Do I need plywood under cement board?

Because cement board can be used either for floors or walls, the surface below the cement board will vary: Flooring: For ceramic tile floors, the cement board usually rests on a plywood subfloor (minimum 5/8-inch-thick exterior-grade plywood or OSB).

Do you put anything under cement board?

Thinset is going to create a solid surface under tile and prevent flexing that could lead to cracking. Using thinset between the backerboard and subfloor will create additional strength, fill in any potential gaps that exist and lessen the possibility of movement.

Can you use cement board instead of plywood for a subfloor?

When properly installed with a coat of thinset beneath it, cement backerboard won't flex like plywood, and won't contribute to problems like lippage. This makes cement backerboard a good choice for large format tile floors, as well as for older homes that may have more uneven subfloors.

Can I just screw down cement board?

Doing this will require that you remove the existing surface material before installing backer board over the studs. Cement board can also be used on countertops when laying tile. However, the process will involve using an extra sheet of backer board. Never use standard screws when installing cement board.

Do you need plywood under durock?

Subfloor should be minimum 5/8" APA span-rated plywood or OSB with an Exposure 1 classification or better. Minimum 3/4" APA span- rated plywood or OSB with an Exposure 1 classification or better. Cover base with USG Durock™ Brand Tile Membrane, 15 lb.

DUROCK Cement Board Do's and Dont's

Do you need plywood behind Hardie board for shower?

That seems like a lot. I think you could use 1x6 if they're spanning 16" or 24"...but, no, you do not need plywood too, but yes, you should use cement backer board, unless it's a shower, then I wouldn't use thinset.

Can you put cement board on joists?

Do not install HardieBacker Cement Board on joists more than 24” on center. If your floor meets the requirements, the next step is to ensure that it is structurally sound and free of damage. Replace any warped, missing, or uneven sections of flooring so that you have a flat and clean surface.

Can you lay cement board without Thinset?

Not only is thinset a critical component underneath cement board but the other critical component is the fasteners. And you won't have the fasteners if you are trying to install it over concrete.

Can I use 1/4 cement board on floors?

1/4" USG Durock® cement board is an ideal substrate for floor and countertop ceramic tile installations. The 1/4" thickness helps eliminate transition trim when abutting carpet or wood flooring and minimize level variations with other finish materials.

Do I need to seal cement board before tiling?

Although most backerboards currently available won't fall apart when exposed to moisture and are somewhat water-resistant, they aren't waterproof. To prevent moisture from seeping through to the wood or metal studs beneath the tile, a barrier or sealant must be used on porous materials.

What is better cement board or backer board?

Backer board helps ensure a durable, long-lasting tiling job. It helps prevent cracks in the tile and grout due to moisture, humidity and temperature. Cement backer board is sturdy, waterproof, and an ideal substrate for any tiling job, inside or outside.

Can you tile directly to plywood subfloor?

Tile can be laid on plywood. But do not install tile directly on the plywood subfloor itself. Use an intervening layer of a sheet of thinner plywood.

Can you put cement board over OSB?

The cement board must have a layer of thinset under it, use a 1/4" square notch trowel, and then anchor the boards with galvanized roofing nails or backerboard screws. The thinset is under the board to fill in the voids much like you talked about with the OSB, it is not for bonding, it is strictly a filler.

Can you put cement board over drywall?

(Some cement board products may not require the underlying membrane if the seams are properly waterproofed.) In such wet areas, never install cement board directly over drywall or green board. Instead, first, remove the existing surface material, then install the cement board over the studs and membrane, as applicable.

How long before you can walk on cement board?

This is normally 12 hours but may be up to 24 hours in some cases. After the mortar is dry the backer board is ready to receive the mortar for the tile.

Can you put cement board over plank subfloor?

The best method is to refasten the subfloor, then add a layer of plywood. 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: First, changes in humidity make solid wood shrink, swell and cup more than plywood.

Can you staple cement board?

There is a 1/2” crown on the 18-gauge coated stapler. Minimum 1-1/4” long roofing nails or ribbed countersink screws are required for HardieBacker 500 cement board. The chisel point stapler must be at least 7/8” long and coated in 18-gauge.

What kind of screws do I use for cement board?

Cement board attached to plywood or similar underlayment will hold with only 1 1/4-inch screws; for thick or heavy metal fixtures, use 1 5/8-inch screws. In general, 1 1/2-inch galvanized nails will hold the board firmly in place.

Can I use liquid nail on cement board?

LN-907 Liquid Nails is recommended for cement board and most other common building materials. The application temperature is from 22 to 120 Fahrenheit and the service temperature is -20 to 140 degrees Fahrenheit. This makes it ideal for just about any DIY project and on most construction projects.

Can you put backer board over plywood?

When you come up against plywood subfloors in the bathroom or other areas of the home, a cement-based backer board must be installed on top of the wood. This provides the tile with a proper installation surface to bond with, offering you the lifetime guarantee that a good tile installation will always provide.

Can you put Hardie board over plywood?

Use minimum 1/2 in exterior grade plywood or equivalent, positioned across the wood cabinet. Space between plywood supports is not to exceed 16 in on center. Do not align HardieBacker cement board joints with plywood joints.

How many screws do I need for cement board?

Q: How many screws do I need to put into a sheet of cement board? We recommend referring to the cement board manufacturers guidelines for screw pattern. In floor applications, screws should be placed every 8″”. You will use approximately 55 screws per 3′ x 5′ cement board and 91 screws per 4′ x 8′ cement board.

How thick should cement board be for shower walls?

The minimum recommended thickness for the shower wall is 1/2″ because like some of the other boards, they become far too flexible at thicknesses below 1/2″.

How thick should cement board be under tile floor?

Cement board is substrate made of cement and fiber. It comes in ¼” to ½” thickness and it is used as an underlayment for wall tile. Floor istallation requires that the total thickness of the substrate must be minimum of 1¼ “ prior to setting tile as per the TCNA / Tile Council of North America.