I am in the process of converting our housed stringer stairs to an open stringer format and have some questions about placement of the stringers. We have an L-shaped stairway going from the first floor to the second floor (see attached) and a straight stair way going from the first floor to the basement (see attached). First floor to second floor

First floor to basement

I feel comfortable removing the housed stringers and replacing them with sawtooth stringers to open it up. However, the problem I discovered is the ceiling in the stairway leading to the basement is directly screwed to the housed stringer of the stairway leading to the second floor (see attached).
cutaway of ceiling In other words, if i replace that housed stringer with a sawtooth stringer, the ceiling in the basement stairway will have to be lowered considerably.

I could move the wall in an inch on each side of the stairway going to the basement to hide the stringer, but that seems like a lot of extra work for minimal gain.

Any ideas on how I can do this without moving the wall and ceiling in the basement stairway (also, i realize that the ceiling will have to come down in the basement stairway during the project, thats no problem)? The goal is to keep the basement stairway as wide and tall as possible while still keeping the drywall there.

Thanks a lot in advance!

  • 1
    I don't think I understand the nature of your project. You already have "sawtooth" stringers. You can see that the tread and riser boards pass by the stringer and don't rest on cleats. (They wouldn't be mortised into the stringers with rough framing, and you'll find a third stringer in the center that wouldn't exist with housed stairs.) Do we have terminology confusion, or have you misinterpreted the nature of your existing framing?
    – isherwood
    Feb 14, 2018 at 19:47
  • I may have some terminology confusion... however, there are only 2 stringers (2x10s) that are notched to receive the 2x treads. They are glued into the notch.
    – M. Markson
    Feb 14, 2018 at 20:21
  • So if you put your arm in that hole you can reach the far stringer on the left? There may be only two stringers, but how are they not "sawtooth"?
    – isherwood
    Feb 14, 2018 at 20:34
  • 1
    I have not seen housed stringers that look like that. That looks to me a 2X12 cut to set the treads on top, spaced off the wall by another 2X4 from the side wall framing so that when the drywall goes on there is still enough room to add skirt boards without all the notching. Please if you can accurately do this, measure between the carriges/stringers through the hole you have in the drywall, then see if the same measure is between the skirt boards on the carpeted side. If it is housed, it will be the same, if the are not there will be about a 3" difference.
    – Jack
    Feb 14, 2018 at 23:24
  • 1
    @isherwood, the OP is wanting to take down the existing balustrade and the short wall that supports that type of install, shorten the walls so the treads can cap over them and the balusters will set on top of the extended tread and not the wall cap that is there now. IMHO, that will be a nice touch, I have done that before, but not with housed stringers. You may or may not concur, but the clue I seen thinking housed stringers is the amount of material left at the notching. Cut stringers usually leave about 5-6" of material. Housed stringers leave about 1 1/2-2", as seen in the pic.
    – Jack
    Feb 15, 2018 at 3:11

1 Answer 1


You can do what you want, even if they are housed but you will need to loose the ceiling material or move the stair treads ahead about 6". you could easily do that on the short lower run, but not so on the upper run.

You will need access to the upstairs after the stairs are gone, this may take 2 days to do, especially if you are a novice, maybe even 3. Seasoned carpenters really should be doing the work.

If the lowering of the ceiling is a deal breaker for doing it, no need for me to write anymore. I see no issue with lowering the ceiling 4 or 5", the square corner that projects below the sloped section in one of your pictures will still be lower than the new dropped height of the stairwell. If you feel you have enough experience to tackle this, please say so and I will edit the post if need be, but it is pretty much a gut and replace. Leaving anything in of the original will only slow down the new install or weaken what you add over it.

  • Thanks Jack, I have taken on a number of renovation projects around our house and feel confident that I can do this.
    – M. Markson
    Feb 15, 2018 at 14:54
  • I've got lots of time and flexibility on this one. Your comment "its pretty much a gut and replace" is what I needed to hear. I just wanted to make sure I wasn't missing something obvious and needlessly doubling my work.
    – M. Markson
    Feb 15, 2018 at 15:04
  • One more quick question re: number of stringers... I was under the impression that for a ~36 inch wide staircase like ours, 3 stringers was essential to prevent bouncing. However, we have only 2 stringers and they are very solid. Can 2 stringers be used with a hardwood tread if the hardwood is thick enough? 1.5-1.75"??
    – M. Markson
    Feb 15, 2018 at 15:45
  • The reason 2 stringers is adequate here is because they're (presumably) anchored to the walls at intervals. Two wouldn't span that run in the open unless they were doubled, at least. If the riser carries the tread and there's minimal flex at the back of each tread (as I'd expect with 5/4 oak), no problem.
    – isherwood
    Feb 15, 2018 at 16:30
  • I typically run 3 carriages on this type of system. Mainly to keep the joint where the riser and the back edge of the tread meet to keep it from "working". There is not a lot of pressure in this area typically, tho' it does happen on occasion. I have also seen companies that build prefab stairs use a metal angle at the area to reinforce this area. If you like to "play", you could tongue the top back edge of the tread and groove the riser with a 1/2"X1/2" dado, leaving 9/16" or so for the tread tongue to bear on and glue it together. This is how I like to do such things. I like to play.
    – Jack
    Feb 15, 2018 at 18:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.