I have 60' of 1" thick by 12" wide red oak stair treads with one bullnosed edge which I'll cut down to make 15 treads for my new stairs. Each tread will be about 40" long. I rough framed the stairs assuming 3/4" thick material. I could use the treads at the full 1" thickness and only be 1/4" off at the top and bottom step, and code allows for a 3/8" step-to-step difference. But I'd like it to be closer than that.
I was thinking of cutting a very wide rabbet in the tread material such that it's 3/4" thick, but leaving the original 1" thickness on the leading 1 1/2" where the bullnose is. That would end up looking like a very wide version of red oak flooring bullnose without the groove, which would have the additional benefit of overlapping the top of riser making for a very tight joint. Sketchup image of the original and the desired attached.
I have a table saw, 12" combination jointer/planer, and a router table. I've considered doing it with multiple passes of a dado blade, or on the router table with multiple passes of a 1" router bit, but I'd have to somehow do it as a dado so I'd have support on both edges and then maybe finish it off by turning it 90 degrees for the final pass. I was wondering if anybody had a better idea. Someone mentioned to me a technique using the jointer, but for the life of me I can't imagine how I'd do it on the jointer. It's the Hammer A31 if it makes any difference.
stair treads.jpg