Page 295 - Masonry and Concrete

Paving

294 CHAPTER EIGHT

sion on the short side of a full 4-ft. 8-ft. sheet of plywood. Draw a
straight line perpendicular to the long side of the plywood to equal
the depth of the landing. Allow a slight slope away from the building
1
of about 2% for drainage (approximately 4 in. per foot). If the land-
3
ing is 3 ft. wide, this would be a total slope of 4 in. from back to
front. For a 4-ft. landing, a total of 1 in. Measure down 1 in. and draw
a line between this mark and the height of the landing at the edge of
the plywood sheet (Figure 8-17). Next, use a carpenter’s square to
draw the outline of each riser and tread at the calculated height and
depth. Remember that there will be an extra 6 in. of plywood at the
bottom of the form that will be below grade. To create a slanted riser,
angle the riser face backward 1 in. as shown. This will produce a
“sawtooth”-shaped profile. To allow water to drain off the steps eas-
3
1
ily, each tread should also be sloped. Measure up 16 to 4 in. at the
back corner of each tread to get a 2% slope and draw a line to the front
edge (Figure 8-18). Cut the first plywood form, then use it to draw the
profile for the form for the other side. With lumber side forms, slanted
risers are created by using wood cleats at the sides to set the proper
angle and hold the riser boards in place (Figure 8-19).

4 FT. 8 FT. PLYWOOD

3'-0" MIN. LANDING TREAD DEPTH

SLOPE 1/4" PER FOOT (2%)

RISER HEIGHT

1"

6" BELOW GRADE

FIGURE 8-17
Making plywood forms for steps.

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