Home>Discussions>BATHROOMS>The mystery surrounding backer board
5 posts / 0 new
Last post
The mystery surrounding backer board

Do I really need to install backer board?
I'm getting conflicting advice from everybody I ask about this.
Some people say it's an absolute must but others claim it's a waste of time and money. I've gutted my bathroom and installed a brand spanking new plywood floor that's smooth and level, I just don't want this to be an issue at a later date.
Thanks for any advice!

Re: The mystery surrounding backer board

I assume this is for the floor and not the walls...
What is the total thickness of your flooring? If it about an inch and a half of plywoood and the floor has absolutly no "give" or flex to it then maybe you dont need it, but I would just do it anyways. It wouldnt be much fun if your grout cracked and you had to tear everything up and redo...

Re: The mystery surrounding backer board

We installed cement tile backer board in our bath remodel for the floor and the shower walls. Anywhere tile would touch. It really is something that needs to be considered in the initial planning along with the plywwod subfloor thickness so the floor height matches the other flooring heights at the doorways. If your plywood is screwed down very well and your floor height cannot be raised without causing other problems you are probably okay. It is just the preferred backing for tile these days.

Re: The mystery surrounding backer board

Tile has been used for thousands of years placed over stone and remained there for ever. In our modern building practices with wood sub flooring that flexes as you walk on it the tile and the grout many times are stresses beyond there ability and therefore crack. To reduce the possibility of the tile and grout from cracking and to promote adhesion of the mortar base, backer board is a must. You should also know that in a large bathroom you may need to ad additional support to the floor to compensate for the added weight of the tile and mortar and backer board; this would be in addition to the backer board.

For showers I do not use backer board, I use a product by Georgia Pacific it is yellow in color, it is mold and mildew resistant and accepts mortar and tile. Unlike backer board that is made from cement and is porous the GP material is not so it will not convey moisture through it like backer board will. It also cost less than backer board.

Hope this is of some help

Re: The mystery surrounding backer board

yes do it. As the previous poster has stated tile has been applied to stone for thousands of years but...

The previous owners installed tile on the floors of my master bath, and the kitchen within the last 5 years and I have cracked tiles in both areas and I have a concrete slab foundation

The kitchen was applied directly over the old linoleum.

The bathroom was applied directly to the slab.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.