I'm doing a DIY project converting my carpeted stairs to stained 1" think red oak treads and painted poplar risers. My issue is at the top of the stairs where I'm placing a narrow stair tread, this stair tread then transitions to carpet. This top stair tread sits on top of the plywood sub-floor (existing carpet has been cut back) that the existing carpet is installed on. To make sure that this top stair tread is level I'm going to have to place shims under it, the plywood sub-flooring is not level. I'm concerned that this is going to create a trip hazard due to the height difference between the carpet and stair tread. New carpet will be installed, so some sort of transition piece can be used if possible. I believe here are my options to correct this:
1) cut the sub-flooring in that small area and replace it so the transition between the carpet and stair tread is level and acceptable.
2) bevel cut the back edge of the stair tread to minimize the height difference
3) use some sort of transition piece between the stair tread to carpet when new carpet is installed.
What is typically done in this situation? Any suggestions or comments would be greatly appreciated.
Thanks
Best Answer
If you happen to have a double-layer subfloor, remove the top layer and build back up under the tread using material of appropriate thickness.
Otherwise I would make the top tread thinner where it laps over the subfloor. You can do this a couple ways. Either use a hand planer and take multiple passes, or use a tablesaw or circular saw, shifting the fence 1/8" with each pass. Be sure to stop short of where the tread drops down to the riser.
Either approach has the added benefit of bringing the top rise back to standard. I would still use a small bevel against the carpet to make it easier on feet.
Note that the second option will weaken the tread. The nosing needs to be supported well to prevent cracking. Use shims and construction adhesive to create a solid bedding.
Regarding Ecnerwal's good suggestion of a full-depth tread extending past the door casing... Those are two different trim assemblies and shouldn't be expected to align. You could nip the corner off the tread at a 45 to meet the casing, though, or simply bevel both the edge and the end slightly and not worry about it. If you're able to get the tread low enough you may be able to leave it as you have it now, too.