I plan on replacing the 2x10 treads on my basement stairs with 1 inch thick hardwood. This will make a one half inch gap at the top of the stairs where it meets the first floor landing. This seems to be a trip hazard. Should I shim each tread surface of the stringers with one half inch plywood to make up for the difference in height?
Yes you can add 1/2" plywood to all carriages/stingers to make up the 1/2" difference. Glue and a few small nails to hold it in place while the new treads go on is all you will need. Do not spare the glue/construction adhesive.