Can it be done? Are my slabs too big! Help! - TilersForums.com

[g cambrensis]

Want to lay sandstone slabs various sizes 300x300 upto 900x600 over ufh.
Screed was a liquid pour type and these slabs are uncalibrated 25-45mm in thickness.

I know i'm going to need a lot of flex adh to pack up but is it do-able? Last tiler came out and said it wasn't.

I know of an adh called nocros 'thick bed stone and porcelain adhesive'. Would this do the job for fixing? Any help appreciated.

Thanks

 

[jay]

Re: Can it be done? Are my slabs too big!

hi the variation in thickness might challenge you can it be sorted so you start off at 45mm then as you neer end lay 25mm slabs :8:if you can grade it i cant see why it cant be done just remember your finish height

 

[jay]

Re: Can it be done? Are my slabs too big!

forgot to ask whats the sub:8:

 

[heavytrevy]

Re: Can it be done? Are my slabs too big!

You will need to wet bed those big slabs.
Totally doable but u will need somebody specailised in stonework.

Goodluck in finding somebody suitable.

Trev

 

[g cambrensis]

Re: Can it be done? Are my slabs too big!

forgot to ask whats the sub

Sorry, your dealing with a novice! Subfloor?
Liquid screed was poured on to a depth of between 40-50 mm

The 2 guys i've spoken to so far are putting a downer on the whole thing and i need some advice.

Some have told me to use sand-cement rather than nocros flex adh. Whats the opinion on that?

Other question: where do i find people? A lot aren't used to laying large uncalibrated slabs indoors. Should it be that big a deal finding a layer.

Ultimate question! Can i do it myself? (with enough advice from you lot)

 

[heavytrevy]

Re: Can it be done? Are my slabs too big!

yes u will need mortar (sand, cement) for the wet bed.
You will have to create a screed /wet bed and lay ur slabs onto it when wet , tap into place to level and acheive the desired height.


Its a job for a stonemason or large format specialist.
very few tilers can wet bed nowadays .

Trev

 

[Gazzer]

Re: Can it be done? Are my slabs too big!

Thoughts that i am having here are. You say that the thickest slab is about 45mm , so we assume that even if you used an adhesive to lay these with you would have at least 50mm from the sub floor. I assume the UFH is a wet system which wil be about 10mm below the screed, maybe more !. It seems a lot of tile for the heat to come through in my mind. I could be wrong as i have never done such a job as this.

 

[jay]

Re: Can it be done? Are my slabs too big!

as above still wondering on sub concrete or timber can it be graded :8:

 

[g cambrensis]

Re: Can it be done? Are my slabs too big!

yes u will need mortar (sand, cement) for the wet bed.
You will have to create a screed /wet bed and lay ur slabs onto it when wet , tap into place to level and acheive the desired height.

I wanted opinions on this as i was also told that any fixing agent needed to be flexible as the expansion and contraction of ufh would lead to cracks and a lot of heartache.

Took advice from uponor for ufh. Upto 100mm is acceptable but there is a time lag on the warmth.

Jay - at the risk of sounding stupid whats the sub concrete?
Liquid screed was pumped in. Now totally flat.

I had a tiler lined up, and waited for him but he's more or less walked off and i'm left with 80 odd Sq M to lay.

Thanks all

 

[heavytrevy]

Re: Can it be done? Are my slabs too big!

I doubt you will find any fexible adhesive that can be bed up 35mm WITHOUT failing.
Im recomending a wetbed of atleast 50mm reinforced with poultry mesh.

Trev