Question about subfloor for tile job
Happy Holidays to all. I installed 3/4″ OSB T & G over existing ‘ancient’ 1/2″ original subfloor and used PL premium as suggested here with my last post. Now, it’s time to get the bathroom floor ready for tile. Can the tile be installed directly over the wood subfloor, or should I use a durarock subfloor over the OSB, before doing the tile work. Bathroom is 10′ X 10′.
Thanks for your help,
Jeff
Replies
I wouldn't put tile directly on osb. Plywood maybe. Screw down a layer of 1/4" hardiebacker. Put a layer of thinned thinset under the hardie first, so that it will fill all the small voids and fully support the hardie.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Thanks for the reply. Does the durock need to be taped after being screwed down, or can I just tile over with recommended adhesive and tile.
Thanks again.
Jeff
Tape seams with fiberglass tape and thinset.
Jim
Never underestimate the value of a sharp pencil or good light.
You're supposed to fill and tape the seams just like sheetrock.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Ditto Fasteddie's post except.......
Install (staple) a layer of 30# felt over the OSB, tape the seams with Tyvek tape then thinned thinset and 1/4" Hardie or cement board of your choice.
Screw down the cement board according to manufacturer's schedule.
Your downstairs ceiling will like the felt when the kids decide to have a water fight, the whirlpool overflows a bit, or etc.........
Jim
Never underestimate the value of a sharp pencil or good light.
What FastEddie said. How do I know? Not cause I'm an expert tile setter. I posted a message about popping noises coming from my new porcelin tiles. I went directly over plywood and I was scolded for that buy all the tile guys around here.
Apparantly, plywood or osb are NOT acceptable subtrates. You need to alow the subfloor to move independantly of the tiles, movement from expansion and contraction or minor deflection, otherwise the bonds will eventually come loose. Also, thinset does not bond very well to wood.
Don't be a Sorry Bukaroo like me : ( use the durock, or other acceptable substrate like "Ditra"
See that guys, I hope your proud. I can't save myself, but I can save others.
Edited 12/30/2005 6:04 pm ET by xosder11
Apparantly, plywood or osb are NOT acceptable subtrates. You need to alow the subfloor to move independantly of the tiles, movement from expansion and contraction or minor deflection, otherwise the bonds will eventually come loose. Also, thinset does not bond very well to wood.
Tell that to the builder that I have been working for. They are one of the largest here in town. (Also the cheapest, by their own admission) They supply 3/8" ply for subfloor under ceramic tile.
They also gave me c*** because the grout lines cracked when the house settled. Now, I do not like taking s*** for problems beyond my control.
How do I know that the house settled?... when I got there, their super was busy taking apart and reshimming the interior doors; and the casing joints had all cracked sideways. (all twisted away from 90)
I tried informing them of the proper method of installing tile as per FHB article. I got laughed at by the desk jockeys, and was told that it was too expensive; they never had problems previously; and to mind my own business.
locolobo
Edmonton, Alberta, Canada
I've always thinset my CBU directly to the subfloor then use screws.
The secret of Zen in two words is, "Not always so"!
When we meet, we say, Namaste'..it means..I honor the place in you where the entire universe resides, I honor the place in you of love, of light, of truth, of peace. I honor the place within you where if you are in that place in you and I am in that place in me, there is only one of us.
We have a couple of issues here:
First, the TCA (Tile Council of America) does not warrant going over any OSB with tile. Plywood yes, but not OSB. (Please, lets not have an argument here by those who claim OSB is just as good as Plywood). However there are 2 manufacturers who will warrant going over OSB; Hardibacker and Schluter's Ditra. Personally I love Hardibacker and have been using it for years with no problems. Always use thinset under the CBUs!
That said I have recently used Ditra on 2 jobs and am thinking of converting. Its lighter, faster, no nails/screws, and with some addtl material can be waterproof.
It does take an open mind to get over the fact that it is not stiff or heavy, so you don't feel like it's doing anything, but it actually does more than what the CBUs can. It allows the tile to move, should the house settle or the plywood shift. I then convinced HD to carry it in stock in my stores. It runs a little more per foot than CBUs, but more than makes up for it with labor; you just spread thin set and roll it out. We had it for 3 months before the FHB issue featuring it came out. Then sales took off.
KNOWLEDGE IS POWER!
Here is an interesting product.I am guessing to compete with Ditra.It is GLUED DOWN and then coated with thinset.http://www.tavytools.com/thin_skin.htmlI believe that it can go over OSB.I found it at Lowes online when doing a search for underlayment for vinyl.So I don't know anything else about it.
As I said in my post above...same as you said.Thinset the CBU to the substrate. I think anyone that skips that step doesn't know what they're doing unless I'm missing something here ...its been known to happen...lol.
Also...I too love Ditra except for the price and ite really hard to find in these here parts which makes it problem. If I were a full time tile guy I'd probably just buy a giant roll but the amt of tile jobs I do doesnt warrant that layout of money.
Too bad HD doesn't carry it in the US because they do carry other products of their here. LAst time I went skiing in Canada I stopped at a HD on my way home and picked up a roll but thats long gone.
BE well
andyThe secret of Zen in two words is, "Not always so"!
When we meet, we say, Namaste'..it means..I honor the place in you where the entire universe resides, I honor the place in you of love, of light, of truth, of peace. I honor the place within you where if you are in that place in you and I am in that place in me, there is only one of us.