Maximizing stair width for basement stairs

[branimal]

I'm building a new set of stairs for my basement. I'd like to maximize width. In order to do that I'm going to leave the foundation wall exposed in the staircase area. I'm also going to leave the staircase header exposed.

Any tips or insight appreciated.

Here's a mockup of my best idea so far....

1. Blockout left stringer. Attach skirtboard to blocking
2. Cap skirtboard with 1x2 or 1x3, scribe to the foundation wall. I think this is going to be a long shot to get right. I could bevel the edge of the cap piece giving me a sharp point to scribe to the foundation wall.

I still need to think thru how I'm going to skirt around that pipe.

** foundation wall is shared with neighbors rowhouse. I mention this b/c its not taking on water/moisture from outside.

 

[Superbowl]

What pipe?

Are you going to finish the basement?

 

[The Cobbler]

I had a similar situation at a family members rental I renovated.
I did non housed stringer at the wall, and housed stringer at the wall side. Just scribe the treads to the foundation wall and cut them to length to fit in the dado on the housed stringer .
don't worry about the pipe.
part of renovations is making the best of a situation, not always perfection

 

[branimal]

What pipe?

Are you going to finish the basement?

The pipe is near the bottom of the stringer. Just under that scrap piece of skirtboard. Yes basement will be completely refinished. Drywall, lvp on the floor. Open space with a powder room. Which is just under the staircase. See toilet pipe.

I had a similar situation at a family members rental I renovated.
I did non housed stringer at the wall, and housed stringer at the wall side. Just scribe the treads to the foundation wall and cut them to length to fit in the dado on the housed stringer .
don't worry about the pipe.
part of renovations is making the best of a situation, not always perfection

Are you saying to scribe the treads to the foundation wall and skip the skirt board on that side altogether? Interesting. Maybe i'll do a test run. I would have to scribe the risers as well.

 

[branimal]

This guy scribed to a stone wall..... Awesome work. I've scribed to flooring and moulding to brick in the past. It's a long, tedious process.

Amero Woodworks on Instagram: "Worth it or nah? . . This was previously the foundation and underground. Now the basement stairs run along this foundation wall. I was sort of questioning everyone’s decision to do this but this flight was one that I

278 likes, 37 comments - amerowoodworks on November 3, 2025: "Worth it or nah? . . This was previously the foundation and underground. Now the basement stairs run along this foundation wall. I was sort of questioning everyone’s decision to do this but this flight was one that I had the most...

www.instagram.com

 

[mm08822]

I think your first idea of a skirt board is the fastest. All cuts for stringers, treads, risers remain straight cuts.

Even if you botch the skirt board scribing, it could be pieced together and still look good.
Real easy to botch a custom field fit towards the end.
Any stringer should be full width lumber and not reduced with scribing. You would need to double up the wall side stringer if you were to scribe it. This leaves one completely uncompromised.

While I'm thinking about it, doubling up the stringers on both sides would help reduce the deflection as people run up/down the steps.

 

[Stuart in MN]

I like the idea of skipping a skirt board, although scribing the steps to that wall will be tedious, it looks pretty lumpy. On the side facing into the room you could make the treads a little wider and that will help, although of course the limiting factor is the size of the opening in the floor above.

 

[rlitman]

Widest option would be to build a wall under the header and end the staircase one step from the top, as wide as you want, because you're no longer limited by the doorway. Of course that make the handrail on that side weird, but you could have a narrow staircase that chokes down around the top step (and that joist). If that supporting wall doesn't hurt the layout in the basement too much you could make it feel a LITTLE wider (maybe 2-3").

I too would recommend a third stringer. Any chance these stairs will see a handtruck carrying down appliances or a boiler?

As for skirt board or not, you feel the width of the staircase at your shoulders, not at your feet. It makes the treads wider, but by not making the wall to wall spacing wider, it doesn't widen the stairs.

 

[Stuart in MN]

Yeah, another stringer down the middle is a good idea. More capacity for moving heavy objects, and it will feel stiffer in day to day use.

 

[CraigStu]

Does finishing the basement include covering the stone wall. If so the skirt could somehow provide something to attach the wall covering to I guess. If it were mine I'd figure a clear coat on the stone to make it look a little nicer and reduce dust. I'd skip the skirt board and run both stair tread and riser to the stone. I'd do somewhat of a scribe and trim but wouldn't go anywhere near as nice as the one you linked. I guess it depends on how finished you want to finish it.

 

[carlaisle]

This may not work since that's a shared wall, but I have used an angle grinder with a diamond blade to grind a nice flat dado in a rough stone wall. Provided support for the stringer and eliminated all of the individual scribing.