I am looking for any help or guidance that can be provided on removing a cracked/split stair tread in my 1920s colonial. It appears that several steps have split along the glue joint line and I would like to repair or replace these. I am hoping to remove the treads without destroying them in the hope of re-ripping, re-jointing and re-glueing them and saving as much of the original wood as possible.
The step is recessed in a mortise cut into the wall-side stringer. A dado on the underside of the front of the tread fits over the riser but I do not see anything holding the back of the riser down other than nails into the stringers. I removed the balusters and used a reciprocating saw to cut through the nails that go through the top of the tread but I can't seem to get the tread to move very much (I can lift the baluster side of the tread 1.5" or so, but that is it. I do not have access to the underneath of the stairs.
You should be able to lift the tread and shine a flashlight in there and see that the back side of the tread that is mortised into the stringer will have a wedge drove under it. The mortise is made with a slight taper and when they install the stairs they work from the top down and install the tread into the mortise and then drive the wedge in to make a tight joint. Usually some glue and toenailed finish nails are also installed which will make for a tough removal. The only advise that I can give is to carefully pry up on the tread from the balluster end and try to pop it loose from the mortise but this may break something if not done slowly and carefully.