Best answer
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).
Do I need a vapor barrier behind cement board in shower?
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.
Do you need to waterproof cement board before tiling?
So, if you're looking for durability and strength, concrete backer-board will probably be your choice. First, you should provide a waterproof/resistant membrane against the wood studs before installing the concrete backer-board to protect the wood studs from moisture absorbed through the backer-board.
Do you need to tape cement board before tiling?
2 Answers. 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. 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.
Do you need to prime cement board before tiling?
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.
How do you anchor a plaster wall?
Lath and plaster walls can't accept typical plastic anchors. Toggle or molly bolts are required. Be sure to use ones that are long enough to get behind the plaster and lath. Drilling a hole with a masonry bit will be required, more below on installing toggle and molly bolts.
Do you have to use 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.
Do you need to waterproof cement board in a shower?
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.
Do I need to waterproof cement board in shower?
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.
How do you run wires on a concrete wall?
You need some plastic anchors, you can see some here. You can buy mortar screws that come with plastic anchors. Simply drill a hole into the concrete with a a concrete bit and then glue the plastic anchor into the hole then drill the screw into the plastic anchor. You can get ones with a cable brackets.
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.
Related Question Answers

usr1234567
ProfessorDo 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.

Hakalardeli
ProfessorDo 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.

Nyambaa
ProfessorWhat 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..

David M
ProfessorDo 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.

Daniel J.G.
ProfessorCan you cement over plastic pipes?
plastic pipe will also react against cement. all plastic pipe web sites will tell you it must be insulated." The plastic pipe will not react against cement.

abarnert
ProfessionalHow 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.

Sergey Bushmanov
ProfessionalCan you use cement board as a subfloor instead of plywood?
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.

Colleen
ProfessionalCan you use plastic cement on resin?
Just do NOT use 'plastic cement' or "liquid cement." This is designed for plastic models, not resin. It works by partially dissolving the plastic so the parts will fuse together. Resin does not dissolve so 'plastic cement' will have no effect on it.

Sarfraz
ProfessionalDo I need a shower pan liner on concrete floor?
JRC3 Member.
It will need to be lined or it will wick into the slab and studding.
The liner also makes the walls around the pan water-tight, that's why the liner normally goes up at least 3" above the pan behind the tile and backer material.
Moisture gets behind the wall tile and is eventually caught by the liner..

rakib_
ProfessionalDo I need cement board for stone veneer?
Natural stone veneer is heavy and should not be installed over drywall; cement backerboard or masonry applications are recommended.

Waldi
UserDo I need to prime cement board before tiling?
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.

wahab memon
UserDo you have to replace cement board under tile?
Undamaged cement backer board does not need to be replaced.
...
It is difficult to remove tile from a cement backer board, and even more difficult to avoid damaging the board in the process.
Since backer board is relatively inexpensive, it's not normally worth the time and labor it would take to remove the tile to save it..

leonbloy
UserDo you leave a gap between cement board?
Stagger all HardieBacker cement board joints. Do not align with subfloor joints. Never allow all four corners of boards to meet at one point. We recommend an 1/8 in gap between board edges.

Pierre D
UserDo you need a shower pan liner on concrete floor?
JRC3 Member. It will need to be lined or it will wick into the slab and studding. The liner also makes the walls around the pan water-tight, that's why the liner normally goes up at least 3" above the pan behind the tile and backer material.

Arseniy-II
UserDo you need anchors for plaster walls?
Lath and plaster walls can't accept typical plastic anchors.
Toggle or molly bolts are required.
Be sure to use ones that are long enough to get behind the plaster and lath.
Drilling a hole with a masonry bit will be required, more below on installing toggle and molly bolts.

Matthew Groves
GuestDo you need 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). ... In such wet areas, never install cement board directly over drywall or green board.

Shobhith Yadav
GuestDo you need 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..

Ace
GuestDo you need vapor barrier behind cement board?
If it's a cement board, you need a vapor barrier, because cement retains moisture, which means the wood next to it is always damp.

unutbu
GuestDoes cement backer board burn?
The backer board will burn out eventually. You also need to build an insulated heat riser for best performance. A bell around/over the heat riser cannot be cement board as the heat in parts of that will be much too intense.

Vadzim
GuestDoes 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.

Azat Ibrakov
GuestDoes Loctite Power Grab work on cement board?
It will bond to drywall, plaster, vinyl cove base, polystyrene, polyurethane foam covings, PVC (rigid plastic), stainless steel, glass, wood, plywood, stone, brick, concrete, chip board, ceramics, foam board, cork, and carpet.

sberry
GuestDoes Tamiya plastic cement work on resin?
The Hospitalar is resin.
Plastic cement won't work.
You'll need super glue or epoxy..

rightfold
GuestCan I use cement board for shower floor?
Do not use cement board on its own. Your shower will leak and you will be tearing it out within a year.

sawa
GuestCan you use plastic anchors in plaster walls?
Plastic wall anchors don't work with lath and plaster walls. Instead, use plaster anchors made of metal like a molly bolt or a toggle bolt. Be sure to use one that's long enough to get behind the plaster and lath. When drilling into plaster, you'll need to use a masonry bit.

ch271828n
GuestHow do you repair concrete pool tile?
Remove all loose tiles. Remove all loose cement from behind the tiles. Use hydraulic cement to fix cracks & holes. Let dry for 24 hours.

sathishk2030
GuestWhy is my cement cracking?
When concrete is still in its plastic state (before hardening), it is full of water. When that water eventually leaves the slab, it leaves behind large voids between the solid particles. These empty spaces make the concrete weaker and more prone to cracking.

Akshay Vijay Jain
GuestDo 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.

erb
GuestDo I need cement board for tile floor?
If you're working over a wood subfloor, cement board is the right choice for your tile base. No matter what you're told at a home center, it's not a good idea to install tile directly over plywood, especially in a damp area like a bathroom.

Frode F.
GuestDo you put cement board under bathtub?
You don't need any cement board under the tub. It is far more important to have a sturdy layer of ply under the tub.

Igor
GuestIs 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.

Michał Miszczyszyn
GuestShould 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.

Jimmy
GuestCan I reuse cement backer board?
Undamaged cement backer board does not need to be replaced. If tile has not been attached directly to the backer board, and it has not been dented or punctured, it can be reused without any special preparation.

peirix
GuestCan you concrete over plastic pipes?
plastic pipe will also react against cement. all plastic pipe web sites will tell you it must be insulated." The plastic pipe will not react against cement.

Hrishikesh Kadam
GuestDo 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).

NishanW
GuestHow do you fix cement board in a shower?
Linda CottinStep 1: For holes larger than 1/2-inch in diameter, use a carton knife or carbide-tipped tool to cut a V-shaped groove behind the edges of hole. ... Step 2: Use a clean, damp sponge to wipe down the area to be patched.Step 3: Mix up a small amount of thin-set mortar following the manufacturer's instructions.More items...•

Diego Torres Milano
GuestShould I put cement board under tub?
You don't need any cement board under the tub. It is far more important to have a sturdy layer of ply under the tub.

simbabque
GuestShould you put 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.

Jannie Theunissen
GuestIs 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.

matt wilkie
GuestWhat do you use to seal cement board when tiling?
The thin-set is a cement-based powder that you mix with water or latex additive to form a thick paste, which is used to seal the seams in the board and can also be used to set the tile. Finally, you'll need an 8 x 12-ft. piece of 4-mil plastic sheeting and some straight 2x4s.

avdeluca
GuestDo you need to plaster over plaster board?
If an existing plaster wall is in good condition – smooth and without major cracks or chips – then you probably don't need to have it skimmed. If you've attached plasterboard, or drylining you have the choice of either painting or decorating straight onto the board, or finishing with a layer of skim plaster.

Mark Rogers
GuestWhy do you cover concrete with plastic?
Covering the curing concrete with plastic keeps it cleaner, but there is a more important purpose behind this practice.
...
To prevent cracks, plastic is placed over the curing concrete to trap the water inside and regulate its temperature, ensuring gradual curing..

Lars Kotthoff
GuestCan 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.

Aziz Alto
GuestCan you make a shower pan with cement board?
Do not use cement board on its own.
Your shower will leak and you will be tearing it out within a year..

Brad Gilbert
GuestDo 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.

Arvind Kumar Avinash
GuestDo you need a shower liner on concrete floor?
JRC3 Member. It will need to be lined or it will wick into the slab and studding. The liner also makes the walls around the pan water-tight, that's why the liner normally goes up at least 3" above the pan behind the tile and backer material. Moisture gets behind the wall tile and is eventually caught by the liner.

Sam Chen
GuestWhere 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.

FlyingTeller
GuestWhat kind of paint do you use on cement board?
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.

Max Makhrov
GuestDo I need cement board under floor tile?
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.

HARSH MITTAL
GuestDo you need to waterproof cement board in shower?
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.

Malt
GuestDo you need to use 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.