Getting ready for
kitchen addition…question regarding tile floors. (yes – I’m a DIYer but will be subcontracting all the work but I am curious …)
Will be using 12″ ceramic tiles, no radiant heat or other exotic devices- just a basic tile floor.
Two questions
A) Is a 3/4 ” subfloor sufficient to minimize deflection / prevent problems with tile cracking etc … – (new addition will span 8′ x 20′ over I- joists) or do I have to do two layers or 3/4″ subflooring.
B) I read on the back of the thinset that one should not use thinset to adhere backerboard to an OSB subfloor. What does one use ….. in this case? If I were to use 3/4 plywood ( one or two sheets thick ) do I even need the backerboard? I’m not worried about water in this area so….. provided the subfloor provides a good base for the thinset to “grab and hold the tiles,” why would I need backerboard? Is it all a marketing conspiracy to say one needs backerboard WHENEVER one tiles.
Whatchall think?
Ralph
Replies
Backerboard stiffens the floor and especially with the large tiles ie:12x12 will prevent the tiles from cracking. So yes a backerboard is prefered. If you don't want to use backerboard than at least use two layers of ply with the joints staggered as best as possible.
Having said all that. I would like to convince you to use anything else but ceramic tile in the kitchen. Drop anything and it will break faster than you can say " oh sh". At least with wood or lynolium there is a chance it will bounce. If you have small kids, make sure the good stuff is well out of their reach. Yes tile is beutiful and durable, but is unforgiving if you drop anything.
As far as the mastic for the backerboard I will defer this to the more qualified opinions of others.
Good luck and post a picture of the end results.
When I used to work for a flooring contractor back in the eighties, we put quarry tile down on 3/4" subfloor directly, in a thinset morter bed. Never had any problems that i know of . Obviously the wonderboard will make it stiffer which is important to keep deflection from breaking the bond. We only used wonder board on big jobs. I am being ASKED to do a floor again about twelve years later. There is 3/4" Ply subfloor down and I plan to use the wonderboard of course. But thinking about all of this again I realize that OSB is now a very common choice for sub flooring. I get the Idea that it won't matter if you put the wonder board over the OSB. since you are screwing it anyway. As long as you have your 1 1/8" of subflooring
Is there enough glue in the board to keep it from absorbing the moisture from the mortar, or is there? Who really knows at this point.
But what about the deflection factor . Does OSB have the same deflective strength as 3/4 ply subflooring"I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground"
You may have gotten by with smaller quarry tiles because the deflection happened in hairline cracks in the grout. Larger 12" tiles will break free or demonstrate cracks eventually.Excellence is its own reward!
1) Setting tiles on a subfloor no matter what will crack.
2) you don't give any information on the floor framing ( I-joist size? O.C dimensions?) but remember a ceramic tile has a ZERO deflection tolerance. If the floor is not framed correctly expect big nasty ugly cracks. If it never happens then feel lucky and happy. In this case alittle overkill will keep from doing the job twice.
My rule is if I wouldn't park a car on the floor I won't tile it.
Couple thoughts...
1) get yourself a copy of the most recent Tile Council of America handbook (www.tileusa.com). It contains detail drawings and specs for almost every type of instalation out there.
2) regarding the backerboard issue... I would definitely use backerboard, attached per the mfg's instructions to a minimum 19/32" exterior grade ply subfloor. Avoid OSB because the amount of expansion and contraction due to changes in moisture makes the potential for cracking much greater than with EGP.
3) Avoid mastic. IMO it's useless except for hanging decorative tiles in a 100% dry location. Use a premium latex-modified thinset to attach the backerboard to the ply and again for the tiles.
4) I completely agree with the comments about deflection- all of these specs may seem like overkill but the fact is that tile has virtually no tolerance for deflection so the structure to which it is adhered must be extremely solid.
Good luck!
Andy
I agree with the other posters, use backerboard. It is a small price to pay for the extra longevity that you'll realize. Not to open a can of worms, but I've had better experience with Hardi that Durorock. I find it easier to work with as well. If you're having the work done though that won't matter to you.
Here is a word of caution: If you've selected a tile setter and they haven't strongly advised you to have backer installed, I'd consider getting another tile setter. For years plywood was the substrate of choice for tile, now we have better products available. Again, I agree that a poly blend thinset mortar is the best for attaching the backer. I know plenty of tile people that don't use thinset but just nail or screw the backer to the subfloor, and it seems to be okay. Again though, it's cheap insurance, and the reccomended way is to bond it. The seams should be taped and thinset applied also.
As for the dropping and having things break. Think how often you drop things, unless it's frequent it shouldn't be a big deal. If you like the look of tile, go for it. We've had tile kitchens in several of our personal houses and I don't think we broke much more because of it. My wife has decided with all of the wonderful laminate and solid surface selections now that she doesn't like tile counters in the kitchen any more. Our last house had granite counters, and they looked great when they were clean, but set a glass on them and it looked dirty awfully quick.
Depending on the look you're after, there are some gorgeous slate's that work well in kithens.
I've been giving this some thought. After reading some of these posts. And after reading some of the other threads, which speak to the same subject. I've decided that the reasons for applying the mortar under the wonder board, are different, than those for using it under the tile.
Since The wonder board gets screwed down , unlike the tile, this mortar has less of a bonding function.
However, the mortar bed has a leveling effect any defects in the subfloor. A high corner, a raised nailhead ( although i always check for that ) could become a pressure point that might grate on the wonder board in a high traffic area. That might cause it to crack, (the wonder board.) Which in turn might cause the Floor to fail.
I am thinking New construction here with all of this. And still I'm somewhat curious. If you screw it every 4 inches, and level and fill the seams up top. Why would it need the mortar? "I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground"
Great advice from everyone in the thread!!!! I'll probably go with 3/4 Plywood and backerboard. Seems there are too many variables with OSB.
Lastly thanks to veryone in the string for the wonderful advice.
Does' anyone know how to reply to all in the string?
Ralph
Does' anyone know how to reply to all in the string?
Yup! When you get to here, just hit that down button above and click the first thingy that says ALL. Then type like this and click on the post button
Down
here.
Got it????? Good!!!!!
Chuckle. Being half french canadian I tend to talk with my hands alot, even on the phone or when I'm typing.
Ive got the same situation kitchen tile over a sub floor. im going with hardibacker..butttt If your a bit nervous about using it. I would talk to the tile setter or "a" tile setter about floating it. It will off set the floor a bit but it will give you a solid base to set the tiles and they wont crack and you wont have any deflection in the floor. Darkworksite4: When the job is to small for everyone else, Its just about right for me"
I am a DIYer too. Background in architecture. Just did my kit, considered tile (wife like the look) but used Formica brand laminate floor. They are the only ones with realistic looking tile patterns in 24" X 24" panels. Looks great, can clean it with a wet tissue. Helpful with kids and a dog that drinks almost as much as she spills.
If you do decide to go with tile consider the following:
USE THE UNDERLAYMENT. PUT IT DOWN WITH THINSET. The underlayment to consider here is hardibacker. Strange stuff, but it seams to work. Used it on my bath floor. It flexes some so it will not transmit a crack to the tile like Durock. The thinset under the underlayment is to bond the two layers together and prevent any flex movement. Also acts as a leveler. The floor is considerably stiffer with it. USE IT. Screw every 4-6 inches.
Remember, it is easier and cheaper to add all layers (with thinset) before your tile is done.
Are we talking about ceramic or laminate flooring here
"I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground"
Edited 8/17/2002 11:23:36 AM ET by Edgar76b
Both. Sorry, thought it was clear.
I considered using tile but went with laminate instead for my kitchen. My advise was to consider laminate, but if he still wanted to do tile then refer to paragraph 2. I also did a tile job in my bath , and am doing another one at my office. Not rocket science. Just take your time, and put in all your "insurance layers" before the tile goes down.
I just read your message about replying.
I can't find any of the buttons "down" etc. Am I blind?
Please help. thanks
Yes, that is to say after hitting the "reply' button and arriving here on the post page, click on the triangular down arrow that is directly in front of the 'others' button. Then you can click on 'all' from the selection.Half of good living is staying out of bad situations.
Regarding using a poly blend thinset mortar between hardibacker and the existing subfloor.
I intend to install 12 x 12 slate, but I am curious about thinset between. My subfloor is a combination of 3/4" plywood that was glued and screwed to the joists where I had to patch the subfloor (ductwork underneath) and the bulk of the floor is 1 x 4 tongue and groove pine boards. Joists below are 2x10 (old rough cut type) at 16" centers.
Where I have slight irregulaities between plywood and 1x4 t&g subfloor, should I use some kind of self-leveling, poured in place product first, then thinset, then screw down the hardibacker? Or, can I just trowel the thinset a little thicker in places.
I am sure that when I put down the tileset that will also make up for irregularities, and also, slate isn't the most consistent material.
Am I making a mountain out of a molehill?
bump
Am I making a mountain out of a molehill
Yep. I'd just put thickset (more thinset) in there.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
First things first. Do you know if you're O.K. on deflection? It should be l/720 for stone. Check here:http://www.johnbridge.com/vbulletin/deflecto.pl
You shouldn't tile directly over the tongue & groove boards. You need to put plywood and cement board over them first. Even better, cover the whole floor in tarpaper, put down metal lathe and put a drypack mortar bed over the floor. This will fix the leveling problem and provide an excellent substrate for 12x12 slate.
Billy
Edited 2/21/2005 7:43 am ET by Billy