Hi guys. I have a problem that I need expert help with. We have a small bathroom in a roof conversion that is prone to some movement. We laid plywood and put large porcelain tiles down. The grout keeps breaking up and I'm guessing there is still floor movement. The tiles haven't moved. Does anyone know of a VERY VERY flexible grout? I think I'm going to end up with something that looks a bit like plastic but who cares, it's got to be better than hoovering up grout almost every day. Any help would be greatly appreciated. Brendan in Belfast.

What thickness of ply did fix

Originally Posted by whitebeam

What thickness of ply did fix

Just what I was thinking

this may not cure it if the movement is too bad but i would try it,,buy a bal non flexi wide joint grout and also bal gt1 admix,mix the 2 as per instructions and apply,,see if this makes a difference

i'm with jamie(kilty) on this, a 2-part grout but it might still not work!

Thanks guys. Sorry, I had to go out for a while. The ply was pretty thin. Re the solution (a bal non flexi wide joint grout and also bal gt1 admix,). I'm going to try this myself and spend some time doing it properly (maybe this is madness - please advise). Assuming it is doable by me, as I'm a complete novice, I don't even understand what the information means. Kilty - can you write it out like you were sending a small child to the shop to buy it for you? Thanks. B

I think your problem lies with your ply being too thin. British Standard is a minimum of 15mm ply any less than that may give you problems like you are having

A quick fix isn't the solution here..

The grout is cracking for a reason and this needs sorting to make it last.

IMO Deflection is the issue.

Go on, how thin, 6mm

I just looked in the garage - afraid to say but it looks about 6mm. Please don't tell me I have to lift the whole thing and re-do it. My missus (a fearsome creature of only 4'9" and 6.5stone will suddenly become very aggressive!

I'm afraid so... the grout is cracking due to this and then the tiles will come loose.. then you will be deffo for the high jump..

Originally Posted by tilewell

I just looked in the garage - afraid to say but it looks about 6mm. Please don't tell me I have to lift the whole thing and re-do it. My missus (a fearsome creature of only 4'9" and 6.5stone will suddenly become very aggressive!

your in trouble mate.....
yep it all needs to come up

Without a doubt you have deflection issues. I'd check how well your tiles are actually fixed, as I reckon a few of those will have blown too. As for a "quick fix" I would suggest that you use an epoxy grout as nothing else will remain intact.

Good luck, but your best bet is to rip up and prep it properly.

Ooops, just read the 6mm ply comment. Deffo rip out and start again - sorry.

Somehow the word thanks doesn't seem appropriate at this point. I can think of others but they wouldn't get through the system. I'm off to cry! Before I go, does it get worse? Are all thge tiles useless? Will they break when being lifted?

tilewell - (not quite an apt name)

Anyway as others have said the grout cracking will be due to inadequate floor preparation and the way forward is to remove and replace.
In the short term the most flexible solution would be to remove all the grout and fill all the joints with a small nozzle and big tube of rubber silicone - colour to be your choice.

Face the music now and get it over with, then once it's fixed properly you can forget about it or this is going to haunt you for years

Thanks John and co. On the name, I was trying to be ironic! OK, I accept that it all has to come up. I even accept that this is going to cost a small fortune because she who must be obeyed will want the same high quality tiles again. That said, it can't happen until after the new year as the finances won't allow for it. John - what product (Silicone/rubber) do I buy to make good for now? B

depends on what adhesive you used

the grout breaking out is the thin end of the wedge your tiles will break and come up

so the sooner you get them up the less damage will be done

Hi mate, sounds like your overboarding is not solid enough hence the grout cracking.

If you're wanting to regrout yourself, the Bal would be a quite a costly route. If you're in North Belfast, Huttons on the Shore Road will sort you out with Biscem vitri grout and Flexibond additive for in and around a tenner. By the sounds of things it'll only be a short term solution, though.