[oscarMadison]

I'm in the process of pulling up the old hardwood floor from two bedrooms. So far the subfloor, 3/4 diagonal boards, looks in good shape. Course the guy who put the old hardwood floor down only used one nail every 18 to 24 inches. At this point the only thing I am seeing is a few nails have risen about a finger nail thickness. Basically a few squeaks when I walk on it but not many. For the squeaks my plan is to add some screws to the tighten down the boards. Will I need to pre-drill or counter sink for the screws?

 

[Just Bill]

Either countersink them or make sure they pull down below the surface, nothing sticking up on the subfloor. What is going over the subfloor. If tile you need 1/2 backer board, glued and screwed. If new hardwood, use a layer of rosin paper to isolate the two floors and reduce squeaking.

 

[oscarMadison]

Thanks. It'll be new hardwood floor. I'll use the rosin paper.

Don't know what the other guy did when he put down the hardwood. The old floor had waves. Boards were loose, I could even move a few with my shoe. One board wasn't even straight, not warped, but like it had not been run through a jointer before they cut the T&G.