On Sun, 25 Aug 2019 13:33:12 -0400, Hawk wrote:

I am removing the treads from my basement stairs, which are the typical
basement 2x10s at 36" width and carpeted. I will be replacing the 2x10s
with 1" Red Oak. The 2x10s are recessed in the stringers for support on
each side and no other support. I will be adding a skirtboard to cover
the stringers, covering the risers with 1/4" oak plywood then inserting
the 1" oak treads. I will use support brackets on each end of the
treads, but my concern is support along the treads. If I only use the
brackets on the side, will the treads be spongy/bouncy in the middle and
eventually warp over time. Should I use support along the back of the
treads and if so, what are suggestions? 34" angle brackets? Or would it
be better to add 1/2" to 1" support board under the oak treads, though
the only problem with that is the treads have a rounded nosing and the
support boards would be visible? Suggestions?
Glue the oak terads to baltic birch ply sized to bring the thickness
to the same as the 2X (or the next thicker if necessary and rabbet
them down to fit) - this will give you a tread that is stronger and
stiffer thanthe original tread. 1 inch oak alone is NOT sufficient.
You could keep the plywood back far enough that the rizer covers the
face of the plywood. Do not be tempted to just put re-enforcement
between the stringers - like cleats.