STAIRS ARE something most of us just take for granted, but if you think about it, they're anything but simple.
They are an important part of any multistory structure and often quite elaborate.
Almost all civilizations have created some kinds of steps; some ancient cultures built huge structures with stairs rising hundreds of feet. Baltimore is famous for its marble steps, most of which came from local quarries, such as those near Oregon Ridge. At the time, the white marble from these quarries was inexpensive -- which explains why so much of it was used for steps and window sills. (That's not so today, as anyone who has had to replace some would find out.)
These days, stairs are often a status symbol, creating a grand entrance with a huge sweep, incorporating everything from curves to exotic hardwoods to intricately detailed balustrade systems.
If you want to build or repair a set of stairs, it's important to know how to talk about the various parts, and to understand how they go together. The diagram below shows the basic parts, which should be enough information to describe to someone else what you want.
If you are trying to match or replace parts for an old stairway, you will have three choices. You can go to salvage yards and search -- you may get lucky and come across what you need. You can also look for new parts that resemble the old ones -- so closely they may not be noticeable. This is easier than it used to be, as more molding companies are reproducing old-fashioned stock.
However, if your stair parts are especially elaborate, or you want something not readily available, you can have the parts fabricated by a mill. A good mill should be able to duplicate any part you need, though it may be expensive. There typically will be a one-time charge for creating a jig, or pattern, plus a charge for each piece turned out. You will need to supply a sample if you want something duplicated exactly.
With new stairs you have more options. It is rare today to have stairs built completely from scratch, with the exception of those for porches and decks. Interior stairs are usually prefabricated and set in place as a unit. Even the banisters are often built as sections, so the installer has only to cut and fit the railings to the newel posts. You can even buy railings that will adjust to the slope you need as a unit.
An important thing to understand, if you are going to build even a simple a set of steps, is how to calculate the rise (height of each step) and run (length of each step). This example is for interior stairs:
Start with the distance the stairs have to bridge from finished floor to finished floor. For an 8-foot ceiling, this typically is about 106 inches. (Always work in inches.) Then divide the height by the number of risers to reach the next floor (for this 106-inch example, 14); 106 divided by 14 is 7 1/2 inches for each step. Most building codes specify limits for the rise -- that's because if they're too low, people might trip, and if they're too high, it's like climbing a ladder. Somewhere between seven and eight inches is the safest and most comfortable distance. If your rise is outside those limits, you need to add or subtract another step so it will conform.
Now you can calculate the run of the stairs; this is typically 10 inches (and it doesn't include the overhang of the nosing, or rounded front edge of the tread). There is always one less tread than there are risers, since the last step at the top is the next floor. So multiply 10 times 13 to determine the total length. If there are landings involved, treat them as another riser and add its width to the overall length. For a straight of 14 risers, the run distance is 130 inches. That's how much floor space the stairs take up.
If you're building stairs, you also have to think about vertical clearance; there needs to be at least six feet eight inches of height from the nose of the tread to the ceiling. The vertical clearance can be much higher -- as in those two-story grand staircases -- but it cannot be lower at any point.
Obviously, building stairs can be a complicated process -- even a dangerous one if they're not built correctly -- so unless you know what you're doing, it's better to hire a professional.
If you have questions, tips or experiences to share about working on houses, e-mail Ron at henovator.net or Karol at karol.menzialtsun.com. Or write c/o HOME WORK, The Sun, N. Calvert St., Baltimore, Md. 21278.
Pub Date: 10/04/98