Best answer

You still need a vapor barrier with cement board, although in this case the barrier can go behind the board. Cement board is heavy enough and breathable enough to take the moisture without a problem. By having the vapor barrier behind the cement board you stop the moisture going further into the wall.

Answered by: Spacedman Date created: Jun 24, 2022

Do I need to seal cement board before tiling?

Asked By: Rotem Date created: Jun 23, 2022

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.

Answered By: leftaroundabout Date created: Jun 24, 2022

Do I need a vapor barrier behind cement board in shower?

Asked By: Seon Date created: Jun 18, 2022

Moisture barriers stop that water or vapor from getting any farther and potentially rotting your studs, the drywall or greenboard installed behind the enclosure. They are required beneath your shower pan and behind your shower walls.

Answered By: Ryan Wheale Date created: Jun 19, 2022

Can you put cement board over concrete?

Asked By: matiaslauriti Date created: Jun 08, 2022

Technically, cement board can be laid over a concrete slab as the base for a tile installation. ... A better solution is to prepare and resurface the concrete slab so that it can accept thin-set adhesive or a mortar base onto which to lay tile.

Answered By: Kelly Date created: Jun 10, 2022

Do you have to seal cement board before tiling?

Asked By: Mehran Ullah Date created: Jun 10, 2022

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.

Answered By: Mechanical snail Date created: Jun 13, 2022

Is concrete block waterproof?

Asked By: gabra Date created: Jun 09, 2022

Waterproofing Concrete Block Foundations. Concrete blocks and cinder blocks are much more permeable to water and water vapor than poured concrete. ... Block foundation walls will provide only a weak barrier against capillary water seepage and water vapor.

Answered By: zeytin Date created: Jun 11, 2022

Do I need to waterproof cement board in shower?

Asked By: Tommy Date created: Jun 16, 2022

Here's what the TCNA handbook has to say about the matter: “A waterproof membrane or vapor retarder membrane must be specified to prevent moisture intrusion and protect adjacent building materials.” ~B412 Bathtub or shower with prefabricated receptor. Cement board or Fiber-cement board.

Answered By: gbalduzzi Date created: Jun 19, 2022

How do you waterproof a flat concrete roof?

Asked By: WestCoastProjects Date created: Jun 18, 2022

Step 1 - Clean Your Roof. In order to successfully seal your roof, you first need to start with a clean surface. ... Step 2 - Carry Out Minor Repairs. ... Step 3 - Use Seam Tape. ... Step 4 - Coat With Primer. ... Step 5 - Spray on a Vapor Barrier.

Answered By: Srikar Appalaraju Date created: Jun 21, 2022

Do you need to seal a concrete floor before laying laminate?

Asked By: Nominal Animal Date created: Jun 17, 2022

You don't need to seal a concrete floor before installing laminate; however, to prevent moisture from the concrete floor from affecting your laminate, install a vapor barrier of polyethylene film. Install this barrier even if the concrete subfloor is covered by vinyl, linoleum, terrazzo or ceramic tile.

Answered By: Alexander Udalov Date created: Jun 20, 2022

What do you put on concrete floor before laminate?

Asked By: Andrii Naidenko Date created: Jun 15, 2022

Begin installation by laying a plastic vapour barrier (minimum 6 mm thick) or any other manufacturer-recommended barrier on the concrete subfloor to prevent moisture from reaching the laminate flooring. Use vinyl tape to secure the barrier and keep it from coming out.

Answered By: coroutineDispatcher Date created: Jun 17, 2022

Do you need plastic behind cement board?

Asked By: diEcho Date created: Jun 12, 2022

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).

Answered By: NullUserException Date created: Jun 12, 2022

Related Question Answers

jmite

Professor

Do you need a vapor barrier behind cement board?

You still need a vapor barrier with cement board, although in this case the barrier can go behind the board. Cement board is heavy enough and breathable enough to take the moisture without a problem. By having the vapor barrier behind the cement board you stop the moisture going further into the wall.

ale13

Professor

Do you need green board behind cement board?

Because cement board can be used either for floors or walls, the surface below the cement board will vary: ... 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.

Utshaw

Professor

Do you need to put a vapor barrier behind cement board?

You should NOT place a vapor barrier BEHIND the backer board. Where, pray tell, would any such collected vapor/water go? Answer:There's nowhere proper for such moisture to egress. The current best practice is to place waterproofing OVER the backetboard and just UNDER the tile.

Cory Kramer

Professor

What do you put behind cement board in shower?

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..

e.James

Professor

Do you put cement board under a shower pan?

Once the subfloor of proper thickness is properly installed then you can apply cement board directly to the subfloor material. ALL CEMENT BOARDS MUST be installed in a fresh bed of thinset. ... If you want the cement board under the shower tray then do so - doesn't matter.

Tarik Huber

Professional

What can I use instead of cement board?

Glass mat gypsum board is a better choice. Sheets of glass mat gypsum are made from water-resistant silicone-treated gypsum, reinforced on both sides by fiberglass mats. DensShield is one common brand. It is easier to cut than cement board, it is mold resistant, and it has a built-in moisture barrier.

Yoel

Professional

Can I pour concrete around cast iron pipe?

You could just add a couple inches of sand, enough to handle the vapor barrier and then cover the pipe with a couple layers of plastic or roofing material and place the concrete right over the pipe.

Ashley Mills

Professional

Can moisture come up through concrete slab?

The ground beneath nearly all concrete slabs is damp-in fact, it nearly always has a relative humidity of 100%. That means it is a continuous source of water vapor into the slab and the slab will never dry out-especially if you put a coating on the surface that restricts the movement of water vapor.

Bianca Balan

Professional

Can plaster walls be insulated?

If your historic house has original plaster walls, you should not blow insulation into the exterior walls. Old houses with plaster walls have no vapor barrier under the plaster to stop moist air from saturating the insulation. Instead, plaster walls are designed to allow the free exchange of air and moisture.

Ronak Shah

Professional

Can you finish cement board like drywall?

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.

Harsh Bhikadia

User

Can you glue stone veneer to cement board?

What can I put stone veneer on for an interior application? For interior applications, stone veneer can be installed over cement board, drywall, and all of the above.

Mr_Green

User

Can you put cement board over tile?

Cement board forms a durable, stable base for tile, and it has no organic materials (unlike drywall, greenboard, or plywood) so it is not prone to mold, rot, shrinkage, or decomposition due to moisture. Ceramic tile laid over cement board is one of the most durable floor or wall surfaces you can install.

abc123

User

Can you put cement over silicone?

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..

Niklas B.

User

Can you put solid hardwood flooring on concrete slab?

With dry concrete and the right subfloors and vapor retarders, solid hardwood floors can be installed on slabs that are either on-grade (at ground level) or above-grade (above ground level). ... Wood floors should not be subjected to very wet conditions.

Delan Azabani

User

How do you fill gap between cement board and tub?

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.

nickgryg

Guest

How do you install moisture barrier under concrete slab?

Most exterior slabs do not need a vapor barrier. ... In general, place the concrete slab directly on top of the vapor barrier, with the subbase below. ... The vapor barrier can be placed under the subbase, if the building is closed in when the dry subbase material is placed.More items...

yivi

Guest

Can you use 1/4 inch cement board walls?

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.

Anatolii Chub

Guest

Can you use cement board for shower walls?

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..

StuartLC

Guest

Do I need a vapor barrier between concrete and laminate flooring?

It is rolled out between the actual laminate flooring planks and the subfloor.

Very often, particularly in a below-grade installation on a concrete basement floor, a vapor barrier is recommended in addition to the underlayment.

That vapor barrier would go between the subfloor and the underlayment..

rodrigo-silveira

Guest

Do I need a vapor barrier between concrete and wood flooring?

Despite a successful moisture check and the presence of an underground moisture barrier, you still need additional protection from water vapor before laying a wood floor. Sheets of 6-mil thick polyethylene plastic, overlapped with seams taped, is one means of providing that moisture barrier.

Dávid Pásztor

Guest

Does cement board need to be sealed?

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.

Lukasz Wiktor

Guest

Should you seal concrete before laying laminate?

You don't need to seal a concrete floor before installing laminate; however, to prevent moisture from the concrete floor from affecting your laminate, install a vapor barrier of polyethylene film. Install this barrier even if the concrete subfloor is covered by vinyl, linoleum, terrazzo or ceramic tile.

Peter Boughton

Guest

Do I need cement board for kitchen backsplash?

But for a tile backsplash, if your wall is good and plumb, without any major ridges or problems, you don't always need to use a backer board, often you can just apply thinset to the walls and put your tiles in place.

Jonathan.

Guest

How do I stop moisture in my concrete floor?

Methods Used to Stop Moisture in Concrete FloorsLow-permeance Vapor Barrier or Retarder.

A Low-permeance vapor Barrier or retarder can effectively keep below-slab moisture from reaching the flooring system.

...

Allow Natural Drying of Concrete Slab.

...

Keep Excavation Free of Water..

Meno Hochschild

Guest

Is a vapor barrier necessary behind cement board?

Cement board is heavy enough and breathable enough to take the moisture without a problem. By having the vapor barrier behind the cement board you stop the moisture going further into the wall. ... You should NOT place a vapor barrier BEHIND the backer board.

jondavidjohn

Guest

Should I put plastic behind cement board?

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.

sophocles

Guest

Does cement board in shower need waterproofing?

“A waterproof membrane or vapor retarder membrane must be specified to prevent moisture intrusion and protect adjacent building materials.” ~B412 Bathtub or shower with prefabricated receptor. Cement board or Fiber-cement board. Ceramic Tile. ... Consult local building code for moisture barrier requirements.”

Aleks G

Guest

Can you put cement board on the floor?

Cement board is a type of underlayment that is now standard for most tile installations, but particularly for floor tile.

The primary benefit of cement board is that it doesn't break down or expand or warp if it gets wet.

This is a distinct advantage over plywood and drywall..

BCS

Guest

Do I need insulation under a concrete floor?

Creating an insulation layer and a vapor barrier between the concrete slab and the ground beneath it is the best practice in insulating basement floors.

The insulation barrier will help keep warm air in, and the vapor barrier will keep unwanted moisture out..

axiac

Guest

Do you have to put Thinset under cement board?

No Thinset underneath the backer board “The thinset goes ON TOP of the cement board to stick the tiles!” ... Cement board is a different product and it needs to be installed in its own way. Additionally, screws don't take the place of thinset either.

Giang Le

Guest

Should I put Thinset under cement board?

Embed the cement board in latex-modified thin-set mortar The main reason for using thin-set between the cement board and the subfloor isn't as much for bonding as it is for even, void-free cement board support throughout the floor. ... Then spread thinset mortar with the flat side of a 1/4-in.

Josh Kelley

Guest

What do you put on seams of cement board?

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.

Lekensteyn

Guest

What is the best insulation for under a concrete slab?

Applying a bead of polystyrene-compatible caulk or mastic to the top of the insulation board minimizes water infiltration behind it. For under-slab applications, the rigid foam insulation typically should be installed over a gravel base, with a poly vapor diffusion retarder between the gravel and insulation.

Peter Boughton

Guest

Is cement board the same thickness as drywall?

Whereas drywall comes in 4-by-8 sheets, cement board comes in 3-by-5 sheets. ... The smaller dimensions of cement board make the installation of it on large walls more difficult, but cement board panels fit vertically in 3-foot wide showers, or horizontally behind a standard 5-foot bathtub.

zed_0xff

Guest

Is Durock cement board waterproof?

Hence the question “Is cement board waterproof?” Well, here's what some manufacturers have to say about waterproofing: PermaBase (National Gypsum): PermaBase PLus is not a water barrier. ... Durock (USG): “If waterproofing is desired, use USG Durock™ Tile Membrane or USG Durock™ Brand Waterproofing Membrane.”

timbo

Guest

Should you waterproof 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..

YPCrumble

Guest

What is the purpose of a vapor barrier under concrete slab?

The use of a vapor barrier (more accurately termed a vapor retarder), having a water vapor permeance of less than 0.3 perm is frequently used to retard the flow of moisture through the slab. These vapor retarders are typically polyethylene or polyolefin sheeting materials.

Aaronaught

Guest

How do you insulate lath and plaster walls?

Treat Your Gutted Walls Like New Construction When you have gutted your walls, install fiberglass batting, foam insulation or dense-pack cellulose insulation from the inside. Place a 4-mil plastic sheeting vapor barrier over all three of these types of insulations.

Lucio Paiva

Guest

Is concrete a Vapour barrier?

Actually, no. Air barriers need to be continuous and free from holes, but vapor barriers do not need to be. Lots of vapor moves by air movement, not a heck of a lot of vapor moves by vapor diffusion. The concrete slab is the air barrier, and the ripped and torn and punctured polyethylene sheet is the vapor barrier.

Kit

Guest

Do you need a vapor barrier under concrete driveway?

The application of vapor barrier in exterior concrete is unnecessary due to the fact that water penetration does not matter. Any slab on grade that is enclosed and on the interior of a building should have a vapor barrier installed prior to pouring concrete, especially if flooring will be applied.

synthesizerpatel

Guest

Do you put plastic under concrete slab?

In California they place sand between slabs and plastic vapor barriers—in Florida they don't. Almost everywhere (except “California”) that slabs are placed on the ground—a plastic sheet—a vapor barrier—is located directly under the concrete slab and on top of the ground (Photograph 1).

davidxxx

Guest

Can you caulk cement board in shower?

In the event the caulk seal between the bottom row of tile and the tub/shower fails, water can get behind the tile. If the backer board is touching this ledge, it will readily soak up this water like a sponge. ... Then, before installing the tile, apply a bead of pure silicone caulk between the backer board and the ledge.

Even Mien

Guest

Do you have to glue down cement board?

You cannot put a cement backer board over that. You need to put a layer or plywood, minimum 5/8 IIRC, over those boards, then mortar the backer to the plywood. Those 1x8 boards won't give a solid foundation and will flex. Over time, that will cause tile to pop loose or crack.

Jesse Carter

Guest

Where do you put cement board in a bathroom?

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.

harpo

Guest

Do you have to put cement board under tile?

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.

Eli

Guest

Can I just screw down cement board?

Put thinset beneath your backerboard. And put your dog out. Once you have the area fully covered with thinset you can lay your backerboards into the bed of thinset and screw it down. DO NOT use drywall screws!

Acorn

Guest

Is concrete slab waterproof?

Concrete slabs are not impervious to water. In fact, given the right environmental conditions, the floor slab can transmit gallons of water into the living space as vapor, and in extreme cases, actually show ponding water. ... The pre-construction solution is to use an underslab vapor barrier.