USG DIAMOND Veneer Basecoat Plaster - Manual

Preparation Protect the product from moisture during storage and on the job. In cold weather, heat the interior of the building to
a minimum of 55 °F (13 °C) for an adequate period before the application of plaster, while basecoat and finish is
being applied, and until the finish is dry. Air circulation should be kept at a minimum level during application and
until proper set has been achieved.
Application Joint Treatment Glass Fiber Tape Apply I MPERIAL ® Brand Tape over all joints (edges and ends) Do not overlap tape at intersections.
Align pressure-sensitive Type P Tape over joints and press in place over the tape’s entire length. Then, to eliminate
wrinkles and assure maximum adhesive bond, press the entire length of the tape with a steel finishing knife or
trowel; press the tape into corners with a corner tool.
Attach Type S Tape with a spring-driven hand stapler using 3/8
Љ (9.5 mm) staples. Use two staples at each
end of the tape; staple the remainder at staggered 24
Љ intervals. At wall-ceiling angles, staple tape every 18Љ to
24 Љ along the ceiling edge only; for wall and partition interior angles, staple every 18Љ to 24Љ on one edge only,
working from top to bottom. Position the tape to bridge the joint at all interior corners. For fire-rated assemblies,
staple either Type P or Type S Tape 8
Љ o.c.
S HEETROCK ® Brand Joint Treatment System S HEETROCK ® Brand Joint Tape and S HEETROCK ® Brand D URABOND ® Setting-
Type or E ASY S AND ™ Lightweight Setting-Type Joint Compound must be used to treat all joints and internal
angles when any of the following conditions exist: Building temperature/humidity conditions fall in the “rapid
drying” area of the graph below; metal framing is specified; 24
Љ o.c. wood-frame spacing and a single-layer
gypsum base veneer system is specified (5/8 Љ base with one-coat veneer finish and 1/2Љ or 5/8Љ base with
two-coat veneer finish). Allow joint treatment to set and dry thoroughly before plaster application.
Mix the joint compound in a clean 5-gal. container (plastic is preferred). Use a commercial potato masher or
a 1/2
Љ heavy duty 200- to 300-rpm electric drill with a drywall blade-type mixing paddle. Drill speed must
not exceed 400 rpm. Use the amount of water shown on the bag and always sift the powder into the water to
ensure complete wetting. Stir vigorously for 3 minutes; if lumps remain, allow the mix to soak for a minute or
two then restir until smooth.
Note: Do not contaminate compound with other materials, dirty water or previously
mixed batches. Do not retemper batches.
Butter the joints with compound using a trowel or steel finishing knife to force the compound into the joints.
Center S
HEETROCK Brand Joint Tape and press it into the fresh compound with the trowel held at a 45° angle.
Draw the trowel along the joint with sufficient pressure to remove excess compound. After the tape is embedded,
apply a skim coat of joint compound to reduce possibility of edge wrinkling or curling. Allow skim coat to set.
Mix and apply a finish coat so that it completely covers the tape and feather it 3 Љ to 4Љ beyond edges of the
tape. Allow it to set and dry before plastering. Plaster prefill is not required over setting-type joint compound.
D
IAMOND
®
Brand
Veneer Basecoat Plaster
Application Tips
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