I am working on a project to replace my stair treads. The current treads show an ugly gap between the end of the tread and the existing skirt board. The current skirt board was installed before the treads, so the treads butt up against the skirt board. The current stairs had carpet on them so the gap didn't matter.

I want to put new treads on these stairs which are finished wood so that there is no visible gap between the end of the stair tread and the wall or skirt board. Can I meet this goal by installing the skirt board over the installed stair treads?

Should the skirt board or the stairs be installed first? Is the skirt board supposed to cover the gap between the tread and the wall?

Stair part diagram


3 Answers 3


Skirt boards are one of the hardest things in my opinion to do. I can rip apart a bathroom and have it put back together in 2-3 days and it might take me the same amount of time to make a couple of long stair skirts. All of your stairs wont be the exact same measurements, walls are not perfectly flat... One of the things that I source out now for sure.

The short answer is it depends. If the staircase will be carpeted or if there is no overhang on the treads then the answer is tread first. Basically this is faster because your treads don't have to be perfect. Also your skirt doesn't have to be perfect.

If your stairs will be showing the treads or if there is an overhang I would suggest installing the skirt and then the treads. This will give you a cleaner look. Also good luck notching out the skirt to match all of the overhangs on the tread if you decided to do it last.

  • If I install the skirt first, then the treads, how do I make sure there is no visible gap between the treads and the skirt? I will not have carpet on the stairs.
    – Freiheit
    Oct 4, 2013 at 16:38
  • Well you basically cut your tread width to the point where you have to gently hammer them home (maybe 1/16 inch long). If there is any more gaps you can fill with wood putty.
    – DMoore
    Oct 4, 2013 at 16:43
  • @Freiheit painted stairs = caulk. Stained stairs = perhaps shoe moulding or small cove moulding.
    – DA01
    Oct 4, 2013 at 16:45

You have a few options:

If you have access underneath, the best option is to rout tapered slots into the skirtboard. Both the risers and the treads fit into these slots, and then wedges are used to hold them in. Stairs built like this look wonderful, but it's a lot of extra work. If you want to pursue this, it's typically done with a router and a template. Fine Homebuilding has some good articles on this; it's typically known as "housed stairs".

It is possible to get decent butt joints, though you will run the risk of seasonal movement opening up some small gaps. The best way to do this is to with a stair measuring tool, which lets you accurately measure the angle between the tread and the skirt board. I did this on a set of stairs that I built a few years back, and the results were acceptable.


I had my stairs professionally done but I watched the carpenter so I'll mentioned what I observed. For the inside skirt board he cut it and installed before installing risers and treads. This way the treads and risers hide any gaps. If done afterwards it seems like it would be nearly impossible to cut accurately (around the nosing etc). He installed the risers next, then treads, then post, headrail, stained it, then balustrade.

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