QA

Question: How To Install Cement Backer Board On Concrete Floor

Use a notched trowel to spread the thin-set on the concrete where your first sheet of cement board will be placed. Use the flat side of the trowel to spread the mortar firmly against the concrete to achieve a good bond, and then rake back across it with the notched side to leave ridges in the mortar.

Can you use backer board on concrete?

Cement backer board is often used as a tile base on plywood or OSB subfloor. Cement backer board on concrete as a subfloor or underlayment is usually not recommended or needed. In most cases, you can apply tile directly to the concrete.

How do you secure backer board to concrete?

Fasten the board to the wall with 2-inch concrete screws and a hammer-action power drill with a Phillips-head screwdriver bit. Activate the hammer action on the drill before driving the screws through the board and into the wall. This is usually accomplished by flipping a toggle or switch or turning a dial.

What kind of Thinset goes under cement board?

An unmodified thinset (Masterblend) is fine between the Hardi and the subfloor. Tara, The reason for the layer of thinset between the cement board and the subfloor is to fill the voids/gaps between the two. It’ll keep the cement board from moving up and down.

How do you install tile backer board on concrete?

Use a notched trowel to spread the thin-set on the concrete where your first sheet of cement board will be placed. Use the flat side of the trowel to spread the mortar firmly against the concrete to achieve a good bond, and then rake back across it with the notched side to leave ridges in the mortar.

Is backer board required for concrete floor?

Cement Board Not Necessary on Concrete Normally, installing cement board is not regarded as necessary when you are laying tile onto a concrete slab. Since this subfloor is already cementitious, adding a cement board layer would be redundant and even detrimental to the overall project.

Should I put thinset under cement board?

Using thinset under cement board is a commonly skipped step amongst many contractors. However, many manufacturers including, both Durock and Hardiebacker not only recommend that you use thinset under their backerboard, but they specify it and will void the warranty on their product if it’s not used.

Can you use 1/4 inch 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.

Can you tile directly over concrete?

A: It’s perfectly acceptable to put tile directly on concrete — with a couple of caveats. First, it is important to determine if there is moisture coming up from the slab. Those products should help prevent any cracks in the slab from damaging the newly installed tile.

Can you use Liquid Nails 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 I just screw down cement board?

Screw and Joints Do not use drywall screws as they are not recommended to be used to hold the backer board in place. All of your backer board pieces should be cut before they are placed on​ the floor. It is important to highlight that screws shall not be installed all the way down to the floor joists.

What do you do with a gap between tub and cement board?

Technically, after the tile is installed over the backer board that gap between it and the tub ledge should be filled with an ASTM C920 sealant (caulking e.g. silicone). Although some say you should have weep holes along this gap so any water behind can weep out into the tub.

What is the difference between backer board and cement board?

Cement backer board is also called cement board, and it’s the most commonly used backer board for all manner of ceramic and porcelain tiles. Made of cement and reinforced on the top and bottom with fiberglass, this waterproof backer board is generally used for tiled shower surrounds and floors in wet areas.

How do you screw cement board?

Drill cement board screws through the backer board sheets every 6 to 8 inches. Position the screws at least 1/2-inch, but no more than 2 inches, from the edge of the sheet. Drive the screws in so that the heads are slightly below the surface of the backer board sheet.

How thick should cement board be for tile?

Floors: A 1/4-inch minimum thickness is needed, but thicker panels are also fine. Walls: Use 1/2-inch or 5/8-inch-thick cement board, not 1/4-inch. The extra thickness is needed when spanning the studs and it provides a solid base for the tile.

Do you have to tape cement board seams?

The thinset and mesh tape are to strengthen the seams. If you are going to tile over the cement board, you should tape the seams. This should not be that difficult.

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 long before you can walk on cement board?

However, after you mount the backer board to the floor you simply have to seal the seams with mortar and wait until the mortar dries. This is normally 12 hours but may be up to 24 hours in some cases.

Do you have to seal cement board before tiling?

Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used. However, if you choose to use concrete backerboard, which is much stronger and more durable than gypsum board, a water vapor membrane must be placed underneath it or a sealant applied on top of it.