may be made of hollow metal, sheet metal, composite
wood with incombustible cores, and other composite con-
structions. Special hardware will be required, and the
frame may also have to be labeled.
Fire-rated doors may be conventionally operated, oper-
ated by the fire alarm system, or be horizontal or vertical
slide doors that close when the fusible link releases.
Acoustical Doors. Acoustical doorsare doors specially
designed and constructed for use in all situations when
sound control is desired. The doors are generally metal or
wood, with a variety of cores used. Because the doors avail-
able offer a wide range of sound control, the estimator should
use caution in selecting the right door to meet the specifica-
tions. When high sound control is required, double doors
may be desirable. Acoustical doors alone will not solve the
problem of noise transmission around the door. An auto-
matic drop seal for the bottom of the door and adjustable
doorstops (or other types of sound control devices) are used
at the doorjamb and head where the door meets the frame to
reduce sound transmission. Often, the seals and devices are
sold separately from the door. In these cases, estimators
determine the linear footage of the seal needed and include
its cost and labor charges in the estimate.
Overhead Doors. Overhead doorsare available in all
sizes. They are most commonly made of wood and steel,
although aluminum and stainless steel are sometimes used.
Overhead doors are first designated by the type of operation
of the door: rolling, sectional, canopy, and others. The esti-
mator must determine the size of door, size of opening, type
and style of door, finishes required, door hanger type, instal-
lation details, and whether it is hand, electric, or chain oper-
ated. The overhead door is priced as a unit with all the
required hardware. Often, the supplier will act as a subcon-
tractor and install the doors.
Miscellaneous Doors. There are a wide variety of spe-
cialized doors available to fill a particular need. Among these
are rolling grilles, which roll horizontally or vertically to pro-
vide protection or control traffic. Other specialty doors are
revolving, dumbwaiter, rubber shock-absorbing doors,
cooler and freezer doors as well as blast- and bulletproof
doors. The estimating procedures are basically the same,
regardless of the type of door required.
Folding Doors and Partitions. Folding (accordion)
doors and partitionsoffer the advantage of increased flexi-
bility and more efficient use of the floor space in a build-
ing. They are available in fiberglass, vinyl, and wood, or in
combinations of these materials. They can be made to
form a radius and have concealed pockets and overhead
track; a variety of hardware is also available. Depending on
the type of construction, the maximum opening height
ranges from 8 to 21 feet and the width from 8 to 30 feet.
The doors may be of steel construction with a covering,
rigid fiberboard panels, laminated wood, or solid wood
192 CHAPTER FIFTEEN
panels. Specially constructed dividers are also available
with higher sound-control ratings. The exact type required
will be found in the specifications, as will the hardware
requirements. Both the specifications and drawings must
be checked for installation details and the opening sizes
required.15–4 PREFITTING AND
MACHINING (PREMACHINING)
DOORS
The doors may be machined at the factory to receive vari-
ous types of hardware. Factory machining can prepare the
door to receive cylindrical, tubular, mortise, unit, and rim
locks. Other hardware such as finger pulls, door closers,
flush catchers, and hinges (butts) are also provided for.
Bevels are put on the doors, and any special requirements
are handled.
Premachining is popular as it cuts job labor costs to a
minimum, but coordination is important because the
work is done at the factory from the hardware manufac-
turer’s templates. This means that approved shop draw-
ings, hardware and door schedules, and the hardware
manufacturer’s templates must be supplied to the door
manufacturer.
From the estimator’s point of view, premachining takes
an item that is difficult to estimate and simplifies it consid-
erably. Except where skilled door hangers are available,
premachined doors offer cost control with maximum
results. For this reason, they are being used more and more
frequently.
Residential doors are often prehung. A prehung, inte-
rior door includes the door, frame, and hinges (butts) as a
single unit. An exterior, prehung door includes the door,
frame, exterior (brick) mold, hinges, threshold, and
weather stripping. Prehung doors are often machined for
the lockset.15–5 Prefinishing Doors
Prefinishing of doors is the process of applying the desired
finish on the door at the factory instead of finishing the
work on the job. Doors that are premachined are often pre-
finished as well. Various coatings are available, including
varnishes, lacquer, vinyl, and polyester films (for wood
doors). Pigments and tints are sometimes added to achieve
the desired visual effect. Metal doors may be prefinished
with baked-on enamel or vinyl-clad finishes. Prefinishing
can save considerable job-finishing time and generally
yields a better result than job finishing. Doors that are pre-
finished should also be premachined so that they will not
have to be “worked on” on the job. The prefinished door
must be handled carefully and installed at the end of the job
so that the finish will not be damaged; it is often difficult to
repair a damaged finish. Care during handling and storage
is also requisite.