Resurfacing OSB subfloor?

[Jim Becker]

What you propose would be difficult. If the subfloor is otherwise stable/safe, and since it's well, a subfloor, it doesn't need to be pretty. Fill the divots with mastic or something and if you really feel the need, cap that with 1/4" material before moving on to your new floor surface.

[johnny means]

I wouldn't spend any effort on trying to salvage a $10 sheet of OSB. Cut it out and throw in a new piece.

[mreza Salav]

cut it into smaller pieces with shallow cuts, remove screws and clean the glued areas to I-joists. Put a new one down with glue/screwed to joists. Cleaner/better job.

[Carol Schnell]

I live in a house built in the 40's. I decided to get rid of the carpet in a bedroom so I could glue down engineered flooring. Under the carpet I found ¾ " diagonal plank yellow pine wood with gaps between the boards. There is a crawl space under the house with high quality plastic as a moisture barrier over the dirt. Should I remove the plank and replace it with 3/4" plywood? If I add plywood over the plank, the floor will be considerably higher than the adjacent wood at the doorway. The floor is relatively flat and would need minimal leveling. Is Ardex cement-based underlayment the best product for that? Do I need an underlayment paper or felt over the plywood? Do I need to silicone the cracks between the plywood? As you can see, I need lots of advice. I appreciate any help you can provide. Thank you.

[Jim Becker]

Carol, there is no need to remove the plank subfloor if it's structurally sound. You should use whatever the engineered flooring manufacturer specifies between the subfloor and the engineered flooring you choose as many products have some form of preferred underlayment that provides cushioning, etc. That will effectively close any of the small gaps in the existing subfloor. Now if that subfloor is in poor condition where more than limited repairs are required, it might be worthy of replacing it with modern materials.

[Tom Bender]

Hi Carol
What Jim said is solid. And,

It's important to keep the outside out of your crawl space. A bug inspection is money well spent. Maintain your gutters and lot drainage. Previous owners may have been vigilant and you can not afford to do less.