Exterior patio help

[Tiler al]

Hi,I need some advice on a exterior patio I have been asked to tile.I have been tiling for approx 3 & half years & have undertaken a lot of interior floors but not outside.The slab to tile on is approx 15 sq meters & is a rapid set fibre based screed which has been down for 4 months & the tiles are 900/450mm by 20mm thick porcelain.My thought process at the moment is to prime with bal primer & the adhesive to use would be bal flex fibre plus as is semi rapid & allows for up to 20mm depth.I would be using a 15mm round notched trowel & back buttering.My questions to you are would you see this as the correct methods & materials for external & would you use a anti fracture mat or is it not needed.I forgot to add that the screed is very flat & has the correct fall on it.Thank you for any help given,I have been lurking on this forum for a while now & it has been a fantastic help to me with the extensive knowledge given out.

 

[J Sid]

I would be looking at bal flex one
The fibre flex plus is a topps only one I believe, maybe wrong. If it is you know its going to cost you.
But yes prime, and no need for uncoupling imo.

 

[Just Rizzle]

i would cover the area to tile in bal flex bone then with there bal flex adhesive stick down your tiles. see bals web site on there flex bone

 

[J Sid]

Why would you use bal flex one Ray?
And which flex one are you referring to?

 

[hmtiling]

If a membrane is going to be used externally then it should be ditra drain imo. I spec it for all my external work
I'm not sure flex bone is even suitable for external use

 

[Dumbo]

I'm with harry , is nobody concerned about frost lift . Ditra drain 8 is my favoured approach
Just done a patio with adpeds but it is a 25 mm build up approx .

 

[Tile Fix Direct Marketing]

I don't think BAL Flexbone can be used externally, we've just started stocking Kerakoll Green-Pro which can be used outdoors.

 

[J Sid]

Max tile and bed thickness for this product please

 

[Dumbo]

I don't think BAL Flexbone can be used externally, we've just started stocking Kerakoll Green-Pro which can be used outdoors.

But is it a drainage membrane , dural ci can be used outside but it doesn't do the same job as ditra drain 8

 

[Tile Fix Direct Marketing]

But is it a drainage membrane , dural ci can be used outside but it doesn't do the same job as ditra drain 8

No that's true, but if the slab has falls do you need drainage membrane?

 

[J Sid]

And a answer for me please @Tile Fix Direct Marketing

 

[Dumbo]

No that's true, but if the slab has falls do you need drainage membrane?

Ditra drain 8 needs a fall for the water to move through , if you apply your logic to a wet room You would say the floor doesn't need tanking as the water will just run down the drain.

 

[Tile Fix Direct Marketing]

Max tile and bed thickness for this product please

There are no restrictions to tile size or thickness with Green-Pro mat.

Kerakoll recommend BioGel Revolution rapid set adhesive - maximum bed thickness of 15mm compressed. If you need to build up more than 15mm beneath the mat then they would recommend a screed or levelling compound before starting.

Hope that helps

Ditra drain 8 needs a fall for the water to move through , if you apply your logic to a wet room You would say the floor doesn't need tanking as the water will just run down the drain.

Good point!

 

[J Sid]

Thanks for that, 15mm is a lot. Bal and I believe schluter are max 5mm

 

[Tiler al]

Thanks for all replies,much appreciated.I will be using a membrane.I will be starting this job on Friday as it's an add on been asked to do do after completing 2 bathrooms & a large floor & would like to get done asap.Would dural be sufficient with a bal adhesive as bal state there adhesive when set can withstand up to -30.Probably a stupid question but is the membrane outside mainly due to the adhesive in freezing conditions as patios have been laid without a membrane for many a year without issues.I have been looking at the adped method for future reference & can't quite work out how that's different to dot & dab,is it purely the thickness of the slab that will stop it cracking.Thanks again.

 

[Dumbo]

Dural doesn't drain so you can get issues with frost lift.
Adped system tiles need to be 20 mm . In this instance your spacing would probably have to be 450 .

 

[Italy]

@JulianSidney

http://products.kerakoll.com/gestione/immagini/prodotti/Green-Pro%20UK%202018.pdf

ready, I trust only the technical sheets
the thickness is not specified, but check the wetting yes
and avoid high adhesive thicknesses.
a few times I used it, I used 7 / 8mm.
on the substrate of sand and cement quite rough.

 

[J Sid]

Bal

Schluter say

There is no maximum limit to the tile/stone thickness that can be installed above Schlüter®-DITRA-DRAIN, providing the thin bed adhesive method is used to bond the tile/stone covering. The minimum tile/stonethickness above Schlüter®-DITRA-DRAIN is 8 mm.

With the thin bed adhesive method, the maximum adhesive bed above Schlüter®-DITRA-DRAIN is 10 mm.

 

[Just Rizzle]

I'm with harry , is nobody concerned about frost lift . Ditra drain 8 is my favoured approach
Just done a patio with adpeds but it is a 25 mm build up approx .

yes frost could be a problem in winter as bal flex bone is a non adhered membrain and breathable in my view most suited but will check with rep.
you can always add frost proofer to your addy

 

[Dumbo]

Frost lift is where you get a pocket of water that freezes and expands . No amount of frost proofer is going to help that.

 

[Unused Account 1]

Ive done two 150 metre outside areas on a screed,just primed and tiled .,that was 2 years ago ,no problems

 

[Joshjupp]

Ive done two 150 metre outside areas on a screed,just primed and tiled .,that was 2 years ago ,no problems

Same here we just primed and tiled good solid bed of adhesive no issues either the base had been down a long time no cracking so just tiled straight to it