Q: I am in a similar situation as Tim from May 2007 and I am about to redo stairs that were previously carpeted. As with Tim I tore out the old carpeting and plan to do the treads with flooring, not planks. My question is: Do I need to have an expansion gap in the tread that will be hidden underneath the new riser? I assume not since there will be only two and a half boards between the nosing and the riser, which is not enough wood to create a noticeable amount of expansion. I was thinking about leaving a 1/8″ gap, but I don’t want to compromise the strength of the riser that rests on it.
Thanks,
Jerrod
A: You will need to leave an expansion gap and keep in mind that there is a small gap between the riser and the tread. Also remember that the riser is directly adhered to the stairs frame, so its not much of a matter of stability in regards to leaving a gap. Wood being a natural product will expand and contract due to temperature and moisture, so you must account for a gap based on the amount and type of flooring to be installed.
The gap for stairs does not need to be as large as typically used for flooring and 1/8″ should do. Also keep in mind you can leave some room on the side for expansion if you are going to be covering it with a Skirt board.
