Q:
I framed the stairs in our new addition allowing for a vinyl floor. But my wife changed “our” mind (we want hardwood). The math changed, too—now the bottom step is 3/4 in. too short. Please tell me there’s an easy way to fix the problem without tearing out and replacing the stair stringers.
Zack Flagg, Northport, ME
A:
Bruce Abernathy, a finish carpenter specializing in stairs in Niceville, Florida, replies: This problem is fairly common. Sometimes customers change their minds, or sometimes a framer forgets to account for the flooring thickness. You can make up the difference with scrap plywood and still be well within the International Residential Code’s allowance of up to 3/8-in. variation in stair risers.
You allowed for very little finished-flooring thickness, and your wife changed it to 3/4 in. As a result, the bottom step is 3/4 in. too short. Cut a piece of 3/4-in. plywood to fit the tread of the bottom step, and glue and screw it down. If large pieces of plywood are scarce, use small pieces to pad the framing.
On the second step, install a piece of 5/8-in. plywood. On the third, use 1/2 in., then 3/8 in., 1/4 in., and finally a thin layer of lauan or even a few shims. Each riser will vary by 1/8 in., but it won’t be noticeable walking up or down the stairs; it’s also safe and legal. Best of all, you won’t need to replace the rough frame. Incidentally, this same trick works from the top if the flooring change happens there.
