Estimating in Building Construction

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108 CHAPTER TEN


10–5 Accessories


Any item cast into the concrete should be included in the con-
crete takeoff. The list of items that might be included is exten-
sive; the materials vary depending on the item and intended
usage. The accessory items may include the following:


Expansion Joint Covers. Made of aluminum and
bronze, expansion joint covers are available in a wide variety
of shapes for various uses. Takeoff by the linear footage is
required.


Expansion Joint Fillers. Materials commonly used as
fillers are asphalt, fiber, sponge rubber, cork, and asphalt-
impregnated fiber. These are available in thicknesses of 1/4,
3/8, 1/2, 3/4, and 1 inch; widths of 2 to 8 inches are most com-
mon. Sheets of filler are available and may be cut to the desired
width on the job. Whenever possible, filler of the width to be
used should be ordered to save labor costs and reduce waste.
Lengths of filler strips may be up to 10 feet, and the filler
should be taken off by linear feet plus 5 percent waste.


Waterstops. Used to seal construction and expansion
joints in poured concrete structures against leakage caused
by hydrostatic pressure, waterstops are commonly composed
of polyvinyl chloride, rubber, and neoprene in a variety of
widths and shapes. The takeoff should be in linear feet, and
the estimator must check the roll size in which the specified
waterstop is available and add 5 percent for waste. Full rolls
only may be purchased (usually 50 feet long).


Manhole Frames and Covers. Manhole frames and
covers are available in round or square shapes. The frame is
cast in the concrete, and the cover is put in the frame later.
The materials used are aluminum (lighter duty) and cast
iron (light and heavy duty). The covers may be recessed to
receive tile; have a surface that is plain or abrasive; or have
holes put in them, depending on the intended usage and
desired appearance. The size, material, type, and installation
appear in the specifications and on the drawings. They are
taken off by the actual number of each type required. The
various size frames and types of covers cost varying
amounts, so different items are kept separate.


Trench Frames and Covers. The trench frame is cast in
the concrete. The linear footage of frames required must be
determined, and the number of inside and outside corners
must be noted as well as the frame type. Cast-iron frames are
available in 3-foot lengths, and aluminum frames are avail-
able up to 20 feet long. Covers may also be cast iron or alu-
minum in a variety of finishes (perforated, abrasive, plain,
recessed).
The takeoff is made in linear feet with the widths, mate-
rial, and finish all noted. Cast-iron covers are most com-
monly available in 2-foot lengths, while aluminum frames
are available in 10-, 12-, and 20-foot lengths, depending on
the finish required. Many cast-iron trench manufacturers


will supply fractional sizes of covers and frames to fit what-
ever size trench length is required. Unless the aluminum
frames and covers can be purchased in such a manner, siz-
able waste may be incurred on small jobs.
Miscellaneous accessories such as anchor bolts, bar
supports, screed chairs, screw anchors, screw anchor bolts,
plugs, inserts of all types (to receive screws and bolts),
anchors, and splices for reinforcing bars must be included
in the takeoff. These accessories are taken off by the num-
ber required; they may be priced individually or in 10s, 25s,
50s, or 100s, depending on the type and manufacturer. The
estimator must carefully note the size required since so
many sizes are available. The material (usually steel, cast
iron, or plastic) should be listed on the drawings or in the
specifications. Some inserts are also available in bronze and
stainless steel.
Accessories such as reglets, dovetail anchor slots, and
slotted inserts are taken off by the linear footage required.
Available in various widths, thicknesses, and lengths, they
may be made out of cold rolled steel, galvanized or zinc-
coated steel, bronze, stainless steel, copper, or aluminum.

Estimate Expansion Joint Filler. Determine from the
plans, details, and sections exactly how many linear feet are
required. A 1/2-inch-thick expansion joint filler is required
where any concrete slab abuts a vertical surface. This would
mean that filler would be required around the outside of the
slab, between it and the wall.

10–6 Concrete Finishing


All exposed concrete surfaces require some type of finishing.
Basically, finishing consists of the patch-up work after the
removal of forms and the dressing up of the surface by trow-
eling, sandblasting, and other methods.
Patch-up work may include patching voids and stone
pockets, removing fins, and patching chips. Except for some
floor slabs (on grade), there is always a certain amount of
this type of work on exposed surfaces. It varies considerably
from job to job and can be kept to a minimum with good-
quality concrete, with the use of forms that are tight and in
good repair, and with careful workmanship, especially in
stripping the forms. This may be included with the form-
stripping costs, or it may be a separate item. As a separate
item, it is much easier to get cost figures and keep a cost con-
trol on the particular item rather than “bury” it with strip-
ping costs. Small patches are usually made with a
cement-sand grout mix of 1:2; be certain that the type of
cement (even the brand name) is the same used in the pour,
because different cements are varying shades of gray. The
labor hours required will depend on the type of surface, the
number of blemishes, and the quality of the patch job
required. Scaffolding will be required for work above 6 feet.
The finishes required on the concrete surfaces will vary
throughout the project. The finishes are included in the
specifications and finish schedules; sections and details
should also be checked. Finishes commonly required for
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