USG IMPERIAL Gypsum Base - Manual

I MPERIAL Brand Gypsum Base may be installed either perpendicular (preferred) or parallel to the framing. All ends
and edges should be placed over framing members except where edge joints are perpendicular to framing. Use
maximum practical lengths to minimize end joints. Install gypsum base first on ceilings and then on walls. Over
steel studs, arrange direction of installation so that the lead edge of the base is attached to the open side of the
stud flange first. Bring base panels into contact with each other, but do not force into place. Fit abutting ends and
edges neatly; stagger end joints; arrange joints on opposite sides of partition so they occur on different studs.
Begin driving fasteners in center of panel and work toward ends and edges, holding gypsum base in firm
contact with framing. Space fasteners as shown in table and not less than 3/8
Љ from edges and ends of panel.
Drive fastener heads flush with surface without breaking the face paper. If gypsum base appears to be loose
from framing, install additional fasteners. Float vertical and horizontal interior corners by placing fasteners
8
Љ out from the corner. Where framing is parallel with the corner, attach one panel to corner framing and float
the abutting panel. Cut and fit gypsum base neatly around pipes and other openings. Remove loose face paper
around cuts and use quick-setting plaster to close openings.
Maximum spacing Base and finish assembly Framing spacing (1)
1/2 Љ 12.7 mm one layer, 1-coat system 16 Љ 406.4 mm
one layer, 2-coat system 16 Љ or 24Љ (2) 406.4 mm or 609.6mm (2)
two layer, 1 & 2-coat system 24 Љ 609.6 mm
5/8 Љ 15.9 mm one layer, 1-coat system 16 Љ or 24Љ (2) 406.4 mm or 609.6mm (2)
one layer, 2-coat system 24 Љ (2) 609.6mm (2)
two layer, 1 & 2-coat system 24 Љ 609.6mm
(1) For perpendicular or parallel application to framing. Perpendicular is preferred for maximum strength; parallel application is not
recommended for ceilings.
(2) 24
Љ (609.6 mm) spacing requires joint treatment with S
HEETROCK ® Brand Joint Tape and S HEETROCK ® Brand Setting-Type Joint Compound
(D URABOND ® or E ASY S AND ™ ).
Control Joints Apply control joints, where required, over the face of the gypsum base. Cut to required lengths with fine-toothed
hack saw. Cut end joints square, align and butt together slightly gapped. Attach the control joint to gypsum base
temporarily with 9/16
Љ rosin-coated staples spaced 12Љ o.c. along each flange. Complete the installation of the
control joint with fasteners (nails or screws) driven through the control joint flange into the framing on each side
of the joint. The protective plastic tape over the open groove should be left in place until finishing is completed.
Metal Trim Fasten gypsum base in normal manner but omit fasteners at framing member where metal trim is to be
installed. Leave a space 3/8
Љ to 1/2Љ wide between edge of base and face of jamb or wall. This provides space
for hardware or door bucks and allows for expansion when trim is used for perimeter isolation. Slip trim over
edge of base with expanded mesh flange on face side. Fasten to base by nailing or stapling 12
Љ o.c.
Vinyl Trim Slip vinyl trim over gypsum base with long flange behind base. Install the base with the trim firmly abutting
the surface.
Corner Bead Apply to all external angles. Hold tightly against angle and fasten to base by nailing or stapling 12 Љ o.c. alter-
nately on both flanges along entire length.
Acoustical Seal edges of gypsum base around entire perimeter of partition. Also, seal air-tight all penetrations of the
Sealant gypsum base, particularly electrical boxes. In addition to sealing the perimeter of electrical boxes, coat the
back sides with a layer of acoustical sealant. Apply acoustical sealant under control joints and similar openings
between the gypsum base and abutting materials.
I
MPERIAL
®
Brand
Gypsum Base
Application Tips
F
IRECODE ® Core
F
IRECODE
® C Core
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