1. Should I be concerned with recent media reports of wallboard imported from China if I use PABCO® Gypsum products?
There’s no need for concern if the products you use (or have used in the past) are from PABCO® Gypsum – PABCO’s wallboard products are manufactured in accordance to ASTM C1396,
Standard Specification for Gypsum Board. Please see the below document links for letters of compliance and industry responses.
PABCO® Gypsum Letter of Compliance (pdf)
GYPSUM ASSOCIATION Response (pdf)
2. What is ASTM C 1396?
ASTM C 1396 is the new "Standard Specification for Gypsum Board." Instead of having a different designation for each type of gypsum board as before, C 1396 is the Standard that includes Gypsum Sheathing, Water Resistant Gypsum Backing Board, Gypsum Soffit Board, and other types of gypsum board. For example, ASTM C 79 which was the Standard Specification for Gypsum Sheathing is now incorporated into ASTM C 1396.
3. I am considering using a gypsum board system that calls for the use of nails as mechanical fasteners. Can Screws be substituted for nails?
Yes. As long as the spacing is the same and the length of screw, head diameter, and shank are the same or longer then screws may be substituted for nails.
4. When constructing a fire rated wall, is it necessary to use wood or steel studs that are exactly the same dimension as those mentioned in the tested design?
No. Wood or Steel studs dimensions are minimums unless otherwise noted. If a 2 1/2" stud is called for a 3 5/8" stud may be used.
5. The system I am installing calls for "cooler" nails. I am having trouble finding this type of nail in my area. Can I substitute another type of nail for cooler nails?
Yes. Any nail with a length, shank diameter, and head diameter equal to or greater than the dimension specified may be substituted.
6. Does gypsum board have an "R" Value?
Yes. The R Value's of gypsum board are as follows:
7. Is it necessary to tape the joints in the base layers of fire rated multi - layered gypsum board systems to maintain the fire rating?
No. In multi layer systems the joints and fasteners in the base layers are covered and protected by the overlying layers of gypsum board.
8. Is gypsum board considered to be a non-combustible material by the building codes?
Due to the unique properties of the gypsum core, gypsum board is widely used in fore resistant rated construction. Model building codes, including the International Building Code consider composite building materials such as gypsum board to be non combustible if:
- The core of the material passes ASTM E 136
- The material surfacing is not more than 1/8"
- The composite material has a flame spread rating of not greater than 50 when tested in accordance with ASTM E 84.
Gypsum board meets these three criteria and therefore is considered to be non combustible.
NOTE: a slightly different definition is contained in NFPA 5000, Building Construction and Safety Code.
9. Can water resistant gypsum backing board (green board) be applied to ceilings?
Under certain conditions, water resistant backing board can be applied to ceilings. 1/2" water resistant backing board may be applied when the framing does not exceed 12" o.c. and 5/8" water resistant gypsum backing board may be applied when framing does not exceed 16" o.c.
10. What are the Levels of Gypsum Board Finish?
This recommended specification describes various levels of finish of gypsum board surfaces prior to the application of paint or final decoration. The recommended level of finish of gypsum board wall and ceiling surfaces varies with the final decoration to be applied and can be dependant on their location in a structure and the type of illumination striking the surface. For more information please see Gypsum Association document GA 214.
11. Do special precautions need to be taken when applying gypsum board during winter weather conditions?
Yes. When applying gypsum board in any extreme weather condition it is necessary to take precautions to insure a positive outcome. Recommendation include but are not limited to:
- Room temperatures shall be maintained at not less than 40 Degrees F. during the installation of gypsum board.
- For the bonding of adhesive, joint treatment, texturing, and decoration, the room temperature shall be maintained at not less than 50 Degrees F. for 48 hours prior to application and continuously thereafter until completely dry.
- When a temporary heat source is used the temperature shall not exceed 95 Degrees F .in any given room or area.
- Adequate ventilation shall be maintained in the working area during installation.
- Gypsum board shall be protected from direct exposure to rain, snow, sunlight, or other excessive weather conditions.
- For more information please see Gypsum Association GA 216 and ASTM C 840.
12. When gypsum board is transported and covered by plastic bags can the board be stored outside or in the case of excessive weather conditions can gypsum board be stored without removing the plastic?
No. Plastic bags may be used during transportation but should be immediately removed and the gypsum board stored in an appropriate weather resistant location until placed in the structure where the gypsum board will be applied.
