Had to choose between a 3/4 inch plywood subfloor or 1/2 inch with an extra layer for a big tile job

The old floor was uneven and the homeowner wanted 24 inch porcelain tiles. I could either tear out the old subfloor and put down new 3/4 inch plywood, or add a layer of 1/2 inch on top of the existing. I went with the 3/4 inch new plywood because it gave me a perfectly flat start. It cost about $400 more in materials and added a full day of work. The install went smooth and the floor feels solid as a rock. Anyone ever gone the other way and added the extra layer on top? How did it hold up?

2 comments

2 Comments

kevin_murray881mo ago

Man, a buddy of mine tried the add-on layer route last year. He put half inch over his old kitchen floor to save time. He said it felt okay at first, but after a few months some of those big tiles started to get a little hollow sounding in spots. He's pretty sure there was just too much flex hiding under there. He told me he wishes he'd just ripped it out like you did.

josephs261mo ago

Yeah, that sounds about right. My own shortcuts usually come back to haunt me too, just ask my last DIY project.