|Accessories for gypsum board||ASTM C 1047|
|Adhesives for fastening gypsum wallboard||ASTM C 557|
|Elastomeric joint sealants||ASTM C 920|
|Fiber-reinforced gypsum panels||ASTM C 1278|
|Glass mat gypsum backing panel||ASTM C 1178|
|Glass mat gypsum panel||ASTM C 1658|
|Glass mat gypsum substrate||ASTM C 1177|
|Joint reinforcing tape and compound||ASTM C 474; C 475|
|Nails FOR gypsum boards||ASTM C 514, |
F 547, F 1667
|Steel screws||ASTM C 954; C 1002|
|Steel studs, load-bearing||ASTM C 955|
|Steel studs, nonload-bearing||ASTM C 645|
|Standard specification for gypsum board||ASTM C 1396|
|Testing gypsum and gypsum products||ASTM C 22; C 472; |
LATH, PLASTERING MATERIALS AND ACCESSORIES
|Accessories for gypsum veneer base||ASTM C 1047|
|Blended cement||ASTM C 595|
|Exterior plaster bonding compounds||ASTM C 932|
|Gypsum casting and molding plaster||ASTM C 59|
|Gypsum Keene's cement||ASTM C 61|
|Gypsum plaster||ASTM C 28|
|Gypsum veneer plaster||ASTM C 587|
|Interior bonding compounds, gypsum||ASTM C 631|
|Lime plasters||ASTM C 5; C 206|
|Masonry cement||ASTM C 91|
|Metal lath||ASTM C 847|
|Sand||ASTM C 35; C 897|
|Perlite||ASTM C 35|
|Vermiculite||ASTM C 35|
|Plastic cement||ASTM C 1328|
|Portland cement||ASTM C 150|
|Steel screws||ASTM C 1002; C 954|
|Steel studs and track||ASTM C 645; C 955|
|Welded wire lath||ASTM C 933|
|Woven wire plaster base||ASTM C 1032|
Gypsum board and gypsum plaster construction shall be of the materials listed in Tables 2506.2 and 2507.2. These materials shall be assembled and installed in compliance with the appropriate standards listed in Tables 2508.1 and 2511.1.1, and Chapter 35.
INSTALLATION OF GYPSUM CONSTRUCTION
|Gypsum board||GA-216; ASTM C 840|
|Gypsum sheathing||ASTM C 1280|
|Gypsum veneer base||ASTM C 844|
|Interior lathing and furring||ASTM C 841|
|Steel framing for gypsum boards||ASTM C 754; C 1007|
- Where the gypsum board is to receive a decorative finish such as wood paneling, battens, acoustical finishes or any similar application that would be equivalent to joint treatment.
- On single-layer systems where joints occur over wood framing members.
- Square edge or tongue-and-groove edge gypsum board (V-edge), gypsum backing board or gypsum sheathing.
- On multilayer systems where the joints of adjacent layers are offset from one to another.
- Assemblies tested without joint treatment.
|MATERIAL||THICKNESS OF MATERIAL (MINIMUM) (inches)||SPACING OF FRAMING |
|SHEAR VALUEa, b |
(plf of ceiling)
|MIMIMUM FASTENER SIZE|
|Gypsum board||1/2||16 o.c.||90||5d cooler or wallboard nail; |
15/8-inch long; 0.086-inch shank;
|Gypsum board||1/2||24 o.c.||70||5d cooler or wallboard nail; |
15/8-inch long; 0.086-inch shank;
- Values are not cumulative with other horizontal diaphragm values and are for short-term loading due to wind or seismic loading. Values shall be reduced 25 percent for normal loading.
- Values shall be reduced 50 percent in Seismic Design Categories D, E and F.
- 11/4-inch, No. 6 Type S or W screws are permitted to be substituted for the listed nails.
Water-resistant gypsum backing board shall not be used in the following locations:
- Over a vapor retarder in shower or bathtub compartments.
- Where there will be direct exposure to water or in areas subject to continuous high humidity.
- On ceilings where frame spacing exceeds 12 inches (305 mm) o.c. for 1/2-inch thick (12.7 mm) water-resistant gypsum backing board and more than 16 inches (406 mm) o.c. for 5/8-inch thick (15.9 mm) water-resistant gypsum backing board.
- On horizontal supports of ceilings or roof soffits.
- On interior walls.
Water-resistive barriers shall be installed as required in Section 1404.2 and, where applied over wood-based sheathing, shall include a water-resistive vapor-permeable barrier with a performance at least equivalent to two layers of Grade D paper. The individual layers shall be installed independently such that each layer provides a separate continuous plane and any flashing (installed in accordance with Section 1405.4) intended to drain to the water-resistive barrier is directed between the layers.
Plastering gypsum plaster or cement plaster shall not be less than three coats where applied over metal lath or wire fabric lath and not less than two coats where applied over other bases permitted by this chapter.
INSTALLATION OF PLASTER CONSTRUCTION
|Cement plaster||ASTM C 926|
|Gypsum plaster||ASTM C 842|
|Gypsum veneer plaster||ASTM C 843|
|Interior lathing and furring |
|ASTM C 841|
|Lathing and furring (cement plaster)||ASTM C 1063|
|Steel framing||ASTM C 754; C 1007|
|COAT||MINIMUM PERIOD MOIST CURING||MINIMUM INTERVAL BETWEEN COATS|
|First||48 hoursa||48 hoursb|
|Second||48 hours||7 daysc|
- The first two coats shall be as required for the first coats of exterior plaster, except that the moist-curing time period between the first and second coats shall not be less than 24 hours. Moist curing shall not be required where job and weather conditions are favorable to the retention of moisture in the cement plaster for the required time period.
- Twenty-four-hour minimum interval between coats of interior cement plaster. For alternative method of application, see Section 2512.8.
- Finish coat plaster is permitted to be applied to interior cement plaster base coats after a 48-hour period.