16–1 DRYWALL AND
WETWALL CONSTRUCTION
Although drywall construction utilizes wallboards and wet-
wall utilizes plaster and stucco, many components of the two
systems of construction are interchangeable. Both require
that supporting construction be applied under them, and
the same types are used for both. Many of the fasteners,
attachments, and accessories are the same or very similar.
All supporting systems and furring should be installed
in accordance with the specifications, and the manufac-
turer’s recommendations for spacing, accessories, and instal-
lation should be consulted. If the specifications by the
architect/engineer are stricter than the manufacturer’s, it is
those specifications that must be followed. If the project
specifications are less stringent than those of the manufac-
turer, it is advisable to call the architect/engineer’s office to
be certain what must be bid. Many manufacturers will not
guarantee the performance of their materials on the job
unless those materials are installed in accordance with their
recommendations.
16–2 SUPPORTING
CONSTRUCTION
The wallboard can be applied directly to wood, metal, con-
crete, or masonry that is capable of supporting the design
loads and provides a firm, level, plumb, and true base.
Wood and metal supporting construction often consists
of self-supporting framing members, including wall studs,
ceiling joists, and roof trusses. Wood and metal furring
members such as wood strips and metal channels are used
over the supporting construction to plumb and align the
framing, concrete, or masonry.
Concrete and Masonry. Concrete and masonry often
have wallboard applied to them. When used, either exterior
and below grade, furring should be applied over the concrete
or masonry to protect the wallboard from damage due to
moisture in the wall; this is not required for interior walls.
Furring may also be required to plumb and align the walls.
The actual thickness of the wall should be checked so
that the mechanical and electrical equipment will fit within
the wall thickness allowed. Any recessed items such as fire
extinguishers and medicine cabinets should be carefully
considered.Wood Studs. The most common sizes used are 2 4 and
2 3, but larger sizes may be required on any particular pro-
ject: Spacing may vary from 12 to 24 inches on center, again
depending on job requirements. Openings must be framed
around, and backup members should be provided at all cor-
ners. The most common method of attachment of the wall-
board to the wood studs is by nailing, but screws and
adhesives are also used. Many estimators take off the wood
studs under rough carpentry, particularly if they are load
bearing. The number of board feet required can be deter-
mined from Figure 13.1, using the length of partition, in
conjunction with Figure 13.7, which takes into consideration
the various spacings. Special care should be taken with stag-
gered and double walls so that the proper amount of mater-
ial is estimated.Wood Joists. The joists themselves are estimated under
rough carpentry (Chapter 13). When the plans require the
wallboard to be applied directly to the joists, the bottom
faces of the joists should be aligned in a level plane. Joists
with a slight crown should be installed with the crown up,
and if slightly crooked or bowed joists are used, it may be
necessary to straighten and level the surface with the use of
nailing stringers or furring strips. The wallboard may be
applied by nailing or by screwing.Wood Trusses. When used for the direct application of
wallboard, trusses sometimes require cross-furring to pro-
vide a level surface for attachment. Stringers attached atFINISHES
CHAPTER SIXTEEN
196