09250.pdf

112-006 09250-1

SECTION 09250 1

GYPSUM DRYWALL 2

A. GENERAL 4

RELATED WORK SPECIFIED ELSEWHERE 6

Insulation to seal around penetrations and abutments to adjacent Section 07200 8 surfaces at gypsum drywall portions of fire and sound partitions 9

QUALITY ASSURANCE 11

Where gypsum wallboard systems with fire-resistance ratings or smoke partitions are indicated or are required to 13 comply with governing regulations, provide materials and installations identical with applicable assemblies which 14 have been tested and rated by UL (Underwriters Laboratories, Inc.) or other industry recognized agency. 15 On faces of work exposed in occupied spaces, limit offsets between planes of board faces to 1/8-inch, and limit 17 variations from plumb and location (including warp and bow) not to exceed 1/4-inch in 8'-0". 18

DELIVERY, STORAGE AND HANDLING 20

Gypsum drywall shall not be delivered to the project site until immediately before application begins. All gypsum 22 drywall materials shall be delivered in original packages, containers or bundles bearing brand name and 23 identification nomenclature. 24 Gypsum drywall shall be stored inside under cover and stacked flat in a manner to keep material flat, dry, 26 protected from weather, direct sunlight, surface contamination, traffic or other construction damage. Other 27 materials and accessories shall remain in their original wrappings or containers, stored flat and protected from 28 damage or bending until ready for actual use. 29 Handle gypsum boards in a manner to prevent damage to edges, ends or surfaces. Damaged gypsum boards or 31 accessories shall not be incorporated within the work and shall be immediately removed from the site. 32

JOB CONDITIONS 34

Comply with requirements of referenced gypsum board application standards and recommendations of gypsum 36 board manufacturer, for environmental conditions before, during and after application of gypsum board. 37 When outside temperatures are below 55 deg. F, maintain continuous interior temperature in the range of 55 deg. 39 F to 70 deg. F for minimum period of 48 hours prior to, during, and following application of gypsum board and joint 40 and finishing treatment materials or bonding of adhesives. 41 Ventilate building spaces as required to remove water in excess of that required for drying of joint treatment 43 material immediately after its application. Avoid drafts during dry, hot weather to prevent too rapid drying. 44

B. PRODUCTS 46

METAL STUDS 48

25-gauge studs shall be used throughout for interior applications, except 20-gauge shall be used at the following 50 locations: 51

- All 3 5/8" interior studs that are over 12-feet total height. Such studs shall be braced laterally at a 52 maximum height of 15-feet as described hereinafter. 53 Slip runner track shall be 20-gauge galvanized steel channel track of a width to fit over metal stud tracks specified 55 above and with 3-inch minimum legs placed at the top of all walls abutting structural members above as indicated 56 on the Drawings. 57

112-006 09250-2

Galvanizing repair paint shall be one of the following or approved equal: 1 Tnemec zinc rich primer 2 Carboline 658 zinc filled epoxy primer 3 Ameron Amercoat 68HS 4 Devoe Coatings 303H 5

GYPSUM BOARD 7

All gypsum board shall conform to ASTM C36, shall be 5/8-inch thick (unless noted otherwise on the Drawings) 9 regular board with tapered edges, and shall be one of the following (or approved equal): 10

G-P Regular Board Georgia-Pacific 11 Gold Bond Regular Gypsum Wallboard National Gypsum 12 Sheetrock Regular Gypsum Panels United States Gypsum 13

ACCESSORIES AND MISCELLANEOUS MATERIALS 15

Casing beads shall be Type 801-A metal trim manufactured by U.S. Gypsum or equal for installation with the fine 17 mesh on the exposed face. 18 Corner beads shall be Type 800 corner beads manufactured by U.S. Gypsum or equal for installation with the fine 20 mesh on the exposed face. 21 Control joints shall be formed by installing two (2) casing beads back-to-back with 1/16-inch gap in between, or by 23 using a ¼” wide by 7/16” deep vee-shaped trim with fine mesh on the exposed face. 24 Grout for all interior door frames which occur in stud walls shall be Durabond Joint Compound manufactured by 26 United States Gypsum Company or equal. 27 Fastenings shall be as follows: 28

Studs to track 3/8-inch drywall, Type S, pan head screws 29 Track to masonry 1/4-inch φ hooked anchor bolts 30 Track to concrete floor Cartridge driven studs or concrete nails 31 Track to metal deck Self-tapping screws (toggle bolts when required to hang 32 heavy bulkheads in tension) 33

JOINT TREATMENT 35

Joint treatment shall be paper reinforcing tape and ready-mixed vinyl-type compound by the same manufacturer as 37 the wallboard, except use fiberglass tape at moisture-resistant GWB. 38

COMPRESSIBLE FILLER 40

Compressible filler for use at sound partitions, as indicated on the Drawings, to fill gaps between partitions and 42 other penetrations, gaps between roof deck and/or structure, to close gaps around pipes, ducts, flues and other 43 penetrations, and to fill gaps between gypsum board and other materials, shall be sound blanket material as 44 specified in Section 07200. 45

FASTENERS 47

Screws shall be 1-inch, Type S, drywall screws for securing gypsum board to metal studs. 49 Nails shall be annular ring nails, GWB 54, 1 3/8-inches long for 1/2-inch GWB, 1 1/2-inches long for 5/8-inch GWB, 51 conforming to ASTM C 514. 52 Adhesive shall be Mastic No. 11 manufactured by Dow Corning Corporation unless other adhesive is 54 recommended by the gypsum board manufacturer. 55

112-006 09250-3

C. EXECUTION 1

INSTALLATION OF METAL STUDS 3

1. Install steel framing to comply with ASTM C 754 and ASTM C 840. 5

2. Align track at floor, top of masonry walls, frames and overhead structure as indicated on the Drawings. 6

Secure base track at 24-inch centers and at ends with power-driven fasteners as specified above. Head 7 track shall be held within the down-turn legs of specially formed 20-gauge galvanized steel slip runner 8 track welded or secured to bottom side of structure above for lateral support with deflection allowance of 9 1/2-inch or as otherwise indicated on the Drawings. See information earlier in this Section for locations 10 where the slip runner track is required at top of walls. Bulkhead or other similar construction which is to 11 be hung under tension shall have head track secured to structure at 16-inch centers minimum. Butt weld 12 or splice track at joints. 13

3. Set studs at partition ends, corners, and intersections; at jambs of openings and at 16-inch centers in 14 between unless shown otherwise on the Drawings. Seat studs squarely into track and plumb or align. 15 Secure studs to track as required. Studs shall be doubled adjacent to all metal frame jambs whether 16 shown on the Drawings or not. 17

4. Where stud partitions exceed 15-feet in height, provide lateral bracing to the structure above so the 18 unbraced height of the partition does not exceed 15 feet. If the studs are of sufficient length to extend full 19 height without splicing, the studs shall be braced by attaching a horizontal runner channel to one face of 20 the studs and extending diagonal 3 5/8" metal stud knee braces from that channel to the structure. 21 Spacing of knee braces shall be a maximum of 8-feet on center. 22

5. If the partition is of such height that the studs must be spliced, do so by installing two horizontal runner 23 channels back-to-back (one for the top of the lower wall and one for the bottom of the upper wall). Fasten 24 the runner channels to each other and then install diagonal knee braces at 8-feet maximum centers as 25 described above. 26

6. Install horizontal stiffener channels through studs at cut-out locations at maximum 6'-0" centers in 27 partitions which do not have GWB installed in both faces. 28

7. Install knee braces for metal frames and for walls which terminate above the ceiling as required to provide 29 lateral support. 30

8. At special slip runner tracks at tops of walls where deflection of the roof structure is anticipated, do not 31 anchor GWB to slip runner track. 32

9. Track at floor shall be deep leg track. 33

GROUTING OF METAL FRAMES IN STUD WALLS 35

Grout all hollow metal frames which occur in stud walls by spot-grouting at the jamb anchor clips prior to inserting 37 the gypsum board into the frame. Grout tightly to assure solid anchorage of the frame. Do not fill metal frame 38 jambs full of grout. 39

INSTALLATION OF GYPSUM BOARD 41

Install and finish gypsum board to comply with ASTM C 840. 43 Apply gypsum board beginning with the top wall panel, butted against the deck. At walls with lip runner track, hold 45 drywall down 5/8” below deck/structure. Apply panels of maximum practical length with long dimension at right 46 angle to supports. Center vertical joints over supports and stagger them from those of adjacent panel rows. 47 Vertical joints on opposite sides of a partition shall occur on different studs. Boards shall be brought into contact 48 with each other, but shall not be forced into place. 49 End joints may occur not closer than 8 inches from either side of openings in walls. No joint shall align with edges 51 of openings, and joints above openings shall be centered over openings. 52 Hold bottom edge of gypsum board off the floor by ½”. 54 Fastening panels shall be held in firm contact with the support member while the screws are being driven. 56 Fastenings shall proceed from the central portion of the board toward ends and edges. Fastenings shall be driven 57 home with the heads slightly below the surface of the board. Care shall be taken to avoid breaking the paper face. 58

112-006 09250-4

Improperly driven fastenings shall be removed. Space screws at 15-inch centers and locate 3/8-inch to 1/2-inch 1 from edges of panels. 2 After installation, pound on walls and ceilings to detect loose fastenings and push on board adjacent to fasteners 4 to see if there is movement. If loose fasteners are detected, drive them tight. Whenever fastenings have 5 punctured paper, hold board tight against framing and install another fastener properly, approximately 1-1/2" from 6 fastener head which punctured paper, and remove the faulty fastener. When fastening wallboard to second side 7 of a partition, check the opposite side for fasteners loosened by pounding and drive them tight again. 8

INSTALLATION OF ACCESSORIES 10

Corner beads shall be applied at outside corners with fasteners at 3-inch centers maximum on each flange of bead 12 with fasteners staggered. 13 Casing beads shall be applied to all exposed edges and ends of gypsum wallboard, back to back at control joint 15 locations and wherever indicated on the Drawings, with fasteners at 6-inch centers. 16 Control joints shall be placed where shown on the Drawings in continuous lengths with back-to-back casing beads 18 spaced with uniform 1/16" gap between backs. 19

COMPRESSIBLE FILLER 21

Completely fill all voids and gaps in and around the gypsum board at fire and sound partitions. See description of 23 these locations earlier in this Section. Tightly fit filler into these spaces to resist long-term displacement. 24

JOINT AND CORNER TREATMENT 26

A uniformly thin layer of joint compound shall be applied over the joint approximately 4 inches wide. Tape shall be 28 centered over the joint and embedded into the compound, leaving sufficient joint compound under tape to provide 29 proper bond. Inside corner angles shall be reinforced with tape folded to conform to the angle and embedded into 30 the compound. 31

FINISHING 33

After compound is thoroughly dry, the tape shall be covered with a coat of joint compound or topping compound 35 spread over the tape approximately 3 inches on each side of the tape and feathered out at the edge. After 36 thoroughly dry, another coat of joint compound or topping compound shall be applied with a slight, uniform crown 37 over the joint. This coat shall be smooth and the edges feathered approximately 3 inches beyond the preceding 38 coat. 39 All inside corners shall be coated with at least one coat of joint compound or topping compound with the edges 41 feathered out. Flanges of wallboard corner bead shall be concealed by at least two coats of compound. The first 42 coat shall be joint compound, and the second coat may be joint compound or topping compound feathered out 43 approximately 9 inches on both sides of the exposed metal nose. 44 Allow each application of compound to joint and fastener heads to dry, then sand if necessary. Caution shall be 46 used to avoid roughing of wallboard paper. Where more than one compound coat is specified herein, allow 24 47 hours drying time between coats. 48 Provide the following levels of gypsum board finish per GA-214: 50

1. Level 1 for ceiling plenum areas and concealed areas, unless a higher level of finish is required for fire-51 resistant-rated assemblies and sound-rated assemblies. 52

2. Level 4 for exposed gypsum board surfaces. (No textured ceiling coatings will be allowed). 53