Installing Backer Board On Floor For Tiling

Installations for floor tile and other horizontal surfaces like countertops require an extra step of applying thin set tile adhesive to the wood subfloor before laying down the cement board sheets.

Installing backer board on floor for tiling.

Whenever you re laying tile on a wood subfloor you need to first install cement backerboard to prevent leaks and water damage. Cement board is the most durable trouble free tile backer for tub surrounds showers floors and all other wet areas. Install a cement based backer board following the manufacturer s instructions. Its made from cement and sand and is reinforced by fiberglass mats on both sides so it s impervious to water.

Cutting fastening and taping and mudding. Unlike wood or drywall sub surfaces cement backerboard will not rot warp or grow mold and mildew when exposed to water. Never install new tiles over existing tiles or onto an unprotected wood or plywood floor. This provides a solid surface under the tile that prevents flexing that could lead to cracking.

First changes in humidity make solid wood shrink swell and cup more than plywood. For flooring the backer board should be installed over a 5 8 inch thick osb or plywood base. Use a polymer modified thin set a type of mortar to attach the backer board to the subfloor. Thick 3 x 5 ft.

For countertops use 3 4 inch plywood beneath the backer board. Using a notched trowel apply a leveling bed of thinset mortar over the subfloor and embed the backer board sheets into the adhesive. It s typically available in 1 2 in. Installing over wood.

Installation of cement backerboard is always preceded by application of thinset mortar which fills low spots in the subfloor and anchors the backer board sheets. Second the strength of wood boards isn t always consistent. Add more mortar as necessary to fill sunken areas in. Spread the mortar to about 3 16 thickness.

How to install tile backer board. Cement board commonly sold under trade names such as durock hardiebacker and wonderboard is now the standard underlayment used for ceramic porcelain or stone tile laid with thinset mortar adhesive cement board is used for most floor tile and has all but replaced plywood and drywall backer materials for wall tile applications in wet areas like showers and tub surrounds. To install ceramic tile over wood the wood surface must be structurally sound enough to support the weight of the tile. Half inch cement backer board is ideal for most tiling jobs including walls floors countertops and ceilings.

Use a trowel to spread the thinset but before you do that be sure you ve scraped off old adhesive from any existing flooring you removed and vacuumed and cleaned well. According to backer board manufacturers and tile setters installing backer board directly over an old solid wood subfloor is risky for a couple of reasons.