Installing concrete board in bathroom

It sounds like you want the shower to be curbless and even with the existing floor? Check out my post on waterproofing systems but if you want to build a curbless shower in that space then I recommend the Wedi Ligno shower system.

Should I remove the Luan or can I use thin set on top of the luan? Also if it is OK to use the Luan, what spacing should the hold down screws be? Thanks for your time. Thanks for your time dwm. My wife has MS. I bought an Oakley ProLine linear drain. The main tiled area in the bathroom has been leveled and has a heated floor. I plan on securing 2x6s with construction adhesive and screws to the existing floor joists to get the slope I need.

You definitely want to remove the Luan and thinset and fasten the Hardibacker to the subfloor directly. Probably under at the tile layer also. Maybe a modified procedure, like set the cement board with a trowel to give slightly thicker thunder, then take a measurement and adjust the thinset thickness for the tile to get a match with existing tile? There is no mortar between the backer boards and subfloor it was still brutal to tear up.

The old tiles extended underneath the edge of the tub which is slightly flexible vinyl? If I do that, what should I do to support the edge? Or would you recommend that I extend the tiles underneath like the old floor was? You can always flat trowel the back of the tile or hold your trowel at a straighter angle. Or mix your mortar stiffer.

I have a question. I want to apply a tile to the bottom of a wood post which is outdoors. Will it work if I install some cement board first the size of the tile I want to use?

Will this hold up to the moisture? Thank you so much!!!! Hi I want to use large porcelain tiles over my hardwood floors in my kitchen, dining-room and living-room because we have lost of traffic and a dog.

I was wondering in the installer used hardibacker board over the entire floors and screwed them down, would that be sufficient enough to use thinset and then use the porcelain over it? Thank you for your comment.

It needs to come out and then you can build over the subfloor. I am redoing a bathroom and installing cement board for the first time. Everything looks great, however all of the seams are slightly raised due to taping. Do I need to sand these down a bit or is the difference too small to make a difference? Thanks for the reply. This is a great site for DIYers. Hi, Is it recommended to put a wedi board or schulter membrane in the front door vestibule on cement floors.

The current tiles are all cracked. Will the membrane help reduce the tile from cracking. There are a lot of reasons that tiles and grout joints can crack. They may not be installed with proper exterior mortars.

Maybe there is no room for movement. They are solid, but not super tight together due to the age of the house. Will just screwing the cement board down make the tiles crack? Should I use some thin set on each individual subfloor plank? Then you can use a thin membrane over that if you want. Anything short of those two options is taking a risk. I am going to pour a concrete counter top in place over plywood. Can I install backer board on top of the plywood before pouring the concrete?

After applying the thinset and laying the cement board down do I need to stay off it till it sets? You want to get on it right away to get the fasteners installed while the mortar is still wet. Once the fasteners are installed you can continue to walk on it all you want. Does it need to dry for a specific amount of time before tiling over it?

You can put it on right away if you want. Good question! Ok, so we had square feet of porcelain tile installed through the first floor of our home. The tile runs from our utility room through the kitchen, hall, bathroom and foyer.

The installers tore out the old tile which was installed over plywood. They were supposed to rip out the plywood, put down Hardie board and then tile. But they said the plywood was glued down to the subfloor and thought tearing it up would cause damage to the subfloor.

So instead they left the plywood. And they did use thinset between plywood and hardie back and also between hardie back and tile. I have two questions… is the way this was installed ok? Also is the weight of this ok? I know that might sound a little crazy, but I always get nervous about the structure of homes.

Can my subfloor handle the weight of plywood, hardie back and tile on top of it? Uh oh… I spoke too soon.

In the last question I asked I explained how the floors are higher than they used to be. These are metal doors. But even if they could that would cause a problem with the weather stripping being able to meet the threshold. Any suggestions on how to fix this? My guess is that there is a way and you can raise the height of the threshold. Maybe someone in the community has a better answer? Hi, I removed the carpet of my master bedroom and cure the cracks on the floor with two layers of RedGard.

I was going to do it with siroco over the base floor. But you said that it is not a good idea. What is the best way to do it then? I think the best way would be with a self-leveling cement. I want to eliminate the issue where moisture destroys the particle board that normally butts up against the entry door.

The height will be different but I can add a thin luan sheet in-between the 2 to make up the difference. Do I need to use any thin set morter for the hardi if I intend to have click vinyl plank installed as the finished layer on top? I would use the cement special screws to attach the hardi to the plywood. Thanks Ron.

The other thing is that a little mortar underneath may make the heights work out perfectly. Please explain WHY is thinset necessary? Why are screws alone not adequate? What is it about backer board that necessitates thinset as an additional agent in its installation? I am not asking to be a jerk, it just does not make sense to me.

Seven years ago I did a large format tile project sq ft using screws only, as of today it still going strong, no cracks, no anything? What benefit or capability does thinset add that without it the installation is compromised? It takes away movement. Screws or nails hold the backer down and thinset holds it up.

Once dry, it takes away any gaps and any further movement in the backer board. I do not trust any that the thinset will hold the boards down long term. I am tiling over existing tile, using mapei eco prom grip. Should I use self leveling cement instead. If so, which brand do you recommend? Foam board panels, like Wedi board or GoBoard, come in a variety of sizes and have a procedure for installing over cement.

Additionally, self-leveling underlayment works fine and would give a flat floor, if done correctly. The easiest solution, as long as the heights will match up, would be to use an uncoupling membrane like Ditra or Ditra XL. My kitchen tiles became loose one by one. I lift the wonder-board and I see a straight crack. What could be the reason? So, that tells me that there is no mortar underneath the cement board which could be the cause of your loose tile issue. If you want to use tap cons and install them per the fastener schedule then maybe that will work.

Great forum thanks a lot. I am getting ready to install tile in a small upstairs bathroom. I first poured self leveling concrete to make up for a substantial slope, I then cut Hardi backer which I will install with thin set underneath and finally screw down the Hardi backer through the self leveling concrete and into the plywood sub floor.

Does this seem like an ok idea or do I need to scrap the Hardi backer for a different product over the floor leveler? Thanks a lot, Jon.

First thing, is I would check if you installed the correct leveler. There are only certain levelers that are approved for going over wood substrates and one of those types would need to be installed.

Alternatively, some levelers require metal lath to be installed over a wood subfloor prior to installing the leveler. If you wanted to install cement board then that should have been installed first thing and directly over the wood subfloor. I am in the process of installing a new ceramic tile floor over hydronic viega radiant heat. I will use the viega climate panel, which the pex tubing snaps into. The viega installation instructions say to glue and screw the backer hardie board down.

Your suggestion is to use thinset and screws. What method should be used and if it is glue, what type? Or if thinset, what type issued over the pex tubing? Thanks for any information.

Can you put thinset mortar on OSB subfloor? This is not advantech OSB just the Lowes cheap stuff. It depends on what you are installing. If you are installing cement board or an uncoupling membrane then, yes, you would thinset those down and sometimes to OSB. What is it that you want to stick to the OSB with the thinset? Appreciate this page.

I have 1 inch thick by 4 inch wide pine boards, with no subfloor underneath. The boards fasten right to the beams underneath, thus removing them is not really an option I believe. They are solid as only about 10 years old, but not tongue and groove so not super tight in all spots.

I have a feeling I need to use plywood above before I put down thinset and backer board but want to confirm that. I understand that the backer board does not add structural strength, but do I really need that if the floor itself is strong? My home has OSB as a subfloor like alot of homes now. Is it safe to say that I can treat it like a plywood subfloor and place mortar, cement board, mortar then tile or is it not even worth doing with having OSB?

At least not yet. The other advantage of this is that it keeps the overall height of the floor down. Cement board is a great way of going over OSB and the way that you outlined should work perfectly.

Additionally, it helps if you can scrape, or sand, the surface to promote adhesion. If anything happens then the particle board will swell and ruin the tile. You can rent a toe kick saw if you need to get under the cabinets. Link to instagram video about removing vinyl subfloor. You can also install backer board, like you mentioned, but then the floor height is going to be a lot higher than it currently is and you could have issues with door heights, etc.

Thank you for a great forum. I am replacing 20 year old 8X8 ceramic tiles in our 80 sqft kitchen installed on gypsum. When I removed the old tiles and gypsum, OSB board revealed random spots of dried mold especially under the refrigerator. Apparently the refrigerator had small leaks over the years but the compressor heat evaporated the water while causing minor mold therefore we did not have any extensive smell of the mold.

Since I had a hip fracture 2 years ago, doing floor work was extremely difficult and expensive especially thin-setting multiple times between layers of the underlayments.

I experimented laying DITRA first under the sink cabinet 4 sqft area and realized that 80 sqft will be a huge pain. However, my enthusiasm has been curbed when I read Hardibacker installation instructions and your recommendations that I still need to have thinset under the cement board. That means I am back to where I am with thinset mess and pain and more expense.

Second question is, Hardibacker is not waterproof unless I use Hardibacker Hydrodefense for Walls. Can I use Hardibacker Hydrodefense for floors? For me waterproofing and protecting 20 year old OSB from mold is more important. Really appreciate your advice. It sounds like you need to come up 1 inch with the underlayment. I think the best way to go would be to add plywood over the floor as it is right now.

You would have to check with the manufacturer to see if mortar underneath Hardibacker is necessary. I know Hardibacker wants mortar underneath but they are also assuming that you will be installing tile with a mortar adhesive. You can waterproof over the Hardibacker on a floor if you want.

Also, on one side of the tub against the wall they installed green board. At the back of the tub there is the Hardibacker where it joins into the open shower. I had thought to put Redguard over that section which will not receive a lot of water.

Am I cool? Or should I demand it be cut to the height of the tile installation and hardibacker installed. The shower is separate from the tub. Either thickness of Hardibacker works just fine over a floor.

IUsing thinset under cement board depends on your subfloor. Over plywood I agree.. They spray a wax waterproofing on the floor.

Thinset will not bond to it. Most new houses have advantic in them. You have to sand the whole floor down.. It usually dry before that and you can tell by the color change of the mortar.

We put the cement board smooth side out, because for reason reason I had it in my head that thin-set was a mastic and not mortar. Am I doomed if I use thin-set on the smooth side? I have a laundry room that had a laminate sheet flooring in it. I removed the laminate to find they had put down 3 layers of it glued in various places.

It all looks to be the same so I guess it was done at the same time. I finally got this up and find the glue is not coming up. Can I use a cement board to give me a clean level surface to lay my tile on? However, if you have a wood subfloor then you may not be down as far as you need to be. Typically, the flooring is over an underlayment that is on top of the subfloor.

That underlayment should come out as well. It is on a concrete floor. As I said I am down to just the remaining glue. It is hard and not coming up. I talked with a contractor and he said we could do the backer board or a leveling compound. Not sure what to do as I now have a cement floor with the glue remanence on it.

You could use a foam board like Wedi or a leveling compound. The best way to get rid of the glue is to grind it off with an electric grinder and a diamond cup wheel.

Alternatively, you could prime over it with a product like Mapei Eco Prim Grip and then use a leveler or even adhere tile directly to that. I hope I have enough information to make an answer possible. We are renovating the mudroom and lav of our home. I have a contractor, but was expecting to lay tile ourselves. The contractor has removed the previous tiles, which have been cracking. If I understand correctly, they had been set over vinyl flooring with no cement board.

In general, though, I trust him. Do I need to find another flooring material? Should I limit myself to significantly smaller, or even mosaic, tiles? They are trying to tell you the best way to install them. What about door swings? Bluestone is very thick and heavy, probably has some variance in the thickness of the product, and is going to be difficult to cut and install.

If you do decide to move forward with the bluestone installation, I would recommend getting a professional installer. Hi there! I have removed all the vinyl flooring in the bathroom but there is quite a bit of old black adhesive which has been almost impossible to remove.

Is that something I can leave and cover with thinset or do I need to use a self leveling product? I have a bathroom floor to tile. I am told that the 5mm underlayment is luan plywood. The thin set bags I have seen at the big box store say not to use on luan plywood. Do I need to replace the luan with an exterior plywood or is there a thinset available for use on luan? Unfortunately, the black adhesive probably contains asbestos so caution needs to be taken when this is encountered.

These can be painted over the cutback adhesive. Then you can proceed with Hardibacker or whatever underlayment that you are going to use on your floor. Unfortunately, the luan plywood needs to be removed and replaced with an exterior plywood with a face grade of ACX. Can I put cabinets over cement board right away or do I have to let it dry just want my sink hooked up as soon as possible.

I was considering using DryPly coated plywood under my HardiBoard installation. Am I correct in assuming this is OK as the adhesion of the thinsett to the plywood is not necessary? Treated lumber has high moisture content and warps when it dries out. This product looks like it falls into this category.

What is recommended is exterior grade ACX plywood. Hello, My husband and I just installed hardiebacker last night over two layers of super thick plywood. We used thinset under the boards, the proper screws, meshtaped the seams, and all boards were cut to meet properly.

Use only cement board screws and alkali-resistant cement board joint tape. Standard screws and drywall joint tape will corrode or deteriorate from contact with cement board.

Continue installing sheets to cover the entire area. Mix fresh mortar only as it's needed to prevent it from drying before you can use it up. Apply cement board joint tape to all of the joints between sheets, adhering the tape with its self-adhesive backing. Mix more thin-set mortar and, using a drywall knife, cover the taped joints with a thin layer, much as you would do when mudding drywall joints. Tool the mortar with the knife so the tape is covered and the joints are flat and smooth.

Allow the mortar to cure completely, following the manufacturer's recommended drying time. Installing cement board on countertops is very similar to the process used on floors, but countertops usually need an additional strip of cement board along the exposed edge of the countertop. This creates the built-up edge for securing bull-nose or other forms of edge tile.

Cement board on walls also uses the same techniques, but in this case, there is no layer of mortar behind the cement board as it is screwed directly into the wall studs. Consult the cement board manufacturer for recommendations on using a moisture barrier between the board and the wall studs.

This may be thick plastic sheeting or another type of water-resistant membrane. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights.

Measure content performance. Develop and improve products. List of Partners vendors. Project Overview. Featured Video. Materials Cement board sheets Thinset mortar Cement board screws Self-adhesive cement board mesh joint tape. Installing Cement Board on Floors Plan the Installation Make a rough plan for the cement board sheet layout, based on the area to be covered and the size of the cement board sheets.