Laying Limestone Tiles

[jane123]

Need help from an expert tiler - we have just bought some limestone polished floor tiles - these have been laid on 2 different surfaces - one section is plywood and the other is screed - however, the screed was approx 20-25mm lower than the plywood (kitchen has been extended). The tiles have been laid with flexible white adhesive on the plywood whereas the builder has used sand and cement mix on the screed to raise the height of the floor in line with the tiles on the ply. There is a noticeable difference in colour and patterns on the tiles in the 2 areas. We are thinking that our only 2 options are to take the tiles out (in the sand and cement section) and with re-screed to raise the level of the floor or to use granfix pourable thickbed as someone has suggested by someone - what woud you suggest - the tiles are beige moleanos polished limestone - they are lovely - we are prepared to pay out to buy more tiles but are concerned that the sand/cement have distorted the colour of the tiles and are not stonr genought to support the tiles - but we have to raise the height of the floor (where the screed is) - basically we have extended our kitchen - old kitchen has ply and new area has screed - please help !!!

 

[faithhealer]

welcome to the forum Jane, I'm sure someone with experience of this will be along shortly, how long have the tiles been down and I'm sure someone will ask for pictures if you have any

 

[hillhead]

sounds like the screed should have been brought up with a suitable backer board or heavy ply then floors all level and a suitable adhesive like keraquick white used all over.

 

[Aston]

i would have used either schluter ditra or durabase over the 2 different substrates after balancing the difference in depths of the substrates that way you would have eliviated the shading issues ...

 

[DHTiling]

Hi Jane and welcome..

Moleanos is very nice as you say.. It will more than likely have been stained from the cement used in the mix..it is advisable to use a white adhesive and back skim the tiles to achieve a regular shading.

There are slight shading with limestones but that is common with natural stones.

20-25mm will need a suitable screeding compound to go that thin.. and as mention above i too personally would have uncoupled the tiles from the substrate to lessen the chance of lateral stress cracks.
If there is any slight deflection where the 2 substrates meet then you will get cracking at this point and normally a movement joint is inserted at this junction.

A products are available to use to raise the floor height enough to bring it back in line with the timber side.

Maybe a pic of what you have will help us see the shading.

 

[mikethetile]

:welcome:

 

[White Room]

How long before the tiles were laid was the screed allowed to dry

 

[The D]

How long before the tiles were laid was the screed allowed to dry

i think it was set in sand and cement

 

[The D]

Incorrect installation from the builder IMO if he had used a sealer on the reveres side of the stone there would have been no staining. With the situation as it is I have to agree with the above comments screed to align the sub straights then an uncoupling membrane.

 

[Time's Ran Out]

Incorrect installation from the builder IMO if he had used a sealer on the reveres side of the stone there would have been no staining.

What sealer would you have used on the reverse side of the stone?

 

[jane123]

Hi there
Thanks for the advice

I will post a picture in a little while. Since posting last night one of the tiles has cracked and broken off at the corner and 2 other tiles are moving.

We have decided to remove the tiles that have been sand and cemented and put a new layer of screed to make the floors the same level - we are considering using mapei topchem so that the screeds doesn't take as long to dry. The previous screed was left 3-4 weeks so I am confident that this was dry enough to tile and the issue was created by using the grey sand and cement rather than white adhesive.

My question is what product/job needs to be done to merge the 2 substrates, i.e the plywood and the screed? Once the screed has dried we will definately use white adhesive and make sure the tiler butters the tiles.

Thanks.

 

[david campbell]

can't say much more than dave has added,and i would have levelled it off with a suitable backer board or ply