Thanks for the reply Henry. I don't want to take the old treads off because the stairs are a prefabricated unit....glued, stapled, nailed,wedged, etc....I don't want to destroy the strength of the unit. Also, the treads are embedded about 1/4" in the 'knee wall'? (Hope I'm using the correct terminology.) Would it be possible to securely add a 1" bullnose onto the existing treads? Maybe with biscuits, screws and glue??