Reducing The Width Of Stairs By Installing Posts Inside Stringers

by Joe
(Walden, NY)

I am planning on replacing my wood decking with Trex and have a question regarding the stairs. Attached is a picture of the stairs. The tread is 36" wide, with the posts and balusters mounted on the outside of the skirt board. Mounted flush on the inside of each skirt board are the stringers, which can't be seen from the picture. The concrete slab is 46" wide.

My plan is to install the new posts on the inside of the stringers, with the treads notched around the posts. In essence, the treads will still measure 36" wide, but the new position of the posts on the interior of the stringers will seem to shorten the overall space between both railings.

Is this still appropriate? What other options may I consider that could be more appropriate?

---

Editor's Comments
You can certainly build your railing or newel posts so that they are set on the inside of the stair stringer. However you must still have at least 36" between the face of opposing newel posts as a clear travel area down the stairs.

Check out this diagram. It shows a common stair tread configuration. So you would have to ensure the treads are wide enough to account for the width of the two posts.