Limestone tiles colour change

[Jagweb]

Hi, I have recently had Jerusalem Light Limestone tiles installed over a brand new wet underfloor heating system laid on the original floor (concrete over 10 years old). A decoupling mat was put down first. The appearance has significantly changed during the process of laying including severe cloudy patches. What could have caused this?

 

[Spare Tool]

Seems to be a reoccurring issue with limestone at the moment, not leaving them long enough to completely dry out seems to be the issue, notice yours are grouted so must have been sealed now trapping in the moisture I'd presume..

 

[Jagweb]

Seems to be a reoccurring issue with limestone at the moment, not leaving them long enough to completely dry out seems to be the issue, notice yours are grouted so must have been sealed now trapping in the moisture I'd presume..

Just wondered what happens during the laying process that makes the moisture darken the tiles?

 

[Spare Tool]

The 6 litres of water mixed in with every bag of adhesive has to go somewhere, and as you've got an uncoupling mat down only place is up and out through the stone..

 

[Dumbo]

Moisture . . . .

 

[J Sid]

Also most of these tiles are stored outside, even if the pallet has plastic around it it will sweat and the stone will take in a lot of moisture. That all need weeks of drying time after being layed before sealing and grout. Customers need to be patient, most out there sadly don't want to wait and then they end up with this.

 

[Jagweb]

Also most of these tiles are stored outside, even if the pallet has plastic around it it will sweat and the stone will take in a lot of moisture. That all need weeks of drying time after being layed before sealing and grout. Customers need to be patient, most out there sadly don't want to wait and then they end up with this.

Thanks for all the comments. So... if they are now sealed/grouted/sealed, will they ever dry out or is the colouring permanent?
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The 6 litres of water mixed in with every bag of adhesive has to go somewhere, and as you've got an uncoupling mat down only place is up and out through the stone..

thanks for the comments. The adhesive that was used was Tilemaster Adhesives Ultimate Grey C2 F S2 20kg. This is supposed to be rapid set - would moisture from the mix still have caused this do you think?

 

[J Sid]

I would expect over the coming months the tiles to lighten,

 

[Dougs Third Go]

they will dry out eventually but my guess is it will take quite a long time as the only evaporation egress will be through the grout joints, unless they were sealed too

 

[Tiler Durden]

Why did you use Grey Adhesive? Should be white.

 

[Unused Account 1]

If its limestone ,should of been white adhesive ,watch out for shadowing ,porous tiles ,

 

[J Sid]

Well spotted... . . .

 

[Bill]

Grey adhesive will not always discolour limestone........ before adhesive, limestone was fixed in sand and cement and that was hardly ever white!

Some limestones are more porous than others so you probably just need to wait.

 

[Dumbo]

If we're going to pick on adhesive , shouldn't of used s2 on dural

 

[J Sid]

Jerry, didn't someone post on here that dural recommend S2? Read it somewhere
But I agree wouldn't use a S2 on mat.

 

[Dumbo]

Jerry, didn't someone post on here that dural recommend S2? Read it somewhere
But I agree wouldn't use a S2 on mat.

I never do , no failures yet

 

[Jagweb]

Why did you use Grey Adhesive? Should be white.
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If its limestone ,should of been white adhesive ,watch out for shadowing ,porous tiles ,

If the adhesive caused the clouding is that permanent? Will they dry out or does the sealant need to come off? Is there any hope they will go back to the original colour or will they need to come up? Have ready about leeching in limestone?

If we're going to pick on adhesive , shouldn't of used s2 on dural

Why would you not use an S2 on dural?

 

[J Sid]

The grey adhesive would not normally stain the stone.
Will it dry out and return to original colour, should do a bit over time.
If you a S2 on plastic uncoupling membrane the S2 sticks to the mat. These mats work by the adhesive locking into to mat and not sticking to them.

 

[Lithofin BOB]

you could strip one tile in a discreet area, trapped moisture can lead to water marking which can be irreversible . If the one tile lightens over a few days or you place heat over it to see if it lightens. strip the rest and re seal once the floor regains the colour.

Sealers can highlight colour too, test on an un laid tile, seal it - no moisture involved, if it darkens, could be your sealer showing natural Colours , poss change to a water based ,which may not change the colour

 

[Spare Tool]

Yey Lithuanian Bob's back. . .

 

[Flintstone]

What brand of sealer was used ? As they don't all trap moisture ..

 

[Lithofin BOB]

Yey Lithuanian Bob's back. . .

New pad, can’t work this
New forum can’t work this either
May take a bit of time
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Sealers , impregnators ,state breathable \ to a degree!!!!!

 

[J Sid]

Evening Bob, hope your well.
Yes a few changes

 

[Jagweb]

What brand of sealer was used ? As they don't all trap moisture ..

It was this one....? It wasnt buffed and mutiple coats were aplied on the same day. Also have been told today the expansion joints weren't necessary (on a decoupling mat and over underfloor heating but the screed under all that is 10 years old), the grout is too fine (powdery prob wall grout) and the whole lot needs to come up and be replaced.

 

[Flintstone]

That looks pretty terrible workmanship.