Charlie: Mike in Victoria writes, “I’m putting a new subfloor on a pier and beam foundation. Do I need a vapor barrier between the floor joist and the plywood? The house was built back in 1926.”
Tom: Absolutely not. Don’t do that. What I want you to do between the structure and the plywood is use construction adhesive and glue them together before you nail or screw down your subfloor. That’ll eliminate all the squeaking and give you a good bond and give you a stronger floor.
Charlie: On the subfloor?
Tom: Yeah. You do it on the top of the joists and then you put the subfloor down on the joists and glue it and nail it and screw it and that glue will bond it down, construction adhesive.
Charlie: Okay. Not Elmer’s glue.
Tom: You could use that but I don’t think I would. It’d be kinda messy.
Charlie: Or super glue. Use Gorilla Glue.
Tom: Super glue.
Charlie: Use Gorilla Glue.
Tom: No. Gorilla Glue expands like it’s … aw, man, that stuff … You gotta be careful with that.