WORK PLANS - Laserfiche WebLink

Home Browse Search

GYPSUM WALLBOARD Section 09250 15-1207 finished with long tapered finish, smooth and even in texture. Surfaces shall be prepared to receive paint finish. 3.04 INSTALLATION A. Fire -resistive ratings: Where fire rated construction is indicated, install wallboard assembly to provide the fire -resistive rating required. B. Sheet arrangement layout: Conform to layouts and requirements indicated; use long sheets to restrict joints to minimum. Conditions met and not covered by plans and specifications shall be resolved in conformity with best practice of trade. C. Joints: Butt sheets loosely together with tapered edges always placed together (butt edges placed next to tapered edges are not permitted). Sand or kerf cut edges and mill ends to provide smooth jointing on exposed face. Stagger end joints. Shim wallboard on wood framing to get even joints without offsets. D. Fasteners: Place fasteners no less than 3/8 inch from edges of boards. Install fasteners with heads dimpled slightly below surface; do not cut through paper. Use crown face hammers for driving nails and approved power tools for self drilling screws. Fasten gypsum wallboard to all bearings as follows: 1. Ceilings, Non -rated: Screws 12 inches o.c. 2. Walls, Non -rated: Screws 12 inches o.c. 3. Ceilings, One-hour Rated: Base layer, screws 12 inches o.c.; Face layer, screws 8 inches o.c. 4. Walls, One-hour Rated: Screws 8 inches o.c. at edge bearings, 12 inches o.c. at field bearings. E. Ceilings: Place boards with long dimension at right angles to supports and end joint occurring over supports. On fire rated ceilings butted end joints may be placed between supports and reinforced on upper side with 8 inch wide wallboard back up strips set in approved adhesive. Place perimeters of ceilings and edges of openings over solid bearing members. F. Partitions: Place boards with long dimensions either vertical or horizontal (but not combination of both) on studs. Stagger vertical joints on opposite sides of partitions. Locate joints at least 12 inches from jambs of openings. Keep end joints to minimum. G. Cutting and scribing: Cut neatly to fit around outlets, switch boxes and other protrusions, using keyhole saw or specially designed cutting tool for opening of exact shape and size needed. H. Trim: Edge exterior corners with specified bead set to true plumb line. Where wallboard joins or abuts any material other than wall board, cover end of board with specified metal casing, leaving joint sufficient for installation of sealant. Attach trim with nails at wood studs at 9 inch O.C. each flange and type S-12 screws at steel studs at 9 inch O.C. each flange. No clenching allowed. Interior Wall Sealant: At all interior partitions, use double bead of specified material. Install at floors, wall intersections, where walls abut other materials and at all electrical boxes. Apply in accord with manufacturer's printed directions. 9