Potholes in 1 year old Travertine

[stuartmcc]

Hi,
I would appreciate any advice. We had our hall and kitchen floor tiled in travertine Christmas 2006.
We have got two problems:

1. Some of the tiles now have potholes in them. it is like the fill that has been used in the manufacturing process has given way and a pothole has formed. It is not as if it is all in high use areas but seems to be very tile specific. I want to go back to the supplier but would appreciate any advice on anything we could have done to prevent this. i.e should we be re-sealing evry six months or any other specific care?

2. We have some pretty seriously cracked tiles. The main crack seems to run through about five tiles and will sometimes miss a tile and go through the grout and appear on the next tile. We are going to have to dig them out and replace but I want to know how to try and stop it happening again. The cracks do not follow the joints in the plywood underneath.

Both of these probelsm did not appear until the end of last summer (the underfloor heating had been switched off since April)

The floor is constructed as follows.
1. 70mm solid insulation between the joists.
2. loose ply tray
3. 15mm biscuit screed up to the top of the joists with the hot water underfloor heating pipes
4. 18mm ply screwed every 100mm joints are staggered
5. I believe pva was then used and then flexible adhesive
6. A sealant was then applied and excess removed.

Any advice would be appreciated.

I will try and post pictures if I can work out how to do it.

Thanks in advance

 

[TilingLogistics]

There are a few things that are of concern here! The first is the potholling as you call it.

Is that restricted to one area or all over?
Secondly the cracks are there any chances of getting better pictures posted please? you can email me direct or post on here!
If I am reading correct the UFH was laid and then it was overplyed with 18mm ply and then PVA'd!!! Have I read that right?
Is the substrate the same underneath all the way through the installation?
Was the Travertine pre filled or grouted on site after installation?
What size are the tiles?
How many M2 is the total installation?
Where are you in the country please?

Kevin Martin

 

[basshunter]

Looks like it could be inadequate coverage/lack of back buttering in terms of the potholing.The cracks are just showing whats going on underneath.

 

[Branty]

Through the holes, can you see the adhesive, or just more stone. If you can see the adhesive, then the fixer hasn't back buttered the tiles. If its stone, the you have a problem with stone quality. With this stone you have little pockets in the stone, the lower the quality the more holes. In my experience there's not much you can do to avoid this happening.
The more worrying this is the cracking.

 

[grumpygrouter]

Interesting thread for someone like me that has not fixed much in the way of stone and never trav or limestone.

I think I have just come to the desicion that I will use Ditra where ever posible beneath these type of tiles, it may save a lot of problems!!

Grumpy

 

[basshunter]

your right-its expensive stuff so why skimp on the prep

 

[MICK the Tiler]

The PVA primer thing has got me concerned, It does seem to be in favour with some of the fixers around. It SHOULD NOT be used as a primer or admix in glues and grouts because it will break down in the presence of alkaline compounds forming acetic acid not something you want around stone. Could be the cause of the patchy pinholes in random areas of the stone.

The cracking could also be caused by the adhesive coming in contact with the pva or worse being used in the adhesive mix causing the glue to partially fail in some areas and not in others.

At best a simlpe remove and replace and regrout of affected tiles.

At worst a complete stone floor failure and I think you might know what comes next.