floor tile - Question about subfloor?

Cathy Hamm · 10-06-2012, 08:30 AM

I have taken up a damaged subfloor in a small bath. Do I need to replace subfloor, even if I'm using backer board too. Can the cement backer board act as subfloor?

JazMan · 10-06-2012, 08:04 PM

Absolutely not, concrete backer can not be the subfloor. Please tell us more in detail.

Jaz

Cathy Hamm · 10-06-2012, 08:13 PM

Thanks for your reply and info. Why do I still need to install a sub-floor below the cement backer board that will have tile on top? Thanks!

joecaption · 10-06-2012, 08:20 PM

Tile board used on a floor is only 1/4 and offers 0 strength. It's just to bond the tile to.
Your going to have to let us know several things. What's on the floor now for a subfloor and underlaymant. (thickness and what it's made of)
What the width and spans of the joist are.
All very important when it comes to a tile floor.

JazMan · 10-06-2012, 10:18 PM

Cathy,

I was hoping you'd have supplied some info so we knew what you've got and how to proceed. For all we know what you're calling a subfloor may be your underlayment in which case it's possible to do what I think you wanna do.

If you were thinking of replacing the subfloor with concrete backer, you'd end up in the basement with the first step bruised and dazed.

Please answer Joe's q's and also include the joists type and size, spacing and unsupported span. And of course what is over the joists, how thick and how many layers etc.

Jaz