insulation Quinn therm 50mm in conservetory

[Trevor Harmer]

Hi I'm in the process of laying ufh took up the old tiles to find the screed crumbling away so I have had to removed all the screed back to the concrete base. My dilemma is this. I have got 50mm Quinn therm QL to make up the screed base but this seems to be not so ridged if you kneel on the insulator it leaves your knee print! I will be laying 500x500 tiles what would you suggest laying the ufh over this and self level or add something ells on the insulator before self levelling?

[Dave]

Thats not an insulation i am familar with...!!.

Has it got the cement facing like other brands..?

[Trevor Harmer]

Hi Dave that's the dilemma its not like Marmox Tile Backer Board no cement facing
What do you suggest?

[Dave]

The only info i can find is that it is used under a screed or concrete base and not tile directly to...

try this info>> http://www.ribaproductselector.com/D...223666.pdf?ac=

[Trevor Harmer]

I was thinking of using putting 6mm hardy baker board over this secured with adhesive then ufh and self level?

[Dave]

Are you just trying to build height up or is the insulation your worries..?

[Trevor Harmer]

No I'm worried about bounce or the sl cracking as you lay the tiles. on top of the insulator I've got about 25mm to play with this includes the sl the tiles and adhesive tile thickness is 10mm.

[Dave]

So the 50mm quinn is insulation..?..To tile directly onto this without it bieng fixed in situ is in theory a floating floor and i am worried about the compression issues with it...

What about a 50 mm marmox or wedi stuck down to the substrate..? much better compression ratio's and can be tile directly to...

[Trevor Harmer]

In hindsight 50 mm marmox or wedi would have been spot on but I do not have that option the insulation is already fixed to the substrate I am hoping to resolve this by the morning I appreciate you taking your time on this Dave do you think my suggestion will work in theory putting the hardy backer fixed to the foam is the same as a cement facing
board?

[Dave]

How is the quinn board fastened..?

[Trevor Harmer]

on a SBR base 4to1 wash with sand cement mix and then rapid set flex tile adhesive in other words
well stuck!

[Dave]

OK...Well it's just the compression issue then...if you thinkit will be fine then as i cannot see what you can it's hard for me or others to say yes deffo go ahead....might be best to lay a hardi board on it and then see what compression you have....this thing is with marmox and wedi boards there compression rates are good but seen as i have not come across and seen the quinn then thats hard to advise 100%.

[Dave]

Also thinking about it trevor, how are you going to fix the hardi down..?

[Trevor Harmer]

Thanks Dave for your help as far as I'm aware the compression ratio is as high as marmox
so in theory it should work the other option was to go with just the leveller 2 part latex
but on bouncing this off yourself this is probably not the thing to do!
thanks again
Trevor.

[Dave]

Trevor...In the morning phone a few adhesive tech lines and ask if they have a slc that will cope on top of the quinn board..hardi is normally glued and screwed, so again get confirmation on this option..

Last thing you want is a failure and this is a scenario i have not come across...good luck mate...let us know the outcome plz.

[Ajax123]

Quintherm is as far as I know a standard 350Kpa polyurethane rigid board similar to Kingspan or Celotex but it does not normally have a foil backing which makes it a bit prone to point load compressions e.g. when you kneel on it. The other PU boards do this as well but it is not usually so noticalble cos the foil back holds it a bit more rigid.

Not sure about the SLC or other stuff though I have only ever seen it used where a screed is put over the top when the impressions don't matter too much.

Can't imagine SLC and tiles direct to the board being very succesful though. What sort of overall depth have you got available over the insulation

[Trevor Harmer]

Thanks Ajax and Dave.
went with the original plan. SBR base 4to1 wash with sand cement mix and then rapid set flex tile adhesive to the Quinntherm. 6mm Hardi backer board on top fixed with standard set tile adhesive solid as a rock. laid my ufh and the SLC to go over tomorrow.
this base feels very strong and ridgid now I have the 15mm to play with for my tiles
Happy Days
Thanks for you advice guys.

[Trevor Harmer]

Hi Guys thanks for your advice i have finished the job and with great success the customer was very happy that he didn't have to Waite months for a screed to go off
this system worked very well and I will try and post some photos of the project
Trev.

[Dave]

pics would be good...