Section R702 Interior Covering
Interior coverings or wall finishes shall be installed in accordance with this chapter and Table R702.1(1), Table R702.1(2), Table R702.1(3) and Table R702.3.5. Interior masonry veneer shall comply with the requirements of Section R703.7.1 for support and Section R703.7.4 for anchorage, except an airspace is not required. Interior finishes and materials shall conform to the flame spread and smoke-development requirements of Section R302.9.
THICKNESS OF PLASTER
|PLASTER BASE||FINISHED THICKNESS OF PLASTER FROM FACE OF LATH, MASONRY, CONCRETE (inches)|
|Gypsum Plaster||Cement Plaster|
|Expanded metal lath||5/8, minimuma||5/8, minimuma|
|Wire lath||5/8, minimuma||3/4, minimum (interior)b|
|7/8, minimum (exterior)b|
|Gypsum lathg||1/2, minimum||3/4, minimum (interior)b|
|Masonry wallsc||1/2, minimum||1/2, minimum|
|Monolithic concrete wallsc, d||5/8, maximum||7/8, maximum|
|Monolithic concrete ceilingsc, d||3/8, maximume||1/2, maximum|
|Gypsum veneer basef, g||1/16, minimum||3/4, minimum (interior)b|
|Gypsum sheathingg||—||3/4, minimum (interior)b|
|7/8, minimum (exterior)b|
For SI: 1 inch = 25.4 mm.
- Where measured from back plane of expanded metal lath, exclusive of ribs, or self-furring lath, plaster thickness shall be 3/4 inch minimum.
- Where measured from face of support or backing.
- Because masonry and concrete surfaces vary in plane, thickness of plaster need not be uniform.
- Where applied over a liquid bonding agent, finish coat shall be permitted to be applied directly to concrete surface.
- Approved acoustical plaster shall be permitted to be applied directly to concrete or over base coat plaster, beyond the maximum plaster thickness shown.
- Attachment shall be in accordance with Table R702.3.5.
- Where gypsum board is used as a base for cement plaster, a water-resistive barrier complying with Section R703.2 shall be provided.
GYPSUM PLASTER PROPORTIONSa
|NUMBER||COAT||PLASTER BASE OR LATH||MAXIMUM VOLUME AGGREGATE PER 100 POUNDS NEAT PLASTERb|
|Damp Loose Sanda||Perlite or Vermiculitec|
|Two-coat work||Base coat||Gypsum lath||2.5||2|
|Three-coat work||First coat||Lath||2d||2|
|First and second coats||Masonry||3||3|
For SI: 1 inch = 25.4 mm, 1 cubic foot = 0.0283 m3, 1 pound = 0.454 kg.
- Wood-fibered gypsum plaster shall be mixed in the proportions of 100 pounds of gypsum to not more than 1 cubic foot of sand where applied on masonry or concrete.
- Where determining the amount of aggregate in set plaster, a tolerance of 10 percent shall be allowed.
- Combinations of sand and lightweight aggregate shall be permitted to be used, provided the volume and weight relationship of the combined aggregate to gypsum plaster is maintained.
- If used for both first and second coats, the volume of aggregate shall be permitted to be 2.5 cubic feet.
- Where plaster is 1 inch or more in total thickness, the proportions for the second coat may be increased to 3 cubic feet.
CEMENT PLASTER PROPORTIONS, PARTS BY VOLUME
|CEMENTITIOUS MATERIALS||VOLUME OF|
SUM OF SEPARATE
Type I, II or III;
Cement Type IP,
I (S < 70), IL, or
IT (S < 70); or Hydraulic
Cement Type GU, HE,
MS, HS or MH
Type M, S or N
|First||Portland or blended||1||—||—||3/4 - 11/2a||21/2 - 4|
|Masonry||—||1||—||21/2 - 4|
|Plastic||—||1||—||—||21/2 - 4|
|Second||Portland or blended||1||—||—||3/4 - 11/2||3 - 5|
|Masonry||—||1||—||3 - 5|
|Plastic||—||1||—||—||3 - 5|
|Finish||Portland or blended||1||—||—||11/2 - 2||11/2 - 3|
|Masonry||—||—||1||—||11/2 - 3|
|Plastic||—||1||—||11/2 - 3|
For SI: 1 inch = 25.4 mm, 1 pound = 0.454 kg.
- Lime by volume of 0 to 3/4 shall be used where the plaster will be placed over low-absorption surfaces such as dense clay tile or brick.
- The same or greater sand proportion shall be used in the second coat than used in the first coat.
Each coat shall be kept in a moist condition for not less than 24 hours prior to application of the next coat.
Exception: Applications installed in accordance with ASTM C926.
Supports and fasteners used to attach gypsum board and gypsum panel products shall comply with Table R702.3.5. Gypsum sheathing shall be attached to exterior walls in accordance with Table R602.3(1). Gypsum board and gypsum panel products shall be applied at right angles or parallel to framing members. All edges and ends of gypsum board and gypsum panel products shall occur on the framing members, except those edges and ends that are perpendicular to the framing members. Interior gypsum board shall not be installed where it is directly exposed to the weather or to water.
GYPSUM BOARD OR
|MAXIMUM SPACING OF|
|SIZE OF NAILS FOR APPLICATION|
TO WOOD FRAMINGc
|Application without adhesive|
|3/8||Ceilingd||Perpendicular||16||7||12||13 gage, 11/4" long, 19/64" head; 0.098" diameter, 11/4" long, annular-ringed; or 4d cooler nail, 0.080" diameter, 13/8" long, 7/32" head.|
|1/2||Ceiling||Either direction||16||7||12||13 gage, 13/8" long, 19/64" head; 0.098" diameter, 11/4" long, annular-ringed; 5d cooler nail, 0.086" diameter, 15/8" long, 15/64" head; or gypsum board nail, 0.086" diameter, 1 5/8" long, 9/32" head.|
|5/8||Ceiling||Either direction||16||7||12||13 gage, 15/8" long, 19/64" head; 0.098" diameter, 13/8" long, annular-ringed; 6d cooler nail, 0.092" diameter, 17/8" long, 1/4" head; or gypsum board nail, 0.0915" diameter, 17/8" long, 19/64" head.|
|Type X at|
|Perpendicular||24||6||6||17/8" long 6d coated nails or equivalent drywall screws. Screws shall comply with Section R702.3.5.1|
|Wall||Either direction||24||8||12||13 gage, 15/8" long, 19/64" head; 0.098" diameter, 13/8" long, annular-ringed; 6d cooler nail, 0.092" diameter, 17/8" long, 1/4" head; or gypsum board nail, 0.0915" diameter, 17/8" long, 19/64" head.|
|Application with adhesive|
|3/8||Ceilingd||Perpendicular||16||16||16||Same as above for 3/8" gypsum board and gypsum panel products.|
|1/2 or 5/8||Ceiling||Either direction||16||16||16||Same as above for 1/2" and 5/8" gypsum board and gypsum panel products, respectively.|
|Ceiling||Perpendicular||16||16||16||Base ply nailed as above for 1/2" gypsum board and gypsum panel products; face ply installed with adhesive.|
For SI: 1 inch = 25.4 mm.
- For application without adhesive, a pair of nails spaced not less than 2 inches apart or more than 21/2 inches apart shall be permitted to be used with the pair of nails spaced 12 inches on center.
- Screws shall be in accordance with Section R702.3.5.1. Screws for attaching gypsum board or gypsum panel products to structural insulated panels shall penetrate the wood structural panel facing not less than 7/16 inch.
- Where cold-formed steel framing is used with a clinching design to receive nails by two edges of metal, the nails shall be not less than 5/8 inch longer than the gypsum board or gypsum panel product thickness and shall have ringed shanks. Where the cold-formed steel framing has a nailing groove formed to receive the nails, the nails shall have barbed shanks or be 5d, 131/2 gage, 15/8 inches long, 15/64-inch head for 1/2-inch gypsum board or gypsum panel product; and 6d, 13 gage, 17/8 inches long, 15/64-inch head for 5/8-inch gypsum board or gypsum panel product.
- Three-eighths-inch-thick single-ply gypsum board or gypsum panel product shall not be used on a ceiling where a water-based textured finish is to be applied, or where it will be required to support insulation above a ceiling. On ceiling applications to receive a water-based texture material, either hand or spray applied, the gypsum board or gypsum panel product shall be applied perpendicular to framing. Where applying a water-based texture material, the minimum gypsum board thickness shall be increased from 3/8 inch to 1/2 inch for 16-inch on center framing, and from 1/2 inch to 5/8 inch for 24-inch on center framing or 1/2-inch sag-resistant gypsum ceiling board shall be used.