Tiling over insulation sheets

[DHTiling]

I don't think the slc was suitable for installation over that type of board......

1: Is the board the type that is soley poly core and no cement facing to it.

2: I also don't see any expansion at the edges to the wall.?

 

[countryboy]

Hi dave,
The boards have no cement facing.
What type of SLC do you think would work ?
Not sure what you mean about expansion edges ?

 

[White Room]

Are they just a dense foam

 

[DHTiling]

Did you prime the boards...?


By expansion i mean a perimeter gap around the external edges of the floor.

 

[countryboy]

They are a compressed foam.
They were not primed, the vendor (Warmsoles) gave no instructions about priming.
I get the expansion edges, but never knew they were necessary.
Are they a must ?

 

[Daz]

They are a compressed foam.
They were not primed, the vendor (Warmsoles) gave no instructions about priming.
I get the expansion edges, but never knew they were necessary.
Are they a must ?

You need to check the Arditex bag, but from memory I think it does advise that the substrate should be primed prior to laying the slc. As well as sealing, this prevents the slc from curing too fast which can, obviously, cause shrinkage and cracking :mad2:. I'll be using Arditex NA over thermo boards tomorrow, so will check the specs and can advise tomorrow evening, if you like??

 

[countryboy]

Thanks Captain Slow. Any advice at all is very welcome right now.
I managed to find one of the Arditex bags & have attached a photo.
It does mention about priming. I guess the foam would be porous so that could be where the problem lies, too much suction and therefore cracking.
What I really need to know now is : Is there any solution/remedy ?
Or will I have to take up the SLC and pray to God I don't damage the UFH.
Any advice at all is most welcome.
Also attached is a photo of some of the discolouration & cracking together.

 

[jay]

hi looking at photos looks like you may have used too much water when mixing causing it to go yellow and lift check directions on bag norm is between 4.2 and 5 litres per 20 kg bag hope this helpes priming also helpes :8:

 

[countryboy]

:mad2::mad2: Howdy lads, Ive cut my losses and pulled it all up. Thankfullly the UFH wire came away from the SLC undamaged. At least using the loose cable had some advantage. If I had used the UFH mats I would have been screwed. The reason for the cracking was the insulation sheets had come away from the subfloor.
Right now I'm down the cost of the insulation and the SLC.
Next step is to prime the concrete subfloor and re-lay the UFH. From there it's just more SLC.
A serious thanks to all who have tried to help. I've definately learned my lesson.:hurray:
My word of advice to you is never to use those insulation sheets and pay that bit extra to get the tilebacker boards (cement facing).

 

[DHTiling]

Just a quick question..i know it's too late now...

You used arditex slc...Now i thought Arditex was a 2 part SLC and you do not use water..just latex liquid and the powder...

Can you confirm if it was a 2 part mix and maybe you were not sold the right package..?

 

[Daz]

......The Arditex RS plus powder was mixed with the RS plus latex and poured directly on to the UFH and isulation foam.
......

It looks as though the slc was sold and mixed correctly Dave. I'd hazard a guess that the cracks were due to the insulation boards not being stuck to the sub-floor. Too much movement / flex??

 

[DHTiling]

didn't see that....:smilewinkgrin:...so i wonder why he has a change in slc colour...????

No worries all pulled up now..

 

[Ajax123]

Those cracks look like the SLC shrunk and curled. on unprimed foam boards I guess would have dried very quickly - that would cause both phenomena

 

[jay]

the color is due to too much liquid in mix making it to wet normally:8:

 

[countryboy]

:8:I can confirm the 2 part mix of powder & latex (not water).
2 possiblilties/reasons for cracks : 1 = foam not bonded to floor
2 = foam not primed for the SLC.
Ah well. Life goes on.