Page 217 - Masonry and Concrete

Footings, Foundation Walls, Basements, and Slabs
216 CHAPTER SIX

ing steel in slabs, but reinforcing may be
VERTICAL required by some engineered designs. In
REINFORCING
BARS thin slabs, steel cannot be set the recom-
mended 3 in. above the subgrade, so it
should be placed at the midpoint of the
slab thickness. If the basement is prop-
erly designed for good drainage of soil
moisture, the reinforcing should be pro-
tected well enough to prevent corrosion.
LAP 30 BAR
DIAMETER AND Drainage and waterproofing, insulation,
TIE WITH WIRE and vapor retarders are discussed later in
this chapter.

6.4 Slabs-on-Grade

In warm climates where the frost depth is
minimal, shallow concrete foundations
are often designed and poured monolithi-
3" MIN. cally with the floor slab. These are referred
to as slabs-on-grade or slabs-on-ground.
FOOTING DOWEL The Code still requires that the bottom of
the footing be set a minimum of 12 in.
below the adjacent grade, that its mini-
FIGURE 6-25 mum width is appropriate to the type of
Footing-to-foundation wall connections. soil (refer to the table in Figure 6-4), that
1
the slab be at least 3- 2 in. thick, and the
concrete at least 2,500 psi. Interior bearing
walls require an integral footing with the same required width at the
bottom as the perimeter footing, but usually with a reduced depth (Fig-
ure 6-28). For masonry veneers, a perimeter ledge allows the masonry
to sit below the level of the finish floor (Figure 6-29). All top soil and
vegetation must be removed from the area within the footings and
replaced with a compacted fill material that is free of vegetation and
foreign material.
There are no requirements for steel reinforcing, but sill plates
1
must be anchored to the foundation with 2-in-diameter bolts
spaced 6 ft. on center and not more than 12 in. from corners. The
bolts must extend at least 7 in. into the concrete and have a 90° bend

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