Basement Stair Building Basics

Stringers

• The key piece of framing for a typical basement stairway is lumber that has been cut to allow for the placement of treads. Called stringers, these pieces of lumber span the length of the staircase and are positioned on either side of the stairwell. You can also use more than two stringers to give the stairway added support. Lumber used for stringers, usually 2-by-12s, may have 2-by-4s placed underneath to strengthen the framework.

Treads

• The section of the stairway where you place your foot, called the tread, is usually 10 inches deep while the riser, the board between the treads, is about 7 inches high. Each tread in the stairway must have an equal depth and each riser an equal height. The treads should overhang the risers by about 1 inch. Using both wood glue and screws to fasten the treads and risers provide a secure connection and prevent squeaks.

Landing

• A basement stairwell needs a landing for safety purposes. The basement door, when opened, should not extend to the first step. The landing length should equal the staircase's width, but should remain under 4 feet provided that the stairway has a straight run with no changes in direction. You need a landing in the middle of basement stairways that rise more than 12 feet.

Exterior

• Another type of basement stairway, an exterior stairway that leads to the inside, requires cutting an opening in the foundation's walls to accommodate the stairs. The staircase may be made from wood framing or precast concrete. The contractor builds an areaway or cutout in the foundation that allows for the placement of the stairway and the above-ground entrance doors. The metal doors sit on the foundation walls and must be fitted precisely to prevent leaks.