WHEN MY IN-LAW’S HOUSE WAS BUILT 23 YEARS AGO ABOUT 1000 SF OF CERAMIC TILE WAS LAID W/O BACKERBOARD DIRECTLY ON 23/32 STURDIFLOOR W/ REGULAR THINSET. OF COURSE IT STARTED CRACKING ALMOST IMMEDIATELY —- NOT EVERYWHERE, BUT IN EVERY ROOM, AND ALWAYS ALONG THE PLYWOOD EDGES (IN BOTH DIRECTIONS, SOMETIMES CHANGING DIRECTIONS IN MID-TILE). WE HAVE PLENTY OF THE ORIGINAL TILES LEFT, AND MY WIFE WANTS TO REPLACE SOME OF THE MORE OBVIOUS ROWS. ANY SUGGESTIONS —– FLEXIBLE THINSET? REINFORCEMENT FOR THE THINSET? STABILIZING THE PLYWOOD FROM ABOVE OR BELOW?
THANKS
Replies
what size our your floor joists and how far are they spanning?
2x10's 16" oc 8' span
"2x10's 16" oc 8' span"
Well, that's too bad... your joists are fine. Sounds like the underlayment is the culprit.
It's a do-over IMHO.
Jim, please turn off the caps lock. It's hard to read.
Are you sure the span is 8 ft? That seems short. Maybe the room is only 8 ft wide, but the joists span further?
What you say you have gives a deflection of L/1600 which exceeds even the requirements for natural stone.You could go up to 15 ft span and still be within ceramic requirements at L/390."Put your creed in your deed." Emerson
"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
No that's the span ---- it looks like they added a tripled 2x10 girder on loly columns to reduce the span down to this 8' number under the primary area of easily-apparent cracking. There is just that one layer of sturdifloor between the joists and the tiles and nothing else
Does the 3-2x10 look like it was added recently? maybe the floor flexed and cracked the tiles before the beam was installed."Put your creed in your deed." Emerson
"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
Probable that the 3-2x10 but the cracks go in both directions all through the house (it might have started in the area over the add-on girder). Still i was hoping there might be some speciality adhesive or thinset, or some mesh or a thin layer of aluminum ------ I'm grabbin at straws here to come up with some seciality idea
I'm interested to hear others comments who've faced this situation, but I suspect there's little to do to stabilize or reinforce that floor now without replacing the tile. The rows you replace will likely crack again regardless of thinset used if the subfloor is moving enough (vertically or horizontally) to crack tiles.
On the other hand, if the real problem is wide joist spacing, or inadequate joist sizing under the ply, then you might be able to address those issues and add enough stiffness to address the cracking. Then you could successfully replace cracked tiles and try to match the 23 year old grout.
Were it my house, I would start over given that the tile has already given 23 years of service.
Could be lack of adequate adhesive coverage. I've seen that before, where the tiles pop up really easily, and you can take one look at the bottoms and see that the original installer didn't get a good coverage of the thinset. Lots of voides and bare areas.
Also, the plywood may have sucked all the moisture out of the thinset before it cured properly. If the thinset comes off the back of the tiles like powder, then this would be my guess.
Pete Duffy, Handyman
THEY'RE STUCK DOWN TO THE FLOOR REALLY WELL. IN FACT IT'S A MAJOR EFFORT TO GET THEM UP. RIGHT NOW WE'RE USING THE SHORT END OF A WONDER BAR AND DRIVING IT WITH A 3 LB HAMMER ---- WE'RE POUNDING SO HARD THAT I SCORED THE GROUT FIRST WITH A DIAMOND SAW IN MY ANGLE GRINDER SINCE I WAS FTAID I'D TRANFER A CRACK INO AN ADJACENT UNBROKEN TILE
Edited 4/9/2007 1:58 pm ET by wilsonjim
Please stop yelling,
I think its a do over as well, but, you could try mesh over the ply. seams. I've never done that, but I thought i'd throw it out there and see if ya get a yea or nea.
If its cracking its because tile is supposed to be laid onto a membrane, like Hardibacker, Ditra, Wonderboard etc. Plywood and Tile have different expansion rates, hence the cracking.Indeed I would be surprised if it didn't crack.Regards, Scooter"I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934
Another thought is to check how well the plywood is fastened at the joists. Sometimes with only nails, they work loose and the plywood itself is flexing.Pete Duffy, Handyman
lets get real- This is a serious problem. I like Mike Holmes' solution to just about everything, ready?
"if the foundation is shaky, then you gotta fix it" and I think that applies to everything. You know you can replace a couple of rows and even use caulk to allow expansion etc but it wont be right.............
Tear up the tile, (that even types painfully) fix the subfloor, retile and enjoy until the cows come home.
Dont do what most homeowners do and try to cover it up with a quick fix, not worth it.
contact cement
You know, not to generalize, but the 29% of people who still support President Bush are the ones who love to pronounce themselves more patriotic than the rest of us. But just saying you're patriotic is like saying you have a big one. If you have to say it, chances are it's not true.
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You've gotten good advice here and you know what you should do, but if you're intent on trying to fix just the cracked tiles, here's what I'd do.
Pull up the broken tiles and make sure the sub-floor in that area is secure. Then paint the sub-floor with a crack isolation membrane like Red-Guard. It's thin so it won't raise the tile above the other tiles, but it should decouple the tile from the sub-floor, hopefully preventing further cracks. Reinstall tiles with a good quality thinset. If it doesn't work, you won't be any worse off than you are now.
No guarantees and good luck,
Jerry