Finishing Basement Stairs

By | February 20, 2016

Depending on the design of your home, you may have stairs leading to your basement that are unsightly and hazardous. This may be a great place for you to invest in the value and utility of your home. For the purpose of this post, I will consider a rough framed stairway that I would like to finish with carpet and a wall-mounted handrail.

First, inspect the existing stairs  and notice what the wall construction looks like.  Be sure that you have completed the drywall. Locate the studs and mark their location on the wall so that you can mount handrail hardware. Look at the current tread material. In many cases, the rough tread material was meant to be temporary and was intended to be removed.

It is important to ensure that there is as little variation as possible between the final tread riser heights. This includes the initial rise from the finished floor. This really can’t be stressed enough and is the primary rule in calculating stair stringer cuts: every rise of every step has to be the same. If you find yourself rebuilding an entire stair, Weyerhaeuser SturdiStep® system is a great place to start.


You’ll usually encounter stringers that have been framed from 1  1/4  inch rim joists or 1  7/8 inch micro-lam beams. If you are down to bare stringers, lay out your skirt boards. Lay them on the stringers and use a framing square to mark your cuts. Remember to plan to meet your baseboard. Start the cuts with a circular saw and finish with a jigsaw. They will be visible, so take your time. Once your skirt boards are cut, measure and plan your cuts for the risers and treads. Note any spacing blocks running past the center stringer. These can be great spots for added glue and screws or nails. The better you fasten your treads and risers, the fewer squeaks you will have.

Rip your first stair riser material at exactly the height of the riser cut on the stair stringer. This is the vertical cut or perpendicular from the floor. Each subsequent riser height will be reduced by the thickness of your tread. Your tread material needs to overhang past the riser at least 1  1/4 inches. Many come in an 11  1/2 inch tread depth with nosing. Your tread widths will be exactly the width of the space. Measure each stair to ensure that every tread and riser fits. Leave yourself a little space so you can glue, set, and screw each piece. Continue working from the bottom of the stairway to the top. They should be fairly close because your skirt boards are only about 3/4 inch wide. Your skirt board will sit on top of the end cuts to leave you with a fine finished product.

Next, fasten your skirt boards and mount the handrail. Once it’s painted, you’re ready for carpet! Give us a call if you have any questions.  Thanks for visiting!