Moleanos Tiles Looking Stained afterfitting 6 weeks ago

[ronron]

Hi,

I have had a builder fit my two bathrooms with Moleanos White sandstone tiles onto "Wedi Boards". Tiles are 10mm thick

After 6 weeks, heating on for 4 weeks, extra heaters for a week and now a de-humidifier for 3 days the tiles still look asif they are drying out but i think they are stained, see the photos.

Any advice on what the problem could be?

 

[wayne]

Can't say for sure but looks like the tiles have been dot and dabbed and not back skimmed. Where it's dark is where the adhesive has bled through. Back skimming the tile would have probably solved this

 

[ronron]

Hi Wayne,
Thanks, do you think if the wrong colour of adhesive was used i.e. grey instead of white, would also cause the staining with it bleeding through?
Ron

 

[MARBLE_TONY]

Wayne right on the money I think. Also what colour adhesive was used?

 

[ronron]

Hi Tony,
The builder says it was white but my wife said she saw adhesive in the bucket that was grey?, so i think i will need to get a few tiles off to see as it is hard to tell through the gaps (Grouting not yet done)

i suspect he has used grey and it has bled through as Wayne has suggested

Thanks
Ron

 

[dave l and l]

check the adhesive that is round the pipe work in the pic that might tell you if its white or grey from the pic it looks white but that could be deceiving

 

[DHTiling]

Was the adhesive a slow set one..?.. this will allow more moisture to ingress back into the tile as it does not hydrate quick enough to prevent wetting through the tile... most look fully bedded but as mentioned the back buttering has not fully covered the tile backs hence the uneven wetting marks.. normally you trowel the walls and back blade the tile to bed, this in turn will be even colour change of tiles if effected by moisture.. but moisture sensitive stone should be fixed with a suitable rapid setting adhesive to minimise this staining..

Just to say the wetting you have there might dry out once the tile expels all the moisture within it...

 

[Dontiler]

Hello and welcome
do you know if your tiles been sealed?
if so I would recommend stripping sealer of as it will help for moisture
evaporate, wouldn't recommend stripping tiles off yet,
you might find out that tiles will dry out and will look as they should,
At the moment all moisture is trapped behinde the sealer,
So if your tiles been sealed, strip off sealer with something like stain away
And leave it to dry for another week or 2
good luck

 

[ronron]

Thanks everybody for your input, as far as i know the sealer has not been applied and after 4 days of having a dehumidifier all that has happened is that my bathroom walls have dried out and split and my bathroom door has warpped so much that it will not close......

Does "Back Skimmed and Back Bladed" mean the same thing?, anybody got a phot of how that should look?

I have a meeting with the builder, the stone supplier and adhesive supplier tomorrow to try and resolve the issue so any more information would be a great help.

Thanks Ron

 

[Pebbs]

The stone is drying out, it can take up to six weeks, did no one tell you that? I don't see any issue at the moment, and the photo that shows the adhesive clearly shows its white. Have a little patience and let the stone dry out before pulling 3 people in, when the stone isn't even dry yet.

Pebbs

 

[ronron]

Hi Pebbs, thanks for your feedback, the tiles have now been up 8 weeks, we have had the heating on for 6 weeks, extra heaters in the bathrooms and dehumidifiers, the walls were so hot you could not touch them, yet the marks never changed from what you see now to what was there 7 weeks ago, so i can't believe they are still drying out?

 

[DHTiling]

Ok.. if that is the case then i am inclined to think they are stained ... you will need a meeting with said individuals and discuss the next step and rectifying the situation.

 

[Dan]

As Dave says. Seems they're stained too much time has passed for them to still be holding moisture.

 

[ronron]

Hi Dave,
Meeting everybody today and i think the plan is to take some tiles off, have a look and also send the tiles and adhesive off for testing......

Question, can white adhesive cause this type of staining?

 

[DHTiling]

Not normally but with certain stones, then you must use an adhesive that is suitable for stone use and of a rapid setting type... this will not let moisture ingress for a prolonged time thus causing what you have there...

I can't see what tests they think will help.. imo it is purely wrong adhesive for stone type..moisture sensitive stones require rapid sets.. just my opinion though, so see what they come up with.

 

[Pebbs]

Im following this one with interest, be interesting to find out what their views are at the end. Moleanos does have a long drying out time, but this is only 10mm, Ron what brand of adhesive was it?

Pebbs

 

[ronron]

Hi Pebbs, i have been told that the adhesive used was WEBER Set Plus White, i don't know if that is a rapid setting adhesive or not. Going by Dave's comments above, would WEBER Set Plus White cause this staining?

 

[Pebbs]

Sorry for the late response Ron, yet again I have been run ragged. I've put thousands of m2 of moleanos down on diff contracts and have never seen a white adhesive stain through, but I never specify Weber, so am not au-fait with the complete range. Has there been any change at all on the stone?

Pebbs

 

[ronron]

Hi Pebbs, thanks.
Still no change, the stains are still there, i suspect that they have not used fast setting adhesive, but i am not a tiller so waiting back to see what the results are that were taken away for testing
ron

 

[lucius]

Weber set plus is not a rapid and only sutiable for medium porosity stone.

 

[Dan]

So perhaps that IS the problem there then?

 

[ronron]

Many thanks for your input, will let you know thew outcome once i speak to everybody.

Ron

 

[ronron]

Weber set plus is not a rapid and only sutiable for medium porosity stone.

Thanks Lucius, Does anybody know what the perosity is for Moleanos White Stone Tiles? is it Low, Medium or High perosity?
Ron

 

[jonnyc]

Just picked this thread up.like Pemba I have fixed thousands of mts moleanos over the years.
a number of good points have been made but I will repeat what I have found from my experience as not only a stone fixer but also stone restorer.
i have seen this patchiness many times.it is far more common when stone fixed with non rapid flexible adhesive.
the moisture migrates through stone bringing minerals from stone and polymer from adhesive to surface of stone. Water Moisture evaporates and leaves a stain on surface of tile.this has a slightly furry feel when compared to the surface of an unfixed tile.provided that all the moisture has worked its way out which I'm sure it will have by now,I would get a tin of lithofin wexa cleaner..mix a bit of wexa a 1:5 with water .apply with a sponge,keep wet ,don't let it dry in .scrub with bit of nylon pad and wash off.take a hair dryer and dry the cleaned part.best to try to halves of two different tiles to compare against a half not cleaned.
this works virtually every time.
rapid set adhesive should have been used as it would prevent this migration through stone as rapid set pulls moisure within itself.
i used to get a problem like this probably 15 years ago,when no one really understood about having to use rapid set.
I was using Ardex x7 slowset and ardion 90.i would solid bed stone but get a horrible yellowish stain all over tile.it would take as long to get rid of staining as laying the floor.
eventually I tried many different adhesives until I found weber stone set range.they had a slow set which by luck more than design did not stain stone.
i worked closely with weber rep and their chemists on this.
i then changed again when needed stone to dry quicker and now only use rapid.
The dark patches on your stone are where back of tile is in contact with adhesive.
the light parts are where there is no adhesive connected to back of stone and voids.
this patchiness is not seen on most limestones when you fix with slow set flexible.
its mainly moleanos,Turkish porous white ,apple stone and other solar stones.
give wexa a try. Would be interested to know if it works orm by all means call me

 

[jonnyc]

Sorry last sentence was meant to read,patchiness does not normally occurr with rapid flex