I'm replacing about 130 sq ft of 12x12 peel and stick vinyl tile with another peel and stick tile. I've pulled up the old peel and stick and the 1/2" plywood subfloor looks good, solid, well nailed in, joints leveled with leveler. The question is...after I've pulled up the old peel and stick, there is a bit of sticky residual adhesive left behind. It's not enough to make it unlevel. But, will it screws up the new peel and stick staying down? I don't see getting the residual adhesive up with a razor knife. It's just too many square feet to do that. I also don't want to have to lay down another 1/4 plywood subfloor if I can avoid it. I was going to try beltsandingwith 60 or 100 grit. I was also wondering if there was a primer I would use or maybe adding a bit of extra adhesive to the new peel and stick. Any thoughts? I'm literally halfway through tearing the old ones up, so could use some guidance.

I have to replace some flooring that has water damage. My floor is ¾” tongue & groove with .200” thick (13/64”?) underlayment over it. The original underlayment was nailed down with nails about 2” long and spaced about 18” apart. Those nails seem a little long to hold down something that thin. What’s recommended to hold this down? Adhesive backed vinyl tile will be going over it. Thanks.