Sealing Moleanos Beige

[mattw2]

Hi - wondered whether anyone had any advice on laying & sealing a limestone floor? The stone details are:


Name of stone: Gasgoigne Beige Limestone
Type of stone: I believe that this is actually a Portuguese Moleanos Beige Limestone
Size of Tiles: 900mm x 600mm x 12.5mm
Edge: Sawn
Finish: Honed
Area: largest continuous area, c.40m2
UFH: Wet

GASCOIGNE MOLEANOS BEIGE LIMESTONE TILES & STONE

My tilers have done a beautiful job on the porcelain tiles in the bathroom, but seem a little nervous about the limestone floor so thought I would see if I get some suggestions from the experts on here on which sealants, number of coats, and any other tips you could share.

Thanks

Matt

 

[DHTiling]

Sealers choice gold.or LTP matt stone..2 coats...

 

[Ajax123]

Assume as wet UFH it is over a screed of some sort. Does 40m2 of this type of stone need to be jointed

 

[mattw2]

It is a sand cement screed - couldn't tell you the mix though - was laid near end of November. UFH has been off/on gradually for past 10 days.

 

[Ajax123]

Is the UFH all one zone or is it split into separate zones?

 

[mattw2]

One zone, 2 loops - was designed by the UFH supplier, Timoleon. Out of curiousity, what difference does it make if it one or two zones?

 

[Ajax123]

If two zones there should be a isolation joint in the screed berween zones due to differential expansion and contraction under heating at different tempratures. As 2 loops one zone should be no need to joint although 40m2 is right at the top end of the safe size for s/c screeds. Any defficiencies will most likely show up under the commissioning so if no cracks appear you can assume reasonably safe. Trouble with lots of natural stone tiles is that they are relatively soft due to natural flaws and grain patterns in the tiles. If the screed cracks underneath it can crack them. Sand cement can curl and shrink long term so I would tend to suggest itra or similar under natural stone in this type of substrate where areas exceed about 15m2 based on NHBC guides (Not same as British Standard recomendations). I not a tiler though so maybe more advice from pro tilers will be helpfull.

 

[Richardk]

LTP Mattstone for me, at least 2 coats. I'd hope that Ditra or similar was used.
Also, "Area: largest continuous area, c.40m2" suggests possible other areas off the main area. If so, movement joints should have been installed. UFH should be commissioned properly.

 

[mattw2]

Thanks for those suggestions on sealing Richard & Dave. Was curious that Lithofin Stainstop wasn't the choice - any particular reason, or is it just experience that the others work better on this stone?

The supplier felt that ditra wouldn't be necessary on the basis that the screed would have had over 7 weeks to cure, with 4 weeks of UFH running (increasing temp up to operating temp over 2 weeks I think) - that make sense?

The screed was laid over two days and a narrow (less than 0.5mm) crack has appeared along the join of the two sections - is this something to worry about?

What I meant by "Area: largest continuous area, c.40m2" was the entire area on one level - there is a smaller section of c.8m2 that you have to step down 8" to go onto. The main area is 8m x 5m. There is expansion joint all the way round the edge.

 

[DHTiling]

Stainstop is fine and i used to use it a lot...but as time progressed i have moved on..