Cracked Tiles

[Rolly]

Hi all,

I recently finished a loft conversion and moved in, about 3 months ago.

Everything is settling a bit so there's the odd paint/plaster crack, nothing to stress over...

We haven't used the new bathroom because the shower was faulty and wayyyyyyy down the list of important things..

But it has some craked tiles, like about 20...

Most of them go along a horizontal line at 1.2m of the floor, so when I stripped them I was not surprised to find a joint in the plywood (13mm) substrate, that hadn't been knoggined... OK, so my plan was to cut in to the ply and insert a knoggins, then screw it all back together, but...

There's also several tiles cracked on a vertical line, this is again over a joint in the ply, but it's on a stud and the ply is screwed to the stud every 300mm or so.

So, I'm now thinking that my plan to insert knoggins won't be enough...

There's no tile board, just the ply,
nothing is even damp, let alone wet (but only because we haven't been using the shower)

Is there a better way to joint the ply ?

Am hoping to avoid stripping the whole wall and recladding with tile board...

I'd appreciate any thoughts 🙂
Thanks

 

[DHTiling]

Hi, it is expansion in the timber substrate and this will always be there , but it will also be timber shrinkage which is very common with new build but having ply walls has increased the risk of timber related movement.

 

[Alan.P]

As Dave says, you'll always have the problem with the substrate you have, and with it being a loft conversion there's only one way the water is going to go, best and most futureproof way is strip it, board it, tank it and re-tile, sorry if it's not what you want to hear.

 

[Bubblecraft]

Hi & welcome to TF. As above

 

[Diamond Pool Finishers]

:welcome:to the forum as Alan p say's above sorry whoever did you job was not -up to scrach IMO

 

[Rolly]

OK, Thanks guys, that's what I was worried about, but at least I know what's what... didn't want to just cover it up again and cross my fingers..

So my plan is to strip the wall of tiles and adhesive,

Cover with Hardibacker (or is there something better/cheaper/different ???) screwed down over the ply, making sure the joints are staggered and don't match any joints in the ply...

seal/tank the hardibacker

retile with "flexible" adhesive

Sound good ?
Cheers !!

 

[DHTiling]

If the option to remove the ply is there then that is the way but if not then you could use an anti crack membrane.. but the joints on the ply would need to be not butt jointed as this can cause heave cracking as the timber expands with thermal/humidity stress.. so opening the joints with something like a fein is possible.. but over boarding is an option as well but it is all that timber stress that concerns me...

 

[Peter]

Don't like tiling to ply but where it can't be avoided I tape all joints, helps a lot. Also use a rubber crumb fast flex adhesive if tiling straight to ply on joists. Over boarding/matting is the ideal way though.

 

[Alan.P]

If your going to tank I would just use plasterboard, what's the use ( apart from weight limits ) of using a backerboard only to tank it imho that is.

 

[Rolly]

Ok, will have to bite the bullet then..

Thanks all !!