New member with tiling problem

[Scott]

The builders overlaid with 9mm ply as a base for the tiles. I asked them at the time if this was enough, as I have some amateur experience several years ago from our last renovation project before mats were so widely used where we used 12mm ply. I was told that in combination with a mat it would be fine, and they had also fixed any loose board before putting down the ply.

They were wrong ^^

The ply is way too thin and the decoupler is being used for the wrong type of deflection. I doubt that the temperature change will be the cause as the decoupler should have taken that movement. I havent seen a floor yet that blows because of a temperature change.

Is the adhesive all cracked and is it stuck to the mat or the tiles or bits of both? Got any pics?

 

[Max@ableskills]

Hi. Hope you get this sorted as pain free as possible. Please let us all know how you get on.

 

[rhgnag]

Hi Scottley,

I have a few pictures below where we lifted a couple of tiles in the shower room. The builder was hammering to remove the tile, but the top layer of the mat literally lifted off. You can see the tile mat has separated for some reason anyway. The base of the mat is very firmly fixed to ply. The top is a bit less clear, but still seems pretty solid. It seems like the movement is from the mat separating rather than the adhesive failing, but it could possibly be a bit of both. The grout was only starting to show some hairline cracks, but the floor was moving significantly in places and making a flexing sound like the mat rubbing against itself. The main bathroom which we have left until we can get some more tiles as they are not in stock is over a much larger area (as it is a bigger room I guess).

Rob

 

[DHTiling]

Have you checked to see what the perimeter joint is for floor to wall..?

If this is too tight then lateral stress will cause the tiles to tent up and separate from the fleece.. i did ask this a few posts up..?

 

[rhgnag]

I should also add that the flexing noise stopped once the tiles were removed. There is a very small amount of movement in the ply, (I know it is not thick enough) but it is definitely not making the same amount of noise or movement as it was before the tiles were lifted.

Rob

 

[Scott]

Thatll be the noise of the tiles pressing agianst the adhesive/mat where its lifted.

How big an area is it?

 

[rhgnag]

Hi Dave,

I did look at this, and it is quite tight, as there is no skirting the wall tiles do sit on top of the floor files at least to some degree. I would have to take a tile off the wall to truly know what allowance has been made. I would need to do this in the presence of the builder and tiler, so will wait until they are available. The section shown is on a door threshold so does not butt up against anything.

Rob

 

[rhgnag]

Hi Scottley,

The shower room is only about 1.5m x 1m tiled area, and about 3 tiles were badly affected.

The main bathroom is about 7 sq m tiled floor, with probably around 6-7 45x45 tiles affected, maybe more to a minor degree.

Rob

 

[DHTiling]

The section shown is on a door threshold so does not butt up against anything.

It will be to the left and right though..

If it is deflection related then this will do it as well.. as the bottom of the mat( fleece) will want to hold to the ply and the top ( polyethylene) will want to hold to the tiles.. hence separation..

 

[rhgnag]

Hi Dave,

Well this seems like the front runner at the moment in the cause of the problem. The tiler's supplier come on Thursday, but the wife is getting impatient.

The ply was also laid under the shower trays which have quite heavy glass doors so may need additional support if the ply is cut, but I don't want to dismantle the whole bathroom unless absolutely necessary so need to maintain levels.

I guess we have to do what we have to do on this. I was thinking the the course of action we would take would be to cut the ply around the shower tray, securely fix the boards again, then if we fix a better base such as a 12mm tiling board, ditch the mat and ensure we leave an expansion gap. Hopefully I haven't missed anything.

Thanks for all the advice. Will try and let you guys help someone else out as I feel I have had enough of your precious time already.

Rob