Estimating in Building Construction

Finishes 199

Just as with the wood studs, the number of openings, intersections,
and corners needs to be counted.

Total studs (3^5 ⁄ 8 – )

(3^5 ⁄ 8 – )

Add 5 percent for waste — order 331(3^5 ⁄ 8 –  12 ¿) studs

315 studs

 246  39  22  8

4 interior corners — Add 2 studs per corner — 8 studs

— 22 studs

11 interior intersections — Add 2 studs per intersection

13 openings — Add 3 studs per opening — 39 studs Track (3^5 ⁄ 8 – )

Since runner track comes in 20-foot pieces, the following would be

required (8 percent waste factor):

35 ⁄ 8 –

Order 3 pieces of 6– 20 ¿ runner track 

Order 36 pieces of  20 ¿ runner track

Track (6–) 20 ¿ 8 –  2  41 ¿ 4 –

 325 ¿ 4 –  2  650 ¿ 8 –

Top and bottom runner track

Add 5 percent for waste — order 18 (6– 12 ¿) studs

FIGURE 16.4.Typical Grid Systems.

16–3 SUSPENDED CEILING

SYSTEMS

When the plaster, wallboard, or tiles cannot be placed
directly on the supporting construction, the wallboard is
suspended below the structural system. This may be
required if the supporting construction is not properly
aligned and true, or if lower ceiling heights are required.
A large variety of systems are available for use in drywall
construction, but basically they can be divided into two classes
(Figure 16.4): exposed grid systems and concealed grid systems.
Within each group, many different shapes of pieces are used to
secure the plaster wallboard or tile, but basically the systems
consist of hangers, main tees (runners), cross tees (hangers),
and furring channels. No matter which type is used, accessories
such as wall moldings, splines, and angles must be considered.
For wetwall construction, a lath of some type is required.
The suspension system and wallboard may also be used
to provide recessed lighting, acoustical control (by varying
the type of wallboard and panel), fire ratings, and air distri-
bution (special tile and suspension system).
The suspension system itself is available in steel with an
electro-zinc coating as well as prepainted and aluminum,
and with plain, anodized, or baked enamel finishes. Special
shapes, for example, steel shaped like a wood beam that is
left exposed in the room, are also available.
The suspension system may be hung from the support-
ing construction with 9- or 10-gauge hanger wire spaced
about 48 inches on center, or it may be attached by the use of
furring strips and clips.
From the specifications and drawings, the type of
system can be determined. The pieces required must be

listed, and a complete breakdown of the number of linear

feet of each piece is required. Estimators should check the

drawings for a reflected ceiling plan that will show the lay-

out for the rooms, as this will save considerable time in the

estimate. They should also take note of the size of the tile

to be used and how the entire system will be attached to

the supporting construction. Later, this information

should be broken down into the average amount of mate-

rial required per square to serve as a reference for future

estimates.

16–4 Types of Assemblies

Basically, drywall construction may be divided into two

basic types of construction: single-ply and multi-ply.

Single-ply constructionconsists of a single layer of wall-

board on each side of the construction, whereas multi-ply

constructionuses two or more layers of wallboard (and

often, different types of board) in the various layers

(Figure 16.5). The multi-ply construction may be semi-

solid or solid, or may have various combinations of mate-

rials. Estimators analyze what is required carefully so that

the takeoff and pricing may be as complete and accurate as

possible.

Various types of demountable and reusable assemblies

are also available. Estimators must take time to analyze the

assembly specified, break it down into each piece required,

and study its pieces and how they are assembled; then an

estimate can be made. As questions arise about an unfamil-

iar assembly, they should not hesitate to call the supplier or

manufacturer for clarification.