DublinDilbert wrote: Tiles shouldn't be moving and also should be level, the adhesive should take up the difference in height. Thousands of floors all over the country are tiled on ply wood and are absolutely fine. The last few i've done i used magnesium board, available from most builder providers and it does the job quite well, won't absorb water, gives a nice stable surface for tiling on.
seefin wrote: » Tiling already done on pine floorboards though. Do we have to take up and start again, this time using backing board or what. There's Cory board down(not sure if spelt right). Maybe only a few tiles that aren't level but we're afraid that the unevenness was caused by tiles moving and that the problem will get worse over time. we haven't paid balance yet to tiler and want to be sure won't get worse.
RobbieMD wrote: » What’s under the tiles looks to me like Qmat. A movement mat for tiling over.
Lumen wrote: » But that's for lateral decoupling, not for stiffness. The tiles have lifted because there is vertical movement in the substrate. It's a bizarre choice of materials for a really simple job. Baffling.
RobbieMD wrote: I was just addressing the thought that the tiler had used corriboard when it looks like it’s a movement mat he’s used.
RobbieMD wrote: » I was just addressing the thought that the tiler had used corriboard when it looks like it’s a movement mat he’s used.
Lumen wrote: No, as far as I can tell that movement mat is only a couple of mm thick and doesn't have a corrugated profile.
seefin wrote: » A few tile companies we called into today have said that qmat alone should be fine on floorboards? It's a new product and same effect as backer board
Lumen wrote: » No, as far as I can tell that movement mat is only a couple of mm thick and doesn't have a corrugated profile. I thought you meant it had movement mat on top of the corriboard.
cheif kaiser wrote: » Had a new bathroom installed about a year ago and they used Magnesium board screwed down to the floor boards. No issues with movement whatsoever. Have also seen many bathroom installed on top of Ply and many have had issues such as cracking along the seams and lifting in areas. Magnesium Board seems the better option IMHO.
mick121 wrote: » Just throwing in my 2 cents here.I am not a tiler but have worked alongside and with them for many years,many moons ago and I do tile myself every now and again.What I was shown may be outdated but has served me well for many years.Check all floorboards are fixed well and rectify if needed.6 mm wbp plywood screwed down every 4 to 5 inches with no.4x25 screws.Your talking upwards of 250 screws per 8x4 sheet
K.Flyer wrote: At the end of the day, whatever they used was not fit for purpose. It is a shocking job and the tiling company should rectify it, even if that means pulling it all back up and doing it right. Back when we used to do full bathroom renovations it was the method as described by Mick121 above that we followed and never had any problems with movement and tiles coming loose.
seefin wrote: » Am so confused now. Bathroom guy said plywood more likely to cause issues and the qmat is best option. He's said they screwed down floorboards and then used the qmat. Thinks maybe his tilers just used too much adhesive in places and that's why some tiles are raised. Going to get a few tilers to call in during week and see what they say. I don't want hassle of ripping them out so hoping it's only the few kick up ones that need replacing and not entire floor. It's only bathroom in the house and we've already had 7 days of disruption during the refurb. Can't cope with 3 more days if entire floor has to come up. But if has to then it has to
Odelay wrote: Could they have installed the board in the wrong direction? Across the grain instead of with it?
