I’m tiling an upstairs bathroom. The floor is plywood, and I’m hesitant about using Hardie backer board because the height of the floor will be too high. Can you tile directly to plywood with thinset? —Chris
While you can lay tile directly over a concrete slab using thin-set adhesive, don’t make the mistake of applying tile directly to a plywood subfloor. No matter how firm the subfloor; the plywood will expand and contract at a different rate as the tile, causing cracks to develop in the grout lines or tiles over time.
On a plywood subfloor, you need either a layer of cement backer board or an underlayment membrane, like Custom Building Products’ Wonderboard and RedGard, between the subfloor and tile for the thin-set adhesive to achieve a good bond.
While I prefer using 1/2” cement backer board over a plywood subfloor, you may be able to get by with 1/4” backer board instead. Even if you use a waterproof underlayment membrane, the floor will still be either 1/4″ or 1/2” higher than the subfloor, plus the thickness of the tile and adhesive.
When applying cement backer board over a plywood subfloor, be sure to adhere the two surfaces together with thin-set adhesive; and screw the cement backer board down with special screws that countersink into the backer board, such as Backer-On screws available at The Home Depot.
Good luck with your project,
I’ve discovered an area of rot in my plywood subfloor between my bath tub and toilet. To my surprise, the marble tiles were laid directly on top of this plywood without cementboard (probably because the toilet drain calls for a rear flush model, and cementboard would have disrupted where the toilet and drain met).
If I had the time to be meticulous, I’d open pandora’s box and do the whole thing right- But I dont.
My question is whether or not I can replace the rotted subfloor with a thinner plywood and then cementboard to meet the current subfloor height, or am I in over my head with this fix?
YES, AND NO !. Yes for a quick solution, but I recommend you find the correct or approx thickness of the plywood to replace this area. ( if not use self-leveling liquid cement to reach the same level to rest of the old plywood).
I had carpet down on a concrete slab floor and I was wanting to put tile down but I was wanting to find a cheap and easy way to put the tile down quickly.
I will be installing tile on my brothers new home. This is the first time i will be using the underlayment rather than the backerboard and was wondering if I should be putting down like an 1/8 sheet of plywood just in case they plan on removing this floor in the future instead of bonding it right to the permanent subfloor? What is your suggestions?
I just removed the hideous pink tile floor from my master bath. It was layed directly onto the plywood subfloor – 25 years ago. *Zero* cracked tiles, *zero* cracks in the grout. It was in perfect condition and that bathroom was used daily for 25 years.
So why are people recommending backer board or some other membrane?
I too, just removed original tile from a mid 70’s house that was directly on plywood subfloor….no crack and grout was perfect, however, they did not use thinset to adhere the tile, looked like a standard construction adhesive. Any thoughts?
I have laid tile directly over plywood and it will work in small areas but when you have big areas of tile I would use some kind of backer board
I am tiling bathroom floor that is roughly 60inches by 60 inches. Is backer board really necessary?
I’m not a pro but I’ve done about six different bathroom and kitchen floors as a fussy DIY-er. I’ve had good results with tile set in thin set on plywood as long as I get two things taken care of.
One – the subfloor needs to be stiff and solid. When in doubt add blocking in the joists (if you can get at them) and more screws in the subfloor to make sure.
Two – paint the plywood with some waterproofing / crack isolation membrane. It’s not necessary to make it fully waterproof just resistant enough so that moisture that gets through the grout joints mostly dries out back through the grout instead of through the wood.
My oldest floor is 15 yrs old and still looks great. Unless the floor gets really wet on a daily basis this should last indefinitely.
We have our large kitchen and hallway that was originally covered by 12 X 12 ceramic tiles on top of 3/8th inch plywood. Thin set was used instead of glue or adhesive. the floor tiles became loose, cracked and ugly looking over about 2 decades of use. Now the entire flooring of ceramic tiles needs to be torn out and replaced. we are thinking about having the 3/8th inch plywood torn out and replaced by 1/4 inch concrete board before the new tiles are installed.
Hey it is generally not a good idea to put tile directly onto your subfloor… Because most old homes only use 1/2 plywood or OSB. It is a good idea to put half inch plywood underlay to strengthen the floor before using modified thin set to put the tile directly on wood. If the subfloor is 5/8 or 3/4 you can probably apply tile directly to it with no problem.
Hi. We are redoing 230 square feet of tile in our front hallway. We are using 12×24″ tile. Should we use plywood and cement board or can we just use plywood for the subfloor? I know the subfloor must be really sturdy but because of the size of the tile I’m worried that overtime they may break? If we do use cement board and plywood I’m guessing we’ll have to use a thinset in between the two and then screw the cement board with a countersink. Can you please provide advice? Thanks!
I am getting ready to tile (ceramic 12″x 12″ tiles) on a wood floor using backer board. My question is: how does putting a pattern in the design affect the strength/durability of the finished floor? Is there a pro or con in adding different size tiles?
i removed 1/4 inch tile it was cemented to plywood. can i now use 1/2 tile or will it no be level by doorway to the adjacent floor? HELP
Hi, can one lay ceramic tiles over Parquet flooring, and if so, what preparation is required to do?
The tile industry has changed so much. I did it for 30 years over fir plywood. I still get calls for more work after being out of it for 10 years because my work held up. The nice thing about tiling over plywood is that, should you drop something and break a tile, you can remove it without disturbing the surrounding tiles. Try that with tile over cement board and see what happens. Adhering the cement board to plywood only works if the plywood is re-scuffed or sanded first with a 20 grit disc sandpaper and you use a minimum 3/8″ trowel for the thinset. To me, they ruined the industry with all the “latest and greatest” fad products. Glad I got out just when all of these new products came in. They suck to work with and common sense was never a factor in their designs.
I’m gonna put ceramic tile on a coffee table, I put 1/4 plywood on top of the table then putting the ceramic tile on top of that, so it should be ok
I live in a mobile home and it has carpet and would like to remove and put tile down. Can you use hardy board for a sub floor. When I walk a cross the floor in some areas the floor make noise. Have not done any thing yet . Going to leave some carpet what need to be done between the carpet and the tile. Thank you
The main reason for the cement underlayment is to have something for the tile to adhere to since will will not bond to wood. With that said, if there is no need to raise the area being redone in order to match up with an elevated surface in another part of the home, 1/4″ cement board is the best option. I prefer to use Hardiebacker Board for my floor projects because it is has the highest compressive and flexural strengths of any cement board in comparison to it’s weight and they offer 3’x5′ options as well as 4’x8′ options. I really like the 4’x8’x1/4″ option because I can knock out bigger square footage projects much faster and with less seams. I go right off TCNA guidelines.
1: Trowel out bed of unmodified thinset over wooden subfloor.
2: Place Hardiebacker in staggered pattern so no four corners meet.
3: Fasten Hardiebacker 1/4″ board with corrosion resistant screws or galvanized roofing nails 8 inches apart.
4: Tape joints with alkali resistant cement board tape. Apply thinset over tape and joints.
5: Ready for tile.
Please do not tile directly over plywood. A contractor did that in my kitchen some years ago, and resulted in very severe cracking of the tile and grout. It looks horrible. Don’t do it. Better to have it a little higher than deal with that kind of mess.
This information is completely wrong. Unfortunately the opinion of one person with a blog or website becomes gospel to all of those reading this. Do your homework before making these comments.
Tile can be installed over a plywood substrate, and it is actually a fantastic way to make sure you don’t have deflection in your floor. Try laying tile over 1/2″ Durock or Hardie and see what happens when the joists are 19.2″ or 24″ on center. Hope you didn’t like your beautiful new tile floor! I have gone behind numerous tile setters to remedy their work when they thought (as many of the others that are commenting here) that using thinset under 1/2″ Durock (over 3/4″ OSB) provided a sturdy substrate. Wrong.
There are tile companies that actually use 3/4″ exterior rated plywood as their standard substrate with a quality modified thinset. If you want to know why- it’s because it pretty much doesn’t matter what the subfloor is under that plywood. It ALWAYS works. You can have 5/8 OSB and 19.2″ OC joists and it still works. The obvious drawback is that the height of the floor gets to be pretty high at times and you have to watch the height of exterior doors, etc.
Consult professionals with these questions. These blanket statements becoming gospel are ridiculous and they happen all too often.
contractor laid tile on plywood floor board how can i fix. grout is cracking and tile loose. must i take up the whole floor
I am currently pulling up ceramic tile that I foolishly applied over plywood two years ago. DON’T DO IT! Use a Hardie board/cement backer no mater what the time/labor/cost/floor height. My shortcut really cost me.
I have one room in new construction where I want to lay CARPET tiles. The house is build tongue-in-groove OSB floorboards and thats it. No other substrate of any kind on top of that.
I’m afraid of applying the carpet glue directly to that one-and-only layer of flooring. If I ever need to take up the carpet in favor of some other kind of flooring (or even different carpet) that glue is gonna be a next to impossible to remove.
Like the ceramic tile conversations, I’m assuming that adding some sort of substrate first is in order? Even if it were particle board I’d surely think something would be advisable rather than risk having to tear up subfloor someday. Suggestions anyone?
Nooooooo! I worked for a friend as a helper. He has 30 years experience. We would have tile jobs sometimes over 10,000 sq.ft. in homes that cost one 1 million dollars. We’d do backslashes, floors, walls, etc. We would also do remodels. Yeah sure I pulled up tile off wood subfoors that looked fine. In fact the majority of them were ok. I’ve also seen some bad damage from tile on wood. I’ve never had a problem repairing broken tile on cement board. Why take the chance? Do it right the first time.
Uh oh! My contractor just finished laying 122sf if porcelain floors directly over plywood in my kitchen. When I had asked him if he needed me to purchase backer board. He said no, that he could lay it directly over the.subfloor. I felt this wasn’t right which led me to here, but i suppose it’s too late now. Did I create a bigger problem for myself?? He only charged me $500 for the labor.
I had tile installed in 2 upstairs bathrooms and they did not put anything on top of the plywood (1 of them actually jumped up and down on the floor and made the determination it was “fine”). Needless to say, the tile has cracked and the grout lines have cracked for the 2nd time (this was only 4 months ago and he’s already been back out here 1 time and will be coming back out again). He is now looking at a “flexible grout” but I don’t think it will flex enough to last any length of time without removing all the existing tile and installing something on top of the plywood. Does anyone know of flexible grout will flex enough to last on a 2nd floor without anything on top of the plywood?
I have luan over the top of my 5’X5′ bathroom plywood floor. If I apply a layer of Redgard on top of that will it be ok to lay tile on that? I was instructed by an ‘expert’ at home depot and i’m starting to think I should have gone with my gut and put in the hardie board instead of the luan. I dont want to tear it up and also don’t want to build up the floor height with the hardie board now..
It’s really unnecessary to use thinset under hardibacker board. If you screw the boards down every 6 in you will have no problem. Been doing it for 15 years with no complaints from any customers.
I am laying pebble rock tiles over a 3/4 plywood sub floor covered with a membrane and sealed with Red Gard. I am using a polymer modified mortar. The area is 5×5, so I am not too concerned with some of the fears I have read about in the previous posts. Thank you for all the informative posts. Cheers.
Wow, reading horror stories. Now, I buying a townhouse in WNC with laminate flooring in kitchen, and all bathrooms. Just checking the procedure on lying down tile on wood subfloor. Please, as a homeowner do not trust anyone with your home without doing your research first. I had to rebuilt my home after hurricanes, and the Miami-Dade county inspector loved that I was informative and passed all my inspections. Read, research, and make sure the licenced contractor knows his/her stuff.
This article was informative.
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I have a concrete floor and I put plywood over it , can I install granite tile on the plywood.
I am not a professional but I do all my own work and own 3 rental properties
I have done bathrooms ,kitchens and dining rooms in tile directly over 3/4 inch plywood using thinset mortar and have had no problems with loose tiles or cracking grout joints
Just make sure the joists are sound and sufficient for their span and no more than 16 inches on center and that it is well screwed down
I plan on tilling my bathroom floor using 1/4 inch plywood and tiles over linoleum that was install 30 years ago when the house was built I was told that it will be ok as long as its one layer . My question is what will the heigth be with the 1/4 inch cement board ,and tiles pulse the linoleum be? I am concern about my door. Thank you
I want to put tile on plywood floors, and I hear all the arguments for putting something over it. My question though is about the KIND of plywood I have. The wood on all the floors is like particle board–it looks like pressed sawdust and absorbs moisture like a sponge. It doesn’t look like plywood I’ve seen with long strips of wood in it. Is this subfloor ok? Or do I need to pull it out and replace it?
You may need more support for laying tile on this kind of floor.
Please include a photo with your question so we can see the project area.
We accept photos at email@example.com.
Thanks so much!
You can’t tile on plywood because it expands and contracts but it’s okay to put down a backer board directly on top of this plywood?
If that’s the case, the backer board will shift loose over the same period of time due to the ply expanding and contracting, even if it’s screwed down.
Let’s be honest here. Good quality marine ply will be perfect for tiling.
Use a good acrylic sealer, use 2 coats of it, then put on a tanking system as it’s flexible.
Then use an adhesive that also has flexible properties, and get yourself a good tiler. Job done.
I put 6mm marine ply on my wooden floor boards and screwed it down every 6 inches. I then sealed it with acrylic sealer and tanked it. Tiler said the tiles will never shift as the prep work was great.
So yes, you can rule on ply. Just prep the area like your life depends on it. Spare no expense and do it right.
I plan to have travertine tiles in mud room and half bath, the tiles that need to be removed are 1 inch thick laid directly to plywood 20 years ago, should cement backer board be used first?
Installing cement board is necessary to waterproof ceramic tile floors.
But here’s an alternative: https://todayshomeowner.com/radio/tile-underlayment/
Good luck with your project. 🙂
how did people tile floors before hardieboard was invented in 1980’s? Surely they had tile floors before then. I don’t think hardieboard is necessary and think pro contractors are just trying to take advantage of you. Most people do not have problems when doing tile themselves directly to plywood.
Thanks for sharing your thoughts, Joseph. In this case, whether to use a specific product isn’t the concern.
Plywood expands and contracts at rates different from tile; this causes cracks to develop in grout lines or tiles.
On a plywood subfloor, you need a layer of cement backer board or an underlayment membrane between the subfloor and tile for the thin-set adhesive to achieve a good bond.
While most people may not have initial problems with laying tile directly on plywood, that will change due to seasonal expansion and contraction.