I'm a little fuzzy on the whole OSB subfloor thing. Sorry. I'm planning on installing 400 square feet of 3/4" x 3 1/4" maple over existing 5/8" waferweld SBA subfloor. It has a CSA 0437.0 rating. The joists are 2" x 8" on 16" centers. Is this subfloor suitable for a nail-down installation? Or do I need to add a layer of plywood? If so, what size plywood? Finally, has anyone ever heard of St. Lawrence hardwood?
What is the quality like? It looks pretty good, but this is the 1st time I have ever looked at hardwood, although I have looked at a lot of brands.

Thanks very much.

SB

Joists 16" OC is good! OSB only 5/8" thick isn't so good but it will probably work IF you install the flooring at 90 degrees (right angle) to the direction of the floor joists. If you want to install CDX plywood, either 3/8 or 1/2" will be fine. Staple the snot out of it. Can't use too many staples on underlayments. Unless YOU'RE the one tearing it out! Haven't heard of that brand of wood so no comment on it.

Thanks alot Gary.