Tiling outdoors - the correct method. Discuss!

[mean_in_green]

'Afternoon Gents.

Am back after receiving and implementing some excellent advice on my first visit here.

Our patio needs sorting out at some point, raising and levelling. If I was to get the silly idea of tiling it afterwards, could you give me a steer on the correct "only doing this once" method please?

It's sixteen metres across the rear elevation, extending out by four and a half metres.

I'm not a tiler, but would take advice gratefully and can follow detailed instructions no problem.

In my head so far:

Minimum 150mm wacked hardcore
Minimum 100mm concrete
Membrane
Incorporating an appropriate fall
A retaining perimeter edge of some description (ally angle?)
Non slip!

 

[SJPurdy]

I'm not confident to answer this without going and looking it up myself. But will add the question what movement joints will be required: The patio will be 16m long so I would think that in the UK this should be broken into minimum 2 sections with a movement joints accurately positioned in the concrete slab so that a joint in the tiling will fall directly on top of it. I am basing this on it being heated by the sun for part of day and so maximum length of a heated tiled floor is 8m.

I am also unsure why you need a membrane?

Don't skimp on whacking the hardcore - you need to make sure that this is a firm stable bed to "build" on.

If using large format natural stone outdoor tiles/paving then the process is simplified in that they can be layed directly over the hardcore onto a bed of sand/cement/(+additive).

 

[One Day]

If you're after a fine and dandy looking porcelain job, then please read up on either Schluter's systems or maybe now the new Gutjahr systems from BAL.

Me personally? I'd be happy with a solid concrete base coupled with Ditra-drain under the tiles.
You'll need to put expansion joints in the base, and follow them into the tiles.

Start here: Red Sky Thinking from BAL for fail safe external tiling | BAL Adhesives - http://www.bal-adhesives.com/red-sky-thinking-from-bal-for-fail-safe-external-tiling-2/
and: Balconies and terraces | Schlüter-Systems - http://www.schluter.co.uk/balconies-and-terraces.aspx

 

[Bill]

If using large format natural stone outdoor tiles/paving then the process is simplified in that they can be layed directly over the hardcore onto a bed of sand/cement/(+additive).

So can tiles. And they don't have to be large format.

 

[One Day]

So can tiles. And they don't have to be large format.

I wouldn't do that outside though without drainage in the bed. Wet bed and freeze/thaw is not good news for external tiling.

 

[mean_in_green]

I am also unsure why you need a membrane?

If using large format natural stone outdoor tiles/paving then the process is simplified in that they can be layed directly over the hardcore onto a bed of sand/cement/(+additive).

I was thinking a membrane might be best to help deal with drainage.

Have looked at some natural stone - the stuff we've seen so far wouldn't really suit the property, but the idea of something like trav slabs could work (i.e. +/-30mm thickness). Does that fall into the category of sand / cement fixing then? I hadn't considered that method as a possibility, thanks.

 

[mean_in_green]

Start here: Red Sky Thinking from BAL for fail safe external tiling | BAL Adhesives - http://www.bal-adhesives.com/red-sky-thinking-from-bal-for-fail-safe-external-tiling-2/
and: Balconies and terraces | Schlüter-Systems - http://www.schluter.co.uk/balconies-and-terraces.aspx

Some good reading there, thanks.

Expansion joints - good shout, mirrored through the layers.

 

[widler]

I really wouldn't bother with a matting at all, not sure why it would need one?
I'd lay straight on top of concrete .
Any matting would hold water and freeze, expand and blow your tiles.
You need as much drainage as you can get in external flagging, tiling, etc eat

 

[One Day]

I really wouldn't bother with a matting at all, not sure why it would need one?
I'd lay straight on top of concrete .
Any matting would hold water and freeze, expand and blow your tiles.
You need as much drainage as you can get in external flagging, tiling, etc eat

Sorry Craig you're wrong mate. Drainage matting, designed just to do that-drain. Don't confuse it with ditra or dural etc. Give the links i posted 10 mins of your time and you'll see what i mean...

 

[widler]

read them , don't have a problem with people using them, just seems a waste of time, don't think it needs them to be honest on a outside patio .
Balcony maybe, but thats a completely different senario to a concrete patio

 

[One Day]

For normal stone on a concrete slab I'd normally agree, but customers are getting SO blinkin' fussy with their Italian porcelain and 2mm ivory grout which they moan like mad about if it changes colour in the garden...
I went on the Schluter externals course and had my eyes well opened to the principle of allowing water through the grout and adhesive but then using a method to drain it away fast so it doesn't stay wet.

As a minimum nowadays I'd be asking (maybe not insisting) that I use at least Ditra-drain on a concrete slab.