by 152 mm).   It shall   be attached to   the apparatu s   as necessar y   to maintai n   the surface of   the plate perpend icular to the travel of the   test nail. The support plate must also   be located so   that the

vertical axis through the center of   the nail shank passes through the center of   the hole   in the support plate. The   test nail shank shall   be 0.099  6 0.003 in. (2.515 6 0.076 mm)   in diamete r   and the   nail head shall   be 0.2506 0.005 in. (6.350 6 0.127 mm)   in diamete r.   The nail shall   be attached at   the head   to the movable cross head   of the   test apparatu s.   This attachm ent shall not exceed the diamete r   of   the nail head and

shall   be placed directly over   the head.   It shall also   be attached so   that the vertical axis through the   nail shank   is parallel with   the travel. 

9.3.2 Fig.   3 shows a schemat ic of an alternat e   nail pull resistan ce apparat us adaptab le   to   a typical ˉexural strength apparat us commo nly used   in the gypsum industry .   This appa­ ratus mirrors all   of the require ments of 9.3.1, except that   the

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nail   is not attache d at  the head   to the movabl e   cross head   of the   test apparat us.   The alternat e apparat us utilizes a machin ed plunger with the nail head and shank incorpo rated   as an 

FIG. 2 App arat us Sch em atic for Nail Pull Res ista nce Test

C 473 ± 03

FIG. 3 Nail Pull Specimen Support Plate

integral part of  the plunger. The plunger ®ts into a bushing that  keeps the nail  aligned 

perpendicular to the test  specimen. 9.4  SamplingÐSam pling shall be in  accordance with Sec­tion 4.

9.5  Test  Specimens: 9.5.1 Cut ®ve specimens   6   by 6   in.   (152   by 152 mm) from a strip   cut   across 4

the   width   of each   48­in. (1220­mm) gypsum   panel product   starting not   less   than   4 in. (102 mm) in from the

C 473 ± 03 edge. Cut   a total   of ®ve specime ns   from more than one   full width 9.6 strip from gypsum panel product s   less than   38 in. (965 mm) wide. Do   not cut   the specime n closer than   3 in.   (76 mm) from the product edges. 9.5.2 Drill   a  7¤64­ in. (2.778­ mm) diamete r   pilot hole through the thickne ss   of the gypsum panel product in   the center of   each test specime n   and perpend icular to   the surface. 9.5.3 Conditi on spe cim ens

in acc ord anc e wit h Sec tion 5.  Proced ureÐUsi ng   the apparatu s in 9.3, center the specime n   face up   on the   base plate and manuall y   lower the   test nail, insertin g   the nail shank in the pilot hole, until the nail head   is ˉush with   the surface of   the specime n. Apply the   load until the maximu m   load is achieve d. Normall y,   this will occur as the   nail head breaks through the

gypsum panel product surface. 

9.7 Report ÐCalcu late   the average maximu m   load in pounds­ force or newton s, rounded to   the nearest 1   lbf (N). Discard any single test that varies from the average by more than   15 %.   If more than   15 %   of the   test values are discard ed, repeat the test. 9.8 Precisi on   and BiasÐT he precisio n   and bias   of this  test method has   not been determi ned.  M et ho d  B Ð C

on st an t  R at e  of  Cr os s  H ea d  Sp ee d

correlat ion betwee n   this test   and service perform ance has   not been fully determi ned. 11.3   Appa ratus ÐSee Secti on  10. 11.3. 1 Specim en Support sÐAll bearing support s   and load surfaces shall   be true, shall engage the   full width of   the test specime n,   shall be   of such strength they will   not deform under the   test load, and shall   be rounded to   a radius of 0.125 in.   (3.2 mm). The specime n

support s   shall be spaced 14  6 0.016 in. (356 6  0.41 mm) on centers measur ed   at the points of surface contact with the specime n.   The support s   shall be attache d   to   a plate that shall   be rigidly attache d to the test apparat us. Test specime n support s   shall be parallel to   each other and perpen­ dicular to   the long dimensi on   of the   test specime n.   The bearing surface of   the end support s   shall be   on the same plane to ensure

contact n along support the s.   The entire specime bearing n   and surfaces specime . n Support support s   shall s   shall be   not be less located than   12 so   that in. (305 the mm)   in vertical length. axis When   a through load   is the being center applied, of   the the load­ loading bearing bar surface shall   be passes in through contact the with the specime full n at one width half   of of   the the specime specime n.   The n   width load­ and one bearing half   of surface the shall   be distance parallel betwee to   the n   the bearing support surface s   (see of   the Fig. 4). specime and data INTRODUC acquisiti TION The followin g procedu res   are applicab le to so­ called univer­ sal   test machine s. These instrum ents often use electron ic   load cells

on equipm ent   to gather informa tion about the specime n   being tested. The instrum ents generall y in use move the cross

m   of the   test equipm ent shall be of sufficie nt   size to accept the specim en holder and load applyin g apparat us.   The testing machin e   shall be power operate d   and shall apply 10. Ap the load par continu atu ously and s  without 10.1Testing shock.  Machin 10.2The test e,   of apparat any us   shall type be that   is veri®e of d sufficie accordi nt ng   to capacit Practice y   and s   E   4, that   is the capable three of sections providi titled ng   a ªBasis rate   of of loading Veri®c at   a ation,º strain ªCorrec rate   of tions,º 1.0 and in./min ªTime 6  5   s Interval (25 Betwee mm/mi n n  6  5 Veri®c s).   The ations.º  load 10.3Load­ platfor Indicati head   at a constant speed, as opposed to having the deforma tion   on the specime n control cross head speed, which would be   a true constant rate   of strain instrum ent.

transver ng Equipm se   load ent, midway capable betwee of n   the reading support to  1­lbf s.  (4.45­ 11.2Signi® N) cance increme and nts, UseÐT shall be his   test provide method d   for covers the   test a apparat procedu us.   A re   for means evaluati shall be ng   the provide ability d   to of indicate gypsum the panel maxim product um load s   to attained withsta during nd the test. ˉexural stresses 11. Fle during xur handlin al g or use of   the Str materia eng l.   This th test (M method eth is   used od to B)  determi

11.1Summa ry   of Test Method ÐFlexu ral properti es   of gyp­ sum panel product s   are evaluat ed   by support ing   the specim en   near the ends and applyin g   a

ne complia nce with gypsum panel product speci® cations. The degree of 

m 11.4S e a n m : p   l i11.5.1 nCut   four g specime Ð ns, each S 12   in. a (305 m mm) by p approxi l mately i 16   in. n (406 g mm) from   each s h gypsum a panel product l in   the l sample,   b two e having the   16­   in. i n dimensi on   a parallel c to   the c edge o and two having r d the   16­ a in. n dimensi c on e perpend icular   w to   the edge. i Cut   the t h specime ns   not   S less e than   4 c in. (102 mm) ­ away   from tion 4.  the 11.5T ends e and s edges t of   the   gypsum S panel p product e except c where i the

product is   not applied is 24­in. over or   less perforat in ions.  width, where it11.6.2 is For impossi specime ble   to ns   with do so.  the long dimensi 11.5.2 on Conditio parallel n to   the speci edge, men test   one s   in specime n   from acco each rdan gypsum ce panel with product Secti face   up on 5. and   the other 11.6 face Proc down. edur For e:  specime 11.6.1 ns   with Use   the the long apparat dimensi us   in on 11.3, perpend supporti icular ng   each to   the specime edge, n test   one centrall specime y on the n   from ®xed each parallel gypsum support panel s, 14­in. product (356­ face   up mm) on and   the centers, other and face apply down.  the load11.6.3 on   aFor   gypsum similar panel bearing product midway s   with betwee surfacin n   the g support material s. ,   the Position load   is perforat determi ed ned   at gypsum the time lath   so of the load

transver se failure of   the surfacin g material and core through the thickne ss   of the specime n.   The specime ns   shall not show   a break in the bond betwee n   the surfacin g   and the core before transver se failure of   the gypsum panel product .   If   a single specime n   fails, test two addition 5

al specime ns   from the same sample, and,   if either one   of the   two specime ns   fail, the sample has failed. For gypsum panel product s without surfacin g material ,   the load   is deter­ mined at   the time   of transver se failure through the thickne ss   of the specime n. 

C 473 ± 03

FIG. 4 Testing Machine

r e c i s i o n   a n d   B i a s :

11.7ReportÐ Calculat e   and report the average breakin g  load in pounds­ force   or newtons for  each test conditio n, rounded to   the 11.8.1 nearest PrecisionÐT 1   lbf he 95 % (N). The repeatab test ility conditio limit   of ns   are: the   Par­ (1) allel, parallel, Face Up face   up; (Method (2) B)   test parallel, is   the face test down; result (3) 64.796 perpend lbf icular, [21.33 face   up; N].   The and,   (4) 95   % perpend reprodu icular, cibility face limit   of down.  the Parallel, 11.8P

Face Up 95   % (Method reprodu B)   test cibility is   the limit   of test the result Across, Face Up 68.992 (Method lbf B)   test [40.00 is   the N].  test 11.8.2 result PrecisionÐT 613.368 he 95 % lbf repeatab [59.46 ility N].  limit   of the   Par­ 11.8.4 allel, PrecisionÐT Face he 95 % Down repeatab (Method ility B)   test limit   of is   the the test Across, result Face Down 65.087 (Method lbf B)   test [22.63 is   the N].   The test 95   % result reprodu cibility 611.704 limit   of lbf the [52.06 Parallel, N].   The Face 95   % Down reprodu (Method cibility B)   test limit   of is   the the test Across, result Face Down 67.370 (Method lbf B)   test [32.78 is   the N].  test 11.8.3 result PrecisionÐT 619.429 he 95 % lbf repeatab [86.42 ility N].  limit   of the 11.8.5 Across, BiasÐNo Face Up informat (Method ion   can B)   test be is   the presente test d on the result bias  of 610.290 the lbf procedu [45.77 re   in N].   The these

test methods for measuri ng   the Flexural Strength (Method B) because there   is no material having an accepte d referenc e value.  12. Cor e, En d, and Edg e Har dne ss (Me tho d B)  12.1 Summar y of Test Method ÐThe core, end,   and edge hardness of gypsum panel products is evaluate d   by determin ing   the force required to push a steel punch into   the area   of test. 

12.2Signi®c ance

and UseÐTh is   test method covers a procedu re   for evaluati ng   the ability of   the gypsum panel product core, ends, and edges to resist crushing during han­ dling   or use   of the material .   This test method is   used to determi ne complia nce with gypsum panel product speci®c a­tions. The degree of correlati on between this   test method and service perform ance has not been fully determi ned. 

12.3   Appa ratus ÐSee  Sectio n 10. 12.3.1 A   means   of securing the specime n   to   the base   of the   test apparatu s   shall be provide d.   The face   of the specime n   shall be perpend icular to the   base of   the test apparatu s   and parallel to   the moveme nt of the steel punch. The steel punch shall   be secured to   the moving head   of the   test apparatu s.   It shall   be position ed   so that   its center axis   is parallel with   the line   of travel. It also shall   be

position ed   so that   the punch is inserted into   the core equidist ant from the surfaces of   the specime n.   The steel punch shall   be 0.099  6 0.003 in. (2.515  6 0.076 mm)   in diameter and more than  1¤2 in. (12.7 mm) long with   the bearing surface machine d   to   a 90° angle   in referenc e   to   the punch center line (see Fig.   5 and   Fig. 6).  12.4S a m p l i n g Ð S a m p l i n

g   s h a l l b e   i n   a c c o r d a n c e   w i t h   S e c ­  

n   not less than   12 by 3 in. (305   by 76   mm) from the center of   each gypsum panel product, for   a total   of not   less than three specime ns.   The 12­in. (305­ mm) dimensi on   shall be perpend icular to the edges of the gypsum panel product. tion 4.  Cuts 12.5T along e the   12 s in.   (305 t mm)   dimensi S on   shall p be e smooth c and i m perpend icular to e the   face n of   the s specime : n.  12.5.1 12.5.2 Specimens Specimens for for   End Core Hardne Hardne ssÐCut ssÐUsi ng   a a specime table   or band n   not less saw, cut a than   12 by 3 in. specime

(305   by 76   mm) from one mill­cut end   of each gypsum panel product, for   a total   of not   less than three specime ns.   Cut the   12­ in. (305­ mm) dimensi on perpend icular to the edges of the gypsum panel product. 12.5.3 Specimens for Edge Hardne ssÐCut a specime n   not less than 12   by   3 in.   (305 by   76 mm) from each edge   of each gypsum panel product, for   a total   of not   less than   six 6

speci­ mens. Cut   the 12­in. (305­ mm) dimensi on parallel to   the edge   of the gypsum panel product. For gypsum panel products with surfacin g material ,   cut   a 1 ¤4  to 1 ¤2­in. (6 to 13­ mm) strip   of surfacin g material from the edge   of the   test specime ns expos­ ing   the core   for test. Remove as   little of   the core   as possible when removin g   the surfacin g material . Prepare the   ®rst test 

C 473 ± 03

FIG. 5 Test SetupÐPunch for Hardness and Nail Pull Resistance

FIG. 6 Test SetupÐSample Holder for Hardness Test

area 2 6 1¤2 in. (51 6 13  mm) from one edge of the  specimen, with the next two test areas spaced  approximately 4 in. (102 am) apart.  12.5.4 Condition specimens   in   accordance with   Section   5.   12.6

ProcedureÐUsing   the apparatus   in   12.3,  clamp or  secure the specimen in a  ®xed vertical position on  its 12 in. (305 mm)  dimension edge. If  necessary, modify the  ˉexural

strength   test   equipment   to conduct   the   core,   end,   and edge hardness test. Place this test surface not less than 1 in. (25 mm) above the grip of the specimen   holder.   After   the specimen is in place, zero the 7

load indicator. Conduct three tests spaced approximately 4 in.   (102   mm)   apart   on   each specimen,  with  the   ®rst  test area 2 6  1¤2 in. (51 6 13 mm) from   one   edge   of   the specimen.   Position   the   steel punch over the test area and apply

C 473 ± 03 the load. Report as the core, end, or edge hardness the load required to push the steel punch a distance of 1¤2  in. (13 mm) into the core of the specimen. 12.6.1  Procedure  for  Core  HardnessÐTest  either  of  the 12­in. (305­mm) saw cut edges, for a total of not less than nine tests (three per specimen). 12.6.2  Procedure for End HardnessÐTest the 12­in. (305­ mm) mill­cut end, for a total of not less than nine tests (three per specimen). 12.6.3  Procedure for Edge HardnessÐTest areas along the 12­in. (305­mm) edge, for a total of not less than eighteen tests (three per specimen). For products with surfacing material, test where the surfacing material has been removed. 12.7  ReportÐReport  the  core,  end,  and  edge  hardness individually as the average load in pounds­force or newtons rounded to the nearest 1 lbf (N). Discard any single test value that varies from the average by more than 15 % and repeat the test on the same sample to obtain a new value. 12.8  Precision and Bias: 12.8.1  PrecisionÐThe 95 % repeatability limit of the End Hardness (Method B) test is the test result 68.103 lbf [36.04 N].  The  95 %  reproducibility  limit  of  the  End  Hardness (Method B) test is the test result 69.725 lbf [43.56 N]. 12.8.2  PrecisionÐThe 95 % repeatability limit of the Core Hardness (Method B) test is the test result 64.231 lbf [18.82 N].  The  95 %  reproducibility  limit  of  the  Core  Hardness (Method B) test is the test result 69.668 lbf [43.01 N]. 12.8.3  PrecisionÐThe 95 % repeatability limit of the Edge Hardness (Method B) test is the test result 67.730 lbf [34.38 N].  The  95 %  reproducibility  limit  of  the  Edge  Hardness (Method B) test is the test result 623.031 lbf [102.45 N]. 12.8.4  BiasÐNo information can be presented on the bias of the procedure in these test methods for measuring the End, Core, and Edge Hardness because there is no material having an accepted reference value. 13. Nail Pull Resistance (Method B) 13.1  Summary of Test MethodÐThe ability of gypsum panel products to resist nail pull­through is evaluated by determining the load required to push a standard nail head through the product. 13.2  Signi®cance  and  UseÐThis  test  method  covers  a procedure for evaluating the ability of gypsum panel products to resist nail pull­through by determining the load required to force  a  standard  nail  head  through  the  product.  This  test method is used to determine compliance with gypsum panel product speci®cations. The degree of correlation between these test methods and service performance has not been determined. 13.3  ApparatusÐSee Section  10. The apparatus  shall  be used with either of the specimen support plates in 13.3.1 or 13.3.2. 13.3.1  Specimen Support Plate, shall be true and have a 3­in. (76­mm) diameter hole in the center. The support plate shall be not less than 6 by 6 in. (152 by 152 mm). It shall be attached to the apparatus as necessary to maintain the surface of the plate perpendicular to the travel of the test nail. The support plate must also be located so that the vertical axis through the center of the nail shank passes through the center of the hole in the support plate. The test nail shank shall be 8

0.099 6 0.003 in. (2.515 6 0.076 mm) in diameter and the nail head  shall  be  0.250  6 0.005  in.  (6.350  6 0.127  mm)  in diameter. The nail shall be attached at the head to the movable cross  head  of  the  test  apparatus. This  attachment  shall  not exceed  the  diameter  of  the  nail  head  and  shall  be  placed directly over the head. It shall also be attached so that the vertical axis through the nail shank is parallel with the travel. See Figs. 5 and 7 for examples of the test setup con®guration. 13.3.2  Fig. 3 shows a schematic of an alternate nail pull resistance apparatus adaptable to a typical ˉexural strength apparatus commonly used in the gypsum industry. This appa­ ratus mirrors all of the requirements of 13.3.1, except that the nail is not attached at the head to the movable cross head of the test  apparatus.  The  alternate  apparatus  utilizes  a  machined plunger  with  the  nail  head  and  shank  incorporated  as  an integral part of the plunger. The plunger ®ts into a bushing that keeps the nail aligned perpendicular to the test specimen. 13.4 SamplingÐSampling shall be in accordance with Sec­ tion 4. 13.5 Test Specimens: 13.5.1  Cut ®ve specimens 6 by 6 in. (152 by 152 mm) from a strip cut across the width of each 48­in. (1220­mm) gypsum panel product starting not less than 4 in. (102 mm) in from the edge. Cut a total of ®ve specimens from more than one full width strip from gypsum panel products less than 38 in. (965 mm) wide. Do not cut the specimen closer than 3 in. (76 mm) from the product edges. 13.5.2  Drill  a  7¤64­in.  (2.778­mm)  diameter  pilot  hole through the thickness of the gypsum panel product in the center of each test specimen and perpendicular to the surface. 13.5.3  Condition specimens in accordance with Section 5. 13.6 ProcedureÐUsing  the  apparatus  in  13.3,  place  the specimen on the specimen support plate so that the drilled hole is aligned with the nail shank tip. After the specimen is in place, zero the load indicator. Insert the nail shank into the specimen hole and apply the load until the maximum load is achieved. Normally, this will occur as the nail head breaks through the gypsum panel product surface and is followed by a very signi®cant decrease in load.

FIG. 7 Test SetupÐSample Holder for Nail Pull Resistance

C 473 ± 03 the 13.7Report Nail ÐCalc Pull ulate (Meth the od   B) averag test   is e the test maxim result um 65.610 load in lbf pound [24.95 s­force N]. or newto The  ns, 95 % rounde reprod d   to ucibili the ty nearest limit 1   lbf of   the (N). Nail Discar Pull d   any (Meth single od   B) test test   is that the varies test from result the 68.96 averag 1   lbf e   by [39.86 more N].  than 13.8.2 15   %. BiasÐNo If inform more ation than can be 15   % presen of   the ted   on test the values bias of are the discar proced ded, ure   in repeat these the test test.  metho 13.8Pre ds   for cisi measu on ring an Nail d Pull Bia becaus s:  e there is   no 13.8.1 materi PrecisionÐ al The   95 having % an repeata accept bility ed limit of

referen ce value. 

14.5.2  Condit ion  speci 14. H mens  u in  mi accord di ance  ® with  ed Sectio De n 5. ˉe 14.6Procedu cti reÐSusp end each on specime n   face down  on parallel and level bearing edges, having 1 ¤8­in. (3.2­ mm) radii,   12 in.   (305 mm) long, and   23 in.   (584 mm) apart   in the humidity cabinet in   an atmosph ere of 90 6  3°F (32  6 1.7°C) and 90 6 3   % relative humidity for 48 h. Measure the humidi® ed deˉectio n of each specime n,   while suspende d   on   the bearing edges, as the distance between a

straighte mm).  dge 14.7ReportÐ Report placed the on   the humidi® top   end ed edges   of deˉectio the n   as   the gypsum aver­age panel of   the specime product ns to the and   the nearest upper 1 ¤8 in. (3 surface mm).  of   the product 14.8Precisio n   and at   its BiasÐTh e center. precision Take and   bias measure­ of   this ments   to test the method has   not nearest been 1 ¤16  in. determin (1.6 ed.  high 14.1Summa humidit ry   of y for 48 Test h.  Method ÐThe 14.2Signi® cance humidi and ®ed UseÐT deˉectio his   test n  of method gypsum covers a panel procedu product re   for s   is evaluati evaluat ng   the ed   by deˉectio supporti n   of ng   a speci­ gypsum men panel that   has product been s   when cut with horizon the long tally dimensi suspend on ed   and perpend subjecte icular d   to to   the high machin humidit e y.   This directio test n, method support is   used ed to horizon determi tally, ne and complia subjecte nce d   to with

gypsum panel product speci®c ations. Since job factors other than high humidit y inˉuenc e   the deˉectio n   of gypsum panel product s,   the degree of correlat ion betwee n   this test method and service perform ance has   not been determi ned.  14.3Appara tusÐA humidit y cabinet of sufficie nt   size to accom modate test specime ns   12 by   24 in. (305 by   610 mm) capable of maintai ning   an atmosp here   of 90  6 3°F   (32

6 1.7°C) and   90 6  3   % relative humidit y for 48 h.  14.4S a m p l i n g Ð S a m p l i n g   s h a l l   b e   i n   a c c o r d a n c e   w i t h   S e c ­   tion 4.  14.5T e s

t   S p e c i m e n s :   14.5. 1   Cut two specime ns   12 by   24 in. (305 by   610 mm) from each gypsum panel product in   the sample so   the 12­in. dimensi on   is parallel to   the edges. Cut specime ns   not less than 12­in. away from the ends and edges of gypsum panel product s 48 in. (1220 mm)   or more   in width. Cut specime ns   from the center of

gypsum panel product s   that are narrowe r   than 48   in. (1220 mm)   as noted in Fig. 8.

is   used to determi ne complia nce with 15.1 Summar gypsum y   of panel Test product Method speci®c ations. ÐThe The end degree squaren of ess   of correlat gypsum ion panel betwee products n   this is test evaluate method d   by and drawing service a   line perform perpen­ ance dicular has   not to   the been edge   of determi a   full ned.  width 15.3Appara specime tusÐA n   to   its T­ opposite shaped edge or   L­ and shaped measuri square ng   the for length draw­ of   the ing   or side   of testing right the angles. triangle The formed.  long 15.2Signi® edge   of cance the and square UseÐT shall   be his   test not   less method than   48 covers in.  a 15.4S procedu a re   for m determi p ning the l end i squaren n ess   of g gypsum Ð panel S product a s.   This test m method p 15. En d Sq uar ene ss 

l ˉush against i n the g edge   of the   gypsum s panel h product a with the l apex   of l the square   b at   one e corner of   the   product i . n Determi   ne   the a distance c b, to the c nearest o 1¤16  in. r (1.6 d mm)   at a the n speci®e c d e distance a.   Distanc w e   is i measur t ed from h the apex   of   S the e square c (see Fig. 9).  ­ 15.7Report   ÐRepor tion 4.  t   the 15.5Test average Specim of ensÐUs distance e   full­ b  to the size nearest gypsum 1 panel ¤8  in. product (3.2 s  with mm).  undama 15.8Precisi ged on   and ends for BiasÐT he test precisio specime n   and ns.  bias   of 15.6Proced this   test method ureÐPl has   not ace   one been edge   of determi the ned.  square

FIG. 8 Sample Selection Detail for Humidi®ed De¯ection Test 9

C 473 ± 03 product s, and is used   to determi ne complia nce FIG. 9with End gypsum Squarpanel enessproduct Deterspeci®c minatations. ion The degree of 16. Thi correlat ck ion nes betwee s  n   this 16.1Summa test ry   of method Test and Method service ÐThe perform nomina ance l has   not thickne been ss   of deter­ gypsum mined.  panel 16.3 Apparat product usÐA s   is microm evaluat eter ed   by gage for measuri determi ng   the ning the thickne thicknes ss   of s the measure specim ment   to en   with 0.001 a in. microm (0.025 eter.  mm). 16.2Signi® The cance microm and e­ter UseÐT shall   be his   test a   1­in. method (25.4­ covers mm) a hand procedu microm re   for eter determi with 1 ning the ¤4­in. thickne (6.35­ ss   of mm) gypsum diamete panel r   anvils

graduat ed   to 0.01   in. (0.25 mm). 

p e c i m e n s :  

16.4S a m p l i 16.5.1 n Use g ful Ð l­ S siz a e m gy p ps l u i m n pa g ne   l s pr h od a uc l ts l fo   r b tes e t sp   i ec n i­  mens.    a16.5.2 cMark   the c product o to   be tested, r d score a on   both n sides, c and e break at 12   in.   w (305 mm) i from t h each end,   S discardi e ng   the two c ends ­ prior   to   testing. tion 4.  Retain 16.5T the e remaini s ng   part t of   each   gypsum S

panel product as a test specim en.  16.6 Proced ureÐMa rk measure ment points at approxi­ mately equal points across the width at each end   of the gypsum panel product excludi ng   the tapered, beveled, or recessed edges   if applicab le. Engage the microm eter ®rmly, but   do not indent the surfacin g material of   the gypsum panel product. Measur e   the thicknes s   of   the gypsum panel product with the microm eter   not less than  1¤2 in.   (13

mm) from cut ends. Take   a minimu m of not less than seven readings at   each end   of the   54­ in. (1370­ mm) wide gypsum panel product, six readings at   each end   of the   48­ in. (1220­ mm) wide gypsum panel product, ®ve readings at   each end   of the   32­ in. (813­ mm) wide gypsum panel product, four readings at   each end   of the   24­ in. (610­ mm) wide gypsum panel product, or   three readings at   each end   of the   16­ in. (406­

mm) wide gypsum panel product.

16.7 Report ÐCalcu late   the nomina l thickne ss   of each specim en   as the average of   the individ ual microm eter reading taken on each gypsum panel product . Calcula te   and report the sample thickne ss   as the average measur ed thickne ss of all the specim ens   in the sample to   the nearest 1 ¤64  in. (0.4 mm) and local variatio ns   in any one specim en   to the nearest 1 ¤32  in. (0.8 mm).  16.8 Precisi

on   and BiasÐT he precisio n   and bias   of this test method has   not been determi ned.  17. Re ces sed ­ or Ta per ed­ Ed ge De pth 17.1  Summa ry of  Test  Method ÐThe  recesse d­ or  tapered ­edge  depth  of  gypsum panel  product s is  evaluat ed by  compar ­

mance ing the  has   not thickne been ss near  determi the  ned.  edge of 17.3A the  p specim p en to  a the  r thickne ss in  a the  t ®eld of u the  s specim Ð en. U 17.2Signi® s cance e and    UseÐT t his   test h method e provide    s   a m proced i ure   for c determi r ning o the m depth e of   the t recess e or taper r on   the    edge   of g gypsum a panel g product e s   board    and   is d used   to e determi s ne c compli r ance i with b gypsum e panel d product speci®    ca­ i tions. n The   degree 16.3. E of ngage correlat the ion microm betwee eter n   this ®rmly test but   do method not and indent service the perfor surfaci

ng c materia ­ l.   Take   all tion 4.  reading 17.5Spe s to the cim nearest ens 0.001 :  in. 17.5.1 (0.025 Use   the mm)   of same specim specim en ens thickne prepare ss.  d   in 17.4S 16.5, or a prepare m another p set   of specim l ens   as i n indicate g d   in Ð 16.5.  17.6 S Proc a edure m :  p 17.6.1 l At   one i co n rn g er,   de s ter h mi a ne l th l e   thi b ck e ne   ss i 6 n in.   (1 a 52 c am) fr c o o m r th d e a cu n t c en e d   an w d i 3 ¤ t 8 h in.   (9. S 5 e

m ­edge depths, m as   in ) 17.5.  fr o 17.6.5 m Determine the th variatio e n   of ed any ge individ .  ual 17.6.2 recesse Subtract  the d   or specim en   as tapered determi ­edge ned   in depth 17.6.1 from from the the average average specim as en determi thickne ss   as ned   in determi 17.6.4 ned   in using Section the 16.  subtract 17.6.3 ion Repeat   the method proced .  ure   in 17.6.1 17.6.6 Reject   or and discard 17.6.2 any on   the individ remaini ual ng recesse three d­   or corners tapered of   this ­edge specim depth en   and calculat on   the ion,   as remaini in ng   two 17.6.2, specim if   the ens   of variatio the n   from sample. average 17.6.4 ,   as   in Determine 17.6.5, the exceeds average 0.050 recesse in. d   or (1.27 tapered mm). ­edge To depth constitu from te   a all   the valid individ test   do ual not recesse discard d   or more tapered

than ed   by three measuri individ ng   the ual edge­ calculat to­edge ions.  dimen­ sion   of 17.7 a   full Report size ÐRepor specim t   the en.  average recesse 18.2 Signi®c d­   or ance tapered and ­edge UseÐTh depth is   test as   in method 17.6.4 provides after a any procedu adjustm re   for ents for determi exclusi ning   the ons   of width of data   as gypsum in panel 17.6.5 products or and   is 17.6.6 used   to to   the determi nearest ne 0.001 complia in. nce with (0.025 gypsum mm).  panel 17.8 products Precisi speci®c on   and ations. BiasÐT he The precisio degree n   and of bias   of correlati this test on method between has   not this   test been method determi and ned.  18. Wi dth

service perform ance has not been determi ned. 

18.1Summa ry   of Test Method 18.3Appara tusÐAn ÐThe y width accurat of e gypsum measuri panel product ng s   is device evaluat capable

of r d measuri a n ng   the c e width   of   the w i gypsum t h panel   product S e to   the c ­ nearest   1 ¤32  in. tion 4. (1 18.5Test mm).  Specim 18.4S ensÐUs a e   full­ m p size l gypsum i n panel g Ð product S s  for a m test p specim l i n ens.  g 18.6P   r s h o a l c l e   b d e u   i r n   e a : c c   o 10

C 473 ± 03 round, 18.6.1 determi Measure the ne   the width overall of   an distanc individ e.   One ual excepti gypsum on   is panel tongue product and by groove placing edge the specim measuri ens,   the ng width device of perpend which icular is   the to   the distanc edges e of   the betwee gypsum n   the panel rip   of product the when tongue measur and   the ements bottom are of   the taken. groove. The 18.6.2 width of   theThe   width of   an specim individ en   is ual the gypsum distanc panel e product betwee is   the n maxim extremi um   of ties   of two the reading edges, s   taken so   in not   less cases than   48 where in. the (1220  edge   oram) apart edges and are about   6 beveled in. (152 (slope mm) in   or away out) from with the both face   or ends   of back   of the specim the en.   Cut specim off 6 in. en,   or (152 are

mm) measuri from ng   the both end­to­ ends end before dimensi taking on   of   a measur full size ements specim at   ends en.  of 19.2 Signi®c tongue ance and and groove­ UseÐTh edge is   test specim method ens.  provide 18.7 s   a Report procedu ÐRepor re   for t   the determi width ning the as   the length average gypsum width panel of   not product less s   and   is than used   to three determi specim ne ens   to complia the nce with nearest gypsum 1 panel ¤32  in. product (1 mm). s 18.8 Precisi speci®c on   and ations. BiasÐT The he degree precisio n   and of bias   of correlati this test on method has   not between been this   test determi method ned.  19. Le ngt h 

and service perform ance has not been determi ned. 

19.1Summa ry   of Test Method 19.3Appara tusÐAn ÐThe y length accurat of e gypsum measuri panel ng product device s   is capable evaluat of ed   by

measuri r e ng   the : width   of   the gypsum 19.6.1 panel Measure the length product of   an to   the individ nearest 1 ual ¤16  in. gypsum (2 mm). panel 19.4S a product m by p l placing i n the g measuri Ð S ng a m device p parallel l with the i n edges g when   s h measur ements a l are l   taken. b The e   length i n of   the   specim a en   is c c o the r distanc d e a n betwee c n e   w extremi ties   of i t h the   ends, so S in cases e c where ­ the   tion 4. ends are 19.5Test beveled Specim ensÐUs , e   full­ determi size ne   the gypsum overall panel distanc product e.  s  for19.6.2 test The   length specim of   a ens.  specim 19.6P en   is r the o maxim c um   of e two d reading u s   taken

about   3 in.   (76 mm) away from both edges of   the specim en.  19.7Report ÐRepor t   the length as   the average length of   not less than three specim ens   to the nearest 1 ¤8  in. (3 mm). 19.8Precisi on   and BiasÐT he precisio n   and bias   of this test method has   not been determi ned. 

r e ­ T r e a t e d   W a t e r ­ R e p e l l e n t   G y p s u m   P a n e l   P r o d u c t s  

20. W a t e r   R e s i s t a n 20.1Summa ry   of c Test e Method   ÐThe o water f resistan   ce   of C core­ o treated

water­ 20.2Signi® repellen cance t and gypsum UseÐT panel his   test product method s   is provide evalu­ s   a ated   by procedu immers re   for ing   the evaluati specim ng   the en   in ability water of core­ for   the treated speci®e gypsum d panel period product of time. s   to

resist water penetrat ion. This test method is   used to determi ne complia nce with gypsum panel product speci®c ations. The degree of correlat ion betwee n   this test method and service perform ance has   not been determi ned.  20.3A p p a r a t u

by   12­ in. (305 by   305­ mm) 20.3.1 test Water   Bath, speci­ not   less men cut than   16 from by   16 the by 3 in. center (406   by of   the 406   by gypsum 75 mm) panel capable product of being maintai tested ning the by water at scoring a and constan breakin t g.   Cut tempera specime ture   of ns 70  6 approxi 1°F   (21 mately 6 centere 0.5°C).  d 20.3.2 betwee Glass   Rods, n   both 0.25   in. edges (6   mm) and   not in less diamete than   6 r,   or in. (152 other mm) support from s either capable end. Do of not keeping treat the the edges specime of   the ns   off specime the n   nor bottom damage of   the any water surfacin bath.  g 20.4 material Sampli .  ngÐSa mpling 20.5.2 shall   beCondition the in specime accorda ns   in nce accorda with nce Sec­ with tion 4.  Section 20.5 5, Test except Speci at   a mens: tempera 20.5.1 ture   of Prepare a 12 s :  

70  6 5°F   (21 6  2°C), and then weigh to within 0.5 g.  20.6 Proc edure :  20.6.1 Position   the specime n so that it   rests ˉatwise on   glass rods   or other supports in   the water bath with   a head   of 1 in. (25

am) of water over the top   of the specime n. If the specime n   ˉoats, place sufficie nt weight on   the specime n   to keep   it in contact with the support s   under the   1­ in.   (25­ mm) head   of water.  20.6.2 After   2   h have elapsed, remove the specime

n   from the bath, wipe excess water from the surfaces and edges of   the specime n   and weigh immedi ately   to within 0.5 g.  20.7 Report ÐCalcu late   the gain   in weight for each speci­ men   as a percent age   of the original weight as determi ned   in 20.5.2 to   the nearest 1 % and report the average percent age   as the water absorpti on   of the gypsum panel product .  20.8 Precisi on   and BiasÐT he precisio n   and bias   of this   test

method has   not been determi ned. 

surfaces is evaluat ed   by dammin g   a 21. Su speci®e d   area rf on   the ac treated e surface, W ®lling at that er area Re with sis water, ta and nc allowin g   it   to e remain of undistur G bed   for yp the su speci®e m d   time Pa period.  ne 21.2Signi® l cance Pr and od UseÐT his   test uc method ts provide wi s   a th procedu W re   for at evaluati er ng   the ­ ability Re of pe water­ lle repellen nt t Su surfac­ ing   of rf gypsum ac panel es  product 21.1Summa s   to ry   of resist Test water Method penetrat ÐThe ion. surface This water test resis­ method tance of is   used gypsum to panel determi product ne s   with complia water­ nce repellen with t

gypsum ance panel has   not product been speci®c deter­ ations. mined.  The 21.3Appara degree tusÐA of Cobb correlat Tester ion conditio betwee ned to a n   this tempera ­ture   of test 70  6 method 5°F   (21 and 6 service 0.5°C).  perform 11

C 473 ± 03 NOTE 2ÐFor   a descripti on of the test apparatus see   Test Method D   3285. The studs that anchor the metal crossbar may need to   be lengthen ed   to accomm odate gypsum panel products.

e   w i t h   S e c ­  

tion 4.  21.5T e s t   S p e 21.4S c a i m m p e l n i s n : g   Ð 21.5.1 S aCut   three specime m ns 5 in. p (127 l mm) i square n from g the   ®eld   of s each h sample a piece of l gypsum l panel product.   b21.5.2 eCondition the   specime i n ns   in accorda   a nce c with c Section o 5, except r d at   a a tempera n ture   of  6 c 70

5°F   (21 21.6. 6  2°C), 2   After to 2   h constan have t weight elapsed within ,   pour 0.1   % the and water then out   of weigh the to Cobb within ring 0.05 g.  and 21.6 remove Proc the edure specim :  en from 21.6.1 the Place   the Cobb conditio Tester. ned   test Immedi specime ately ns   in remove the excess Cobb water Tester from with the the side   to specim be en   by exposed blotting to water and facing weigh up.   Fill to   the the nearest Cobb 0.05 g. ring with tap21.7Report water ÐCalcu adjuste late d   to   a average tempera differen ture   of ce 70  6 betwee 1°F   (21 n   the 6 dry  and 0.5°C), wet resultin weights g i n a 1 of   the in. test (25.4 specime mm) ns   to head   of the water nearest above 0.1   g the   test and area   of report the this   as specime the n.  surface water absorpti on   of the

gypsum panel product .  21.8Precisi on   and BiasÐT he precisio n   and bias   of this test method has   not been determi ned.  22. Ke yw ord s  22.1absorpt ion testing; core hardnes

s testing; dimensi on measur ements; edge hardnes s testing; end hardnes s testing; ˉexural strengt h; gypsum panel product s; humidi ®ed sag; nail pull testing 

APPENDIXE S (Nonmandatory  Information) X1.  INTRODUCTION

X1.1  ASTM  speci®c ations  for  gypsum  panel  products do not  contain  a  speci®c ation for weight.  The  procedu re,  however ,

is  referenc ed in  other  industry standar ds, and  is  therefor e  retained as an  appendi x item.

X2. WEIGHT

X2.1

Test Specim ensÐA sample shall consist of   not less than three full size pieces of   the gypsum panel product . X2.2 Proced ureÐM easure the length and width of   each specime n   in accorda nce with Section s   17 and   18. Weight the specime ns   on   a suitable scale and record the weight to   the nearest 1 ¤4  lb (0.1 kg). X2.3 Calcula tionÐC alculate the weight in accorda nce

with the followi ng equatio n   and table:

weight as   the average calculat Where: Meaning of Symbol ed W = weight of specimen weight, L = length of specimen in B = width of specimen lb/1000 P = weight of specimen ft2(kg/1 K = 00   m2) of   the X2.4 three Report gypsum ÐRepor specime t   the ns.

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C 473 ± 03 SUMMARY OF CHANGES Committee C11 has identi®ed the location of selected changes to this standard since the last issue (C 473 ±  00) that may impact the use of this standard. (Approved June 10, 2003.) (1) Added Precision and Bias information in sections 11.8, 12.8, and 13.8.

(2) Revised section 20.3.1.

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