What do you use to seal cement board when tiling?

Their online instructions/diagrams show no use of a vapor barrier. You should, so that any moisture that gets behind the cement board runs into the tub or shower instead of into your wall cavity (causing rot or mold/mildew).

It's best to use the cement board screw, but a deck screw will do just fine. ... Use screws designed for cement board like Rock-On screws. They start easier than drywall screws in CBUs. They're easier to use, don't rust as easily and hold better.

Cement Board and a Liquid Membrane No plastic sheeting goes behind the cement board.

A liquid waterproofing membrane, such as RedGard or Hydro Ban, is applied to the cement board and allowed to cure.

Then, tile is installed over the membrane..

We recommend applying three to four coats of the SILOXA-TEK 8510 penetrating concrete sealer wet-on-wet. The Siloxa-Tek 8510 concrete sealer will help to reduce moisture seepage, prevent mold and mildew growth and it is the best solution to help seal a concrete fountain or birdbath.

Yes, HardieBacker® 1/4" Cement Board is deemed noncombustible when tested to ASTM E 136 and can be used in conjunction with other noncombustible materials around a fireplace. ... However, using fiber cement board like Hardieboard is acceptable in locations including the mantel and fireplace surround.

When you buy cement board it requires the same installation materials as drywall but with a twist. ... Instead of using drywall joint compound to embed the tape in the cement board you should use thin-set mortar. We utilized the same thin-set that will be used to attach the tiles.

Yes, silicone will stick to cement board.

In fact I highly recommend that you use cement board such as 'Durock' as your backer board.

Use proper screws.

Such as the specific cement board screw..

You can also use a carbide tipped cutting tool similar to a utility knife to cut the cement board. Use a compass to draw the hole and use the cutting tool to score the board on both sides, then pop it out with a hammer.

1/4" Durock cement board should not be used for wall or ceiling applications. For wall or ceiling applications, use 1/2" or 5/8" Durock cement board. If you have 3/8" sheetrock, use 1/2" cement board and feather out the joint to approx 10" to 12". It should be almost unnoticeable if done right.

No. You will need actual subfloor (3/4 osb or ply) below the cement board to support it. And you'll only need cement board if you're laying tile. Cement board alone will be far to soft, among other problems.

Cement Board and a Sheet Membrane Kerdi can also be installed directly over standard drywall in a shower because, when installed correctly, it creates a continuous waterproof barrier..

Regular drywall is not appropriate. Many professional installers even recommend against using water- or mold-resistant drywall in high-moisture areas. In sharp contrast, cement backer board does not rot, warp, grow mold, or deteriorate when subjected to water.

In short, tile and grout are not inherently waterproof. ... 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.

Tiling on plaster is ok, as long as your not fitting large format tiles. Still prime the plaster (obviously when dry) with acrylic primer. NOT PVA. Why plaster though.....not really necessary.

If you sort the plasterboard out level/flat.........you don't need to plaster it at all....... tile directly onto the plasterboard, because if you are not experienced in plastering, you could end up in a worse state. Sort the plaster board, it's not that heavy.......then prime with acrylic primer.......then tile it.

Do I need to prime HardieBacker® board before I tile onto it? No. HardieBacker tile backerboard is ready to tile once installed, just wipe down with a damp sponge to remove any dust prior to tiling.

Short answer. No, never use PVA to prime a surface before applying tiles. The acetic acid produced when cement and PVA come into contact would render the adhesive and grout useless. Scroll down for a longer answer!

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..

If you are painting interior concrete it is vital to seal the concrete. This will prevent moisture from seeping in underneath the paint and causing mold. Use a masonry sealer and follow the manufacturer's directions on how many layers to apply and when.

If you are painting interior concrete it is vital to seal the concrete.

This will prevent moisture from seeping in underneath the paint and causing mold.

Use a masonry sealer and follow the manufacturer's directions on how many layers to apply and when..

Yes, the plaster needs to be sealed as it is very porous and will suck the moisture out of the tile adhesive before it has time to 'grab' properly.

While you don't always need to seal backer board, it sometimes make sense to do so. If you are installing backer board in an area that will be subject to a great amount of moisture, like in a shower, then it makes sense to put a waterproofing sealer on it.

Yes, silicone will stick to cement board. In fact I highly recommend that you use cement board such as 'Durock' as your backer board. Use proper screws. Such as the specific cement board screw.30 Sep 2015

Do not use cement board on its own. Your shower will leak and you will be tearing it out within a year.

Half-inch cement backer board is ideal for most tiling jobs, including walls, floors, countertops, and ceilings.

For flooring, the backer board should be installed over a 5/8-inch thick OSB or plywood base..

Use thin-set mortar when installing cement backerboard. Thin-set dries slowly, allowing you to fix and readjust backerboard sheets as needed. With the smooth side of a 1/4-inch notched trowel, spread enough mortar for one sheet.

Use a carbide-tipped wood-cutting blade to minimize dust. Cement is a very hard material, so you'll need to use a blade that can handle the material. Carbide-tipped wood-cutting blades have fewer teeth than other circular saw blades and the carbide can withstand the strain of the cement.

Yes, silicone will stick to cement board. In fact I highly recommend that you use cement board such as 'Durock' as your backer board. Use proper screws.

Position each piece of backer board in the thin-set, press in place, and attach using special backer board screws on the spacing recommended by the backer board manufacturer.

Cover the joints in the backer board with fiberglass tape embedded in thin-set adhesive and allow to set before tiling..

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..

Caulk the gap Ideally, you would leave a 1/8 inch gap which would then have the sealant applied to it. Either stopping the cement board above the tub flange or alternately shimming it out and dropping it down near the tub would both be good options.

To seal concrete floors, use an epoxy sealer if you want something durable that comes in a variety of colors. For indoor concrete floors that won't be exposed to oil or grease, use an acrylic sealer, which is easy to apply. If you want to seal over concrete floors that already have a seal, try a polyurethane sealer.

7. Apply the Sealer. After cleaning, patching, and repairing the concrete floor, you'll be ready to seal it. This process creates a protective layer that prevents moisture from seeping through the concrete and into the tile floor.

PVA isn't good, don't use it with any form of tiling... You should seal the floor with a suitable primer that is compatible with the adhesive you buy. i.e. buy Ardex primer for Ardex adhesive, BAL primer for BAL adhesives...

Use thin-set mortar when installing cement backerboard. Thin-set dries slowly, allowing you to fix and readjust backerboard sheets as needed.

A self leveling compound can be applied to most types of subfloor materials. You can apply self leveling compound to plywood, osb, concrete, cement board, hardibacker and many other types of subfloor materials. You can also use self leveling compounds when installing tile over top of an existing tile installation.

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.

cement board screws spaced every 4 in. 4. Tape the seams Lay cement board fiberglass mesh tape over all the seams (it's sticky on one side). Use a wide putty knife or a flat trowel to spread thin-set mortar over the tape, making sure to knock down any ridges or high spots.

Use special mesh tape on seams Cut drywall to fill in between the existing wall or ceiling and the cement board. Screw the drywall to the studs. Cover all of the corners, joints and seams, including the joint where drywall and cement board meet, with the fiberglass mesh tape.

Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used.

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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..

DIY Doctor gets many emails saying that PVA should not be used on walls before they are tiled.

This is simply not true.

...

PVA can be used to seal any type of porous surface,including plasterboard and if it is done properly it will give you a much much better job than working on unsealed walls..

You do not have to use a cure and seal, but it is important to seal your concrete. ... Sealing your concrete will protect it against damage and deterioration against water absorption and surface abrasion. Sealed concrete is more resistant to: Cracking, spalling, and pitting.

Do not use cement board on its own.

Your shower will leak and you will be tearing it out within a year..

Cement backer board is mainly used as a sub-surface for tiling. 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.

Acrylic paintFor cement boards that have already been primed, 100% acrylic exterior paint is recommended. Acrylic paint is the best choice for cement board. It's especially important if you are working with new cement board to avoid oil-based primer.

Cement board is not waterproof. Hardibacker is not waterproof. Tile and grout are not waterproof. Cement board will not fall apart when exposed to water.

If you are going to tile over the cement board, you should tape the seams. This should not be that difficult. Pack in thinset, lay on the tape, and flat-knife to get it set in. ... If you just want to leave the corners untreated that will probably be fine, because that seam won't split the center of a tile.

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.

Tape the seams with mortar Cover the tape with a skim coat of thin-set mortar, squeezing it through the tape to fill voids and cracks.

Remove any excess material before it hardens.

When you're done covering the tape with thin-set, you're ready to tile.

You don't even have to let the thin-set dry..

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.