Bathroom Floor tiles coming loose. Advice Please.

[ptoddy26]

Hi guys

Was hoping I could get some help / advice on whats gone wrong.

My bathroom floor is 18mm WBP Ply on top of the floor joists. I put lots of noggins in as well. Once done even with a glass of water on the floor and jumping there was a very slight quiver of the water but you could only just notice it so I think it's sturdy enough.

I had a product called fastheat which came with my UFH (see pic).


WP_000083 by ptoddy26, on Flickr

Wasn't going to use it but thought what the hell I may as well. This went on top of the ply.

I then used Mapei super flexible adhesive (see pic) and Mapei flexible grout.


WP_000082 by ptoddy26, on Flickr

I have some tiles that have come loose so I have taken them up. If i'm very careful I can easily save the UFH so not too bothered about taking them up. The tiles I have taken up shows (I think) that the adhesive has bonded to the tiles but not the floor. I've attached some pics for you to see.


WP_000080 by ptoddy26, on Flickr

The back of the tile seems to have adhesive bonded to the back. But the next pic shows the floor which doesn't seem to have adhesive bonded on it.


WP_000081 by ptoddy26, on Flickr

The pink stuff is the fastheat. Have I made a mistake in using this product? Or is it the webbing in the UFH that has stopped the bonding to the ply? To make sure should i cut the webbing out, sand the fastheat primer off and reapply the adhesive. Or do you guys think it's something completely different?

Thanks in advance for your help.

Paul

 

[lukeb]

To me looks like faulty installation....

 

[macten]

Looks like the mats been installed upside down.

 

[White Room]

I would have self leveled the matt before fixing tiles....

 

[ptoddy26]

Lukeb - Ok could well be. But can you explain why and what I should of done? It's fine telling me it's faulty installation but I need to learn why.

macten - I don't think the mat is upside down as the sticky side of the tape is stuck to the floor. But even if it's upside down the only difference is the sticky tape is up instead of down.

 

[macten]

As has been said, thermal boards on top of ply, then UFH mat, then encapsulate in SLC and tile.

 

[ptoddy26]

I'm ok taking them up and staring again. But if I do as said above and the adhesive hasn't bonded is it the adhesive? I'm just trying to understand why in my pictures above the adhesive isn't stuck to the floor and if I go a different route, as above, can I use the adhesive I have or do I need different?

 

[Tony73]

Hi, did you prime the floor before tiling? Did you check if tile adhesive is not out of date? or even if its not out of date, i had palet of faulty adhesive.

 

[ptoddy26]

Hi tony73. I only primed the floor with the fastheat that came with the UFH. I didn't check the date on the adhesive but just looked now and it's 19/03/12 and I only bought it 3-4 weeks ago so must of been out of date when bought. Would that not also cause it to not bond to the tiles as well though?

 

[ptoddy26]

Looking at the bag again that date may actually be the manufacture date. The bag says 12 months from date of manufacture so I assume the date on the side of the bag is manufacture.

 

[Tony73]

yes than , adhesive should be ok, and UFH mesh dosn't stop from good bond with floor. I would spread adhesive with flat side of trowel on to UFH and then with notched side, or use SLC first, then DITRA MATT and then tile.
Maby other members will know why adhesive didn't bond with the floor.

 

[AliGage]

So at what point after tiling your floor did you use the UFH?

 

[ptoddy26]

Hi AliGage - After the adhesive I gave it 2 days before grouting then gave it another 2 days before turning the UFH on. Only turned it on for 10 minutes just to make sure it was still ok. Haven't put it back on since.

 

[AliGage]

How long does that primer take to dry, and how long did it have to dry before tiling.

To be honest i agree with Whitebeam to bury the mat first, then tile as you would and back butter. But it looks to me like the bed wasn't substantial enough the UFH was prehaps left on a little longer than 10 minutes. Or have you got VH pipes directly under the floor at your heatings been on?

 

[ptoddy26]

AliGage - I think i gave the primer 2 days to dry also. I have got central heating pipes under the floor and looking at it the tiles that are coming loose are the ones in that area. should i have turned off the heating for a couple of days?