Can Backer Board Be Put Over Squeaky Hardwood Floors?

Basics of Hardwood

• Hardwood floors are installed in one of two ways. The first is without any sort of underlayment beneath the wood, known as a floating wood installation. The second is hardwood flooring that is installed with a padding or some other form of material underneath it. Both cases involve flexibility and movement in the floor, although these are less if the floor is installed on top of a concrete slab.

Excessive Movement

• The basic principle of concrete and mortar is that they harden into a nearly impenetrable substance over time. They also have an inherent flexibility that can be increased with the inclusion of acrylics and latex compounds. But regardless of how much elasticity mortar has, eventually movement will cause cracks. Excessive movement can cause the tile to buckle and pop off the floor, which is what happens when it is installed on an unrated substrate.

Proper Substrate

• Hardwood flooring is not a rated substrate for use with ceramic tile or natural stone installations. This means you cannot install the backer board directly on top of the hardwood floor. Instead, you will need to build up the sub floor as if you were starting from scratch, including the appropriate thickness of plywood depending on if you are installing ceramic tile or natural stone. After these layers have been screwed in place, you can add your backer board.

Backer Board Installation

• The installation of backer board is simply to provide the tile installation with a platform for the mortar to bond to. It does not add to the overall strength and stability of the overall installation. The stability of a tile installation relies on the substrate, not the backer board underlayment. Since you cannot install tile on a flexible, moving surface, hardwood floors are never an acceptable alternative to plywood substrate.