Went and looked at a floor in a house my company built a few years ago. Ouch. The tile on the kitchen floor had long, straight hairline cracks every 4 feet.
Here’s the history. It is a new house with wood I joists. The floor was put on in the late fall, and covered with plastic and heated for the first winter. When I went to frame it the next summer, the OSB subfloor had deteriorated from trapped moisture to the point that I wasn’t comfortable leaving it, so I added a layer of 3/4″ plywood, glued and screwed down with 3″ screws.
The cracks appear to be right on the seams of the top layer of plywood (that is, if I butt my tape to the wall, the crack appears at four feet from the inside of the wall) (the top layer of plywood was put on after the walls were up.
Now here’s what I think happened. The yo-yos who tiled it put down 4 x 4 sheets of tile underlayment, and the seams lined up right on the seams of the plywood below. I’m not sure yet, but I wonder if they taped the seams, though I don’t know if that would have prevented the cracks.
So the question is what now? Can’t find matching tile, and the work was done in house so there is no sub to go after. I really don’t want to pull up the backer board–rumor has it that it is screwed down 6″ oc. I’m wondering if a crack isolation membrane would solve it. Or maybe I should just admit defeat and pull it up down to plywood and start over.
Watcha think?
Replies
damn!
That's all I can think of right now.
You going to take up the tile and try to save the underlayment?
Edited 8/20/2009 9:43 pm ET by rez
That'd be the million dollar question. It'd really suck if it cracked along the same joint again. Maybe the thing to do is to line up a grout joint on the crack.
http://www.johnbridge.com/vbulletin/index.php
might have some detailed info to help ease the burden.
I don't understand why you left the original osb sunfloor in place if it was moisture damaged.
"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
I am still amazed by my father who when he put the addition on the cottage (on 12" piers) doubled up the ply glued and screwed and ran ply 90 degrees to the first course, and laid tile on top. not a single cracked grout line or tile. It is probably a days labor to rip up the existing and put new tile, (HO's expense) save your name. Not much experience with separation membrane, however expense is probably the same, and you could not be solving the pre-existing problem.
The yo-yos who tiled it put down 4 x 4 sheets of tile underlayment, and the seams lined up right on the seams of the plywood below.
I wasn't aware of any tile underlayment that is 4x4?
Yeah, I thought that 3' by 5' was designed to help prevent seam-on-seam.View Image
I always thought 3'x5' was to fit so easily with most tub surrounds.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Ken...off subject...I recently saw one of those COEXIST things in the form of a sticker on the back of a car...know where to get one on the net?
Sorry to interrupt the conversation...but I still think they don't make underlayment 4x4...3x5 avoids that whole issue...right?No Coffee No Workee!
"COEXIST things in the form of a sticker on the back of a car...know where to get one on the net?"
Here ya go:
http://carryabigsticker.com/index.html?gclid=CJv-_MzOtJwCFU1M5Qodb1T7ow
Warning: High hippie quotient. ;-)Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
I'm currently using a combination waterproofing/isolation membrane (imper, by profix) this stuff is supposed to be able to span cracks up to 1/8" provided there is no inverse vertical movement (one side going up, the other down) .. Schluter is probably the same, so yes isolation should work ..
Pretty sure I've seen 4x4. Dunno how common it is.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
It could be that they used the 4X4 plywood underlayment that is more meant for vinyl installations.Or maybe they saw that you had already bolstered the floor, and put their tile directly on your plywood.
Politics is the antithesis of problem solving.
No they used a 1/4" cement board. The crew boss that was finishing the house (now fired btw) called me and told me that she didn't need a backer board because I had doubled the subfloor. I insisted and I have witnesses that tell me she used backer, screwed down every 6". One idea I have come up with is yanking the cabs so I could get enough tiles for a repair. What I'm not sure about is how to prevent the crack from telegraphing through again. I've heard of crack isolation membranes bur have never used one. I wonder how much thickness they add to the installation? That would be problematic. That's just an idea. The thought of yanking the underlayment is not appealing. Do you see any reason pulling the tile up and adding a membrane like ditra would not work? I know it ain't cheap, but pulling up the tile backer seems like brutality. Part of my motivation is to limit the disruption to the owner. This was an affordable spec house by the way.
I have also heard of the membranes.And in cases where I suspect ANY movement under tile, I use modified thinset. And if I already know of movement, I fix the movement best I can, then use modified thisnet, with that latex soup admix instead of water. That stuff makes the thinset much more like tire rubber.And I would at least consider using color-matched caulk instead of grout.
I won't be laughing at the lies when I'm gone,
And I can't question how or when or why when I'm gone;
I can't live proud enough to die when I'm gone,
So I guess I'll have to do it while I'm here. (Phil Ochs)
Would you really have any real change in height if you remove tile and the existing backer board back to your plywood? Follow this with the ditra and thinset layer, and then tiles once that is set-up.
Usg aquatough comes in 4 x 4 around here.
Well there you go then...No Coffee No Workee!
Sounds like you have it figured. The wet OSB has moved while drying, moved the plywood along with it, and if the tile backer was on the same joint pattern as the tile, it moved that too. I would suck it up, tear out the tile and backer, and redo the job. The HO will have to accept new tile in a different color/pattern, there's no way around that. Maybe they can get a new look they like. You can probably leave the plywood in place by running 3x5 backerboard and taping the joints. Coating the backerboard with Redgard or similar will give you another layer of protection. You could consider a membrane system that utilizes fabric if you really wanna kill it.
I've probably confused things a bit by talking about the "wet osb". It wasn't wet when I covered it with new plywood. It was bone dry. The moisture damage occured during the winter. The foundation was built in the late fall, and the subfloor was covered with 6 mil reinforced poly and the foundation heated over the winter. Water got at the floor and the poly just trapped it. It was somewhat swollen and somewhat soft in spots, but sound enough to frame a house on. If I am involved in something like putting a foundation to bed for the winter again, I would use 7/16" or something temporary so we could heat it, and apply the real subfloor during framing.
Do yourself and your customer a favor and tear up the backboard and tile. Start over with either backboard installed the proper way or install the Ditra, I personally would use the Ditra.
Hardiebacker is available 3x5 and 4x8
Jim x 3
When I went to frame it the next summer, the OSB subfloor had deteriorated from trapped moisture to the point that I wasn't comfortable leaving it, so I added a layer of 3/4" plywood, glued and screwed down with 3" screws.
Why would you have covered over that? That's your problem right there.
>>Now here's what I think happened. The yo-yos who tiled it put down 4 x 4 sheets of tile underlayment,
4x4? the backer board I'm familiar with is 3x5
Were your 4x8 seams over joists? Or between?
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurman
http://rjw-progressive.blogspot.com/
Rip up tile and backer, ensure subfloor is structurally sound and sufficient (min. 1 1/4") install Ditra, then tile and grout, no worries
Geoff
marson, save your good name and completely tear up the floor down to the joists and start over.
To help defray some of the costs maybe you can upsell them on a more expensive tile or floor warming.
sully
Well, my name isn't exactly on this. I don't really care about the expense (isn't coming out of my pocket--I get paid a salary). But the disruption of pulling out the entire subfloor out of an occupied house is immense. Basically I would have to move a single mom out of her house for over a week. I would have to remove all her counter tops, cabinets, toilet, etc, and put them someplace. Clean out the room below, and cover with tarps, etc. The only entrances go across this floor. Replywooding it would mean putting backer against all the partitiions and exterior walls. It would be huge. Plus, I don't really see why having that second layer of old OSB under there is hurting anything. One of the reasons I didn't pull it up in the first place is because it was glued down quite well to the joists. Just soft in spots to the point I thought it prudent to re cover it. The cracks are hairline. No evidence of vertical motion. I'm liking the ditra idea.I spoke with a guy who had more knowledge of what went on than I did, and the crew boss in question grudgingly put down the backer, but refused to put thinset under it. I also don't think she taped the seams. There is one long wall in the house that made sense to start the sheet goods. That is the wall we used for the top layer of plywood, and I'm nearly sure what we have is a joint in the tile backer, without tape, stacked right over the plywood joint. Thanks for the reply.
I have done 12" strips of Ditra (or Rolled Gold actually but similar stuff) over cracks in concrete when tiling a slab with excellent results so it is posible that you could go that route but I think the best solution would be to pull the tile but leave the backer board and then run Ditra over the whole mess and re-tile with new tile. Of course the backer board may chip up so badly when you pull the tiles up that you'll have to pull it all and start over, at which point you can run 4x8 Hardi backer with properly offset joints OR Ditra and come back at it. Patching is too risky and looks cheap to the home owner.------------------
"You cannot work hard enough to make up for a sloppy estimate."
12" strips of Ditra just over the cracks? Sounds good, but how do you deal with the change in plane over the rest of the floor?Or is the strip of Ditra in place of a CBU?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon
I'm not sure what a GBU is but we use this trick when laying tile over radiant slabs that are showing cracking both random and at our metal key-way screed joints. the rest of the floor we just lay the tile right on the raw slab. we set the crack membrane with thinset and butter it in with thinset on top to feather the transition from the ditra to the raw concrete. Saves mucho bucks which is my Scottish middle name.------------------
"You cannot work hard enough to make up for a sloppy estimate."
Marson,
Backer installed in register with underlying ply (and OSB?) - Strike 1
No thinset under backer - Strike 2
Backer seams not taped - Strike 3
The backer will come out pretty easily (relatively) if it wasn't bedded in thinset. Take it out and see what the ply (and or OSB) looks like. You don't need to do under the cabs - leave them in place. Cut out and take up the ply/OSB if you have any question about the OSB. Then block and put down new material. Thinset your backer. Offset the backer seams from ply seams - use plenty of screws/nails. Tape the seams and retile.
My 2 cents.
Jim x 3
I guess the Ditra is only about 1/8"-3/16" thick, but I was wondering if that hump in the middle of a floor would cause any problems.I was wondering if you used the Ditra in place of a Cememtitious Backer Unit (CBU).
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I like the Ditra much more than the CBU but still use both. That little hump feathers out with a 1/4" notch trowel or bigger.M------------------
"You cannot work hard enough to make up for a sloppy estimate."
I'm the least knowledgeable person here
But here is something called flex versabond that we used on concrete slab in basement bathroom
I thought they told us at HD that is was recommended because it would tolerate some slight movement of the concrete slab
???
http://www.custombuildingproducts.com/ProductCatalog/SettingMaterials/LatexPortlandCementMortars/VersabondFlexFortifiedThinSet.aspx