I taught night school at a community college for 20 or so years. My students were apprentice carpenters learning how to build houses. Often, students were hesitant to take on the task of building stairs because of the presumed difficulty. It came as a surprise to most of them that building stairs—especially a simple, straight flight of stairs—is actually quite easy. If you can do some basic math and know how to use
Because we are using 11/2-in.thick treads, 11/2 in. has to be cut from only the first riser to make each rise equal after thetreads are screwed in place.
a framing square and a circular saw, you can build stairs. Although stair-building principles are the same everywhere, different states (and towns or cities) sometimes use different codes, so check to see which code requirements apply in your area.
The accepted standards for a typical stairway call for a rise of about 7 in. and a run, or tread width, of 11 in. When calculating the number of risers in a stairway, aim to stay as close as possible to those figures. If you have a pocket calculator handy (see Resources on p. 279), this calculation is easy to do.
First, determine exactly how high each riser will be. This is calculated based on the total rise, which is measured from finish floor to finish floor—in this case, from the concrete slab to the top of the porch decking. Let’s call it 30 in., a fairly typical porch height. Divide the total rise (30 in.) by 7 in., the standard riser height, for a total of 4.3 risers. Round that to the closest whole number (in this case, 4) and divide your total rise of 30 in. by that number. This gives you an individual riser height of 7.5, or 71/2 in. Now you have the riser height and the number of risers—4 risers, each 71/2 in. high.
You can also determine the total run of the stairs; this will tell you where the concrete landing or base for the stringers should be. Do a rough sketch of the stairs, then multiply the number of treads by the tread width (in this case, 11 in.). Keep in mind that you can either run the stringers flush with the top of the deck (the top tread is even with the deck surface) or cut the stringers so that the top tread is one step down from the deck surface. The latter approach is more common; that’s what we did on the house shown here.
