QA

Question: How Thick Should Cement Board Be Under Tile Floor

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.

Can you use 1/4 cement board on floors?

Both 1/4- and1/2-inch cement board are appropriate for floors. To install cement board on floors, cement board manufacturers mandate a 5/8-inch plywood subfloor or OSB underlayment.

Do you have to put thinset under cement board?

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.

Do you put cement board under tile floor?

If you’re working over a wood subfloor, cement board is the right choice for your tile base. Because plywood expands and contracts beneath the ceramic tile, grout and tile failure (loose tiles and cracked, crumbling grout) is just a matter of time.

What is the thinnest backer board for tile?

A vertical backerboard over which you plan to tile should be at least 1/2 inch thick.

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. Along the perimeter, screws should be installed at least ½ inch from the edge, but no more than 2 1/4 inches.

Do I need 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.

Which side of cement board goes up?

The smooth side is ideal for mastic applications, as it increases adhesive coverage. The textured side is ideal for mortar applications, as it enhances bonding and reduces tile slip. That said, mastic or thin-set mortar can be used on either side of the board without compromising performance.

Do you put cement board under a shower pan?

ALL CEMENT BOARDS MUST be installed in a fresh bed of thinset. Unmodified thinset is preferable. If you want the cement board under the shower tray then do so – doesn’t matter. If that creates plumbing issues you can’t deal with then leave it out.

How long should cement board screws be?

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.

Do you put plywood under cement board?

The Surface Below the Cement Board Flooring: For ceramic tile floors, the cement board usually rests on a plywood subfloor (minimum 5/8-inch-thick exterior-grade plywood or OSB). Instead, first, remove the existing surface material, then install the cement board over the studs and membrane, as applicable.

Which is better cement board or Hardibacker?

HardieBacker is much more light, and it is also the best selling brand of cement board available. It is much cleaner because it does not have any glass in it. It allows for a smooth job with minimal mess. As a bonus, HardieBacker board has an EZ Grid pattern so you can cut perfect lines.

Can you tile directly on 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 tile directly on drywall?

As long as your wall is smooth and flat, you can install a ceramic tile kitchen backsplash directly over drywall or plaster with no problem. Start by cleaning the wall to remove any grease, then apply thin-set adhesive, and set the tile. After the adhesive has set, apply grout, and you’re done.

Can you tile over old cement board?

Cement Board Ideally, tile should be installed directly on top of a surface like cement backerboard, which is stable enough to handle the tiles. Backerboard is typically nailed or screwed to the subfloor with taped seams and a thin layer of thinset for support and can be installed over old thinset.

How many screws do I need for a 3×5 cement board?

Screw a full-size 3 x 5-ft. cement board to the back wall. Place special 1-1/4 in. cement board screws every 8 in.

Can I use deck screws for cement board?

Weight on the wallboard (Hardi) isn’t the issue with using the proper screws. The screws should be alkali resistant, galvanized deck screws don’t qualify. The issue is corrosion from the cement products.

Can I use drywall screws for cement board?

You don’t want to use regular drywall screws for cement boards. They can corrode, they can break down the edges of the boards, and they won’t drive in flush properly. Use ITW’s ROCK-ON and BACKER-ON screws instead.

What’s the best way to cut cement board?

Score-and-Snap The simplest way to cut cement backer board is to score the surface and snap the sheet along the scored line, similar to the way you’d cut drywall. In fact, you can use a drywall utility knife to score backer board, but a better option is a carbide-tipped scoring tool.

What cement goes under shower pan?

The ideal mortar is a mix of standard cement mix with sand and Portland cement, which creates a great water-resistant barrier that can support the weight of the shower unit. Quikrete explains that it works well for shower pans, being a mix of Portland cement, graded sand and other proprietary ingredients.

Can I use thinset for shower pan?

Re: Shower pan and thinset? yes. They will project over the flange and keep it in place until the walls are finished. After that, NOTHING should be able to move it.

Do I need mortar under shower pan?

Designed to drain water from the shower, it protects your floor from water intrusion, rot and mold. Installing one requires some skill and there are certain rules and procedures to follow when doing so. In some cases a mortar bed is a necessity; other times it isn’t.