Page 68 - Masonry and Concrete

Concrete Construction Techniques
67
CONCRETE CONSTRUCTION TECHNIQUES

edger and jointing tool respectively to touch
up. Wherever tile or pavers will be used as a
flooring, leave the concrete with this float
finish so that it will provide a good bond
with the setting bed. Wherever carpet or
hardwood floors will be laid, a float finish
provides an adequate substrate without any
further finishing work. A float finish also
provides moderate slip-resistance for exte-
rior surfaces such as driveways, patios, and
sidewalks. For a nonslip finish on exterior
sidewalks, patios, steps, or driveways, pull
a damp broom across the floated concrete
surface perpendicular to the direction of
FIGURE 3-25A
traffic (Figure 3-31). For a fine texture, use a
Bull float (Photo Courtesy PCA).
soft bristled brush. For a coarser texture, use
a broom with stiffer bristles. You will get
best results if you buy a broom made espe-
cially for concrete finishing.
Where resilient tile or sheet flooring
will be applied, the concrete surface must
be very smooth so that imperfections will
not “telegraph” through the flooring.
Where the concrete will be left exposed in
garages, utility rooms, and other areas,
the surface must be smooth so that clean-
ing or waxing is easier. For a smooth,
dense surface, a trowel finish is applied
with a steel finishing trowel. Hold the
blade nearly flat against the surface.
Sweep it back and forth in wide arcs, FIGURE 3-25B
overlapping each pass by one half the
Darby. (Photo Courtesy PCA).
trowel blade length (Figure 3-32). This
basically trowels the surface twice in one
operation. For an even smoother finish, go back over the surface
again after you have finished the initial troweling. Go back over
edges and control joints in outdoor work with the edger and jointing
tool respectively to touch up after troweling.

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