Gypsum Wallboard (Drywall)

Gypsum wallboardGypsum wallboard is not required throughout a dwelling however it is widely used as an interior finishing material. Gypsum wallboard is required:

  • on the garage side of the wall between the house and garage.
  • in enclosed accessible space under stairs.
  • on a wall of a building less than 3 feet from a property line.
  • for separations between dwelling units where two or more dwellings exist in the same building.

Application

  • Gypsum board may not be installed until adequate weather protection is provided. Gypsum wallboard intended for interior use may not be used in areas exposed to the weather.
  • Interior non-bearing studs may be 2 x 3 studs spaced not more than 24" on center (OC). Exterior or bearing walls must be 2 x 4 minimum and spaced not more than 24" OC.
  • Other framing supporting gypsum board, such as for soffits or furring, may be 2 x 2 material. If the furring is applied against a solid backing such as foam sheathing on a foundation wall, it may be 1 x 2 material.
  • All edges and ends of gypsum wallboard must occur on framing members except those edges and ends that are perpendicular to framing members. All edges and ends of gypsum wallboard should be in moderate contact except in concealed spaces where fire resistive construction or diaphragm action is not required.

Fasteners

Nails used to fasten gypsum wallboard must conform to Table R702.3.5 of the International Residential Code. Screws must be approved for drywall application. Nails or screws used to anchor gypsum wallboard should not break the facing paper.

3/8 inch Gypsum Board
Application Orientation to framing Maximum spacing
of framing members		 Maximum spacing
of fasteners
Nails* Screws
Ceiling Perpendicular 16" OC 7" 12"
Wall Either direction 16" OC 8" 16"
Size of fasteners for application of
gypsum board to wood framing
Nails: 13 gage, 1 1/4" long, 19/64" head; 0.098 diameter, 1 1/4" long, annular-ringed; or 4d cooler nail, 0.080" diameter, 1 3/8" long, 7/32" head.
Screws: Type S or W and penetrate into wood framing a minimum of 5/8". Minimum screw length 1".
1/2 inch Gypsum Board
Application Orientation to framing Maximum spacing
of framing members		 Maximum spacing
of fasteners
Nails* Screws
Ceiling Either direction 16" OC 7" 12"
Ceiling Either direction 24" OC 7" 12"
Wall Either direction 24" OC 8" 12"
Wall Either direction 16" OC 8" 16"
Size of fasteners for application of gypsum board to wood framing
Nails: 13 gage, 1 3/8" long, 19/64" head; 0.098 diameter, 1 1/4" long, annular-ringed; 5d cooler nail, 0.086" diameter, 1 5/8" long, 15/64" head; or gypsum board nail, 0.086" diameter, 1 5/8" long, 9/32" head.
Screws: Type S or W and penetrate into wood framing a minimum of 5/8". Minimum screw length 1 1/8".
5/8 inch Gypsum Board
Application Orientation to framing Maximum spacing
of framing members		 Maximum spacing
of fasteners
Nails* Screws
Ceiling Either direction 16" OC 7" 12"
Ceiling Perpendicular 24" OC 7" 12"
Wall Either direction 24" OC 8" 12"
Wall Either direction 16" OC 8" 16"
Size of fasteners for application of gypsum board to wood framing
Nails: 13 gage, 1 5/8" long, 19/64" head; 0.098 diameter, 1 3/8" long, annular-ringed; 6d cooler nail, 0.092" diameter, 1 7/8" long, 1/4" head; or gypsum board nail, 0.0915" diameter, 1 1/8" long, 19/64" head.
Screws: Type S or W and penetrate into wood framing a minimum of 5/8". Minimum screw length 1 1/4".

* A pair of nails spaced 2 to 2 ½ inches apart may be used with the pair of nails spaced 12 inches on center.

Special rules for ceilings

You can not use 3/8" gypsum board on a ceiling in either of the following situations:

  • where a water-based textured finish is to be applied.
  • where it will be required to support insulation above a ceiling.

On ceiling applications that will receive a hand or spray applied water-based textured finish:

  • gypsum board must be applied perpendicular to the framing.
  • 1/2" gypsum board must be used for 16" OC framing.
  • 5/8" gypsum board must be used for 24" OC framing (½" sag-resistant gypsum ceiling board may be used as an alternate).

Moisture resistant gypsum board

Regular gypsum wallboard may not be used as a backer for tile or wall panels for tubs or showers. Moisture resistant gypsum board or other approved materials must be used in these locations.

Moisture resistant gypsum board may not be used in the following locations:

  • Over a vapor retarder
  • In areas subject to continuous high humidity such as saunas or steam rooms
  • On ceilings where frame spacing exceeds 12" for 1/2" gypsum board and 16" for 5/8" gypsum board

All cut or exposed edges, including those at wall intersections, must be sealed as recommended by the manufacturer.

Contacts

  • Inspections & Fire Secretary

    952-548-6320