That is, I could cut a rabbet in the nose. If I were to use new tread material, whether more OSB or even plywood, I could cut them the way I want. However, I discovered that not only are they screwed down, they are glued as well. I tried to remove a tread not too long ago so that I could take it to the table saw to rip off the nose. Something I had thought of since I first posted, I could replace the existing OSB treads. That's the main reason why cutting the existing nose off and just adding the new nose is not an option. I have been very cognizant of the depth of the tread that I end up with. And nails need to be fairly substantial such as 8 penny or above finish nails which leave noticeable hole to fill and disappearing color matching is impossible unless you are a master at it. That slightest difference can catch people's heels or socks or splinter up, leaving something that must be repaired.

Glue and nails are fine but close nails since you don't want even 1/32' of nosing warping up later.

But if you want it, nosing must not move later. You want the nosing because it looks better with the nosing. Also you can pre-stain the parts and just assemble the pieces carefully instead of using lot of fillers or such later. You can use mastic instead of thinset and directly on the board, maybe with a paint on redguard? Support the tiles until mastic dries. I'm picking up some words such as cement board and having to stain things later? This is a tile on risers which will see very little load on them. Sorry but can't create a picture from your description. But is adding a new piece in it's place the right thing to do? With construction adhesive and nails, is it going to be strong enough?ДЇYI: I plan on using grout caulk where the tile meets wood. Leaving the existing stair nose is a very unattractive option. It also shortens the the depth of the tread which is not really an option. From the notch to the edge of the nose is only 1/2'. It would also be 1/4' shorter than the existing nose overhang, giving less of a reveal underneath the nose.ДЄs you can see from the picture, if I just cut off the existing nose (of OSB) and put the new stair nose right on it, there is not enough overhand to compensate for the 1/4' cement board, 3/8' tile and whatever thickness the adhesive will produce. This gives me the 1/4' I need to add an 1/8' grout line above and below the tile and a good surface to stain to match the nose and hardwood. Even if I clean up the edge of the OSB (to take off the overspray from when the house was built), I'm left with an edge of OSB that will suck up stain, if I wanted it to match the stain I used on the stair nose.ДЄnother idea is to cut off the existing nose (of OSB) and add a piece of 1/2' red oak in it's place. Plus, I have no room for a grout line above and below the tile. If I put the nose on the tread, as is, I have 5/8' of OSB sticking out from underneath the stair nose. Given that we're using Talavera tile, the size can vary by 1/16' either way. Adding 3/4' flooring means there is basically 6' left for the tile. Between one tread and the underneath side of the nose above, it is roughly 6-3/4'. The existing OSB tread has a 1' nose on it.

I have 1/4' cement board that will go on the risers to affix the tile to. Notice the very short nose and shallow notch. This is the continuation of a project that has been on hold for the last 6 years.Д«elow is a picture of the stair nose. I will be using 3/4' hardwood on the treads and tile on the risers. I am in the process of redoing our stairs.

Tiled stairs