External tiling onto a new concrete slab

[llevram]

Hello all, I have a job coming up to install 20mm thick porcelain large format tiles onto a freshly laid concrete slab (once cured)

Looking for some advice on the following....

1. How long from the day the concrete is poured until you can tile ?

2. I've done this many times in Australia but as climate and weather is a lot different here I can only assume the prep work must be too.... what's the method for sealing the slab?
As in what primer/waterproofing agent do people use in England than coinsides with the English climate?

3. Any other advice anyone's willing to add would be very much appreciated.

Thanks in advance

 

[LM]

Our guidelines are 6 weeks for a 100mm slab at 20 degrees Celsius as an average.
The surface should be abraided by scrabbling etc to remove the laitanance.
With our climate you should factor in dispersion of water with the inclusion of a system such as Schluter Ditra Drain 8 etc.
An on site specification from your adhesive supplier would be advisable for this project, most reputable manufacturers will provide this for free.

 

[llevram]

Cheers for your advice.

The concrete slab has aco drains around the outside which is connected to a soak away.

Would you recommend a liquid Dpm to be applied to the slab before
Tiling?

Also can SLC be applied over the top of the dpm or does that have to be applied first?

Thanks

Our guidelines are 6 weeks for a 100mm slab at 20 degrees Celsius as an average.
The surface should be abraided by scrabbling etc to remove the laitanance.
With our climate you should factor in dispersion of water with the inclusion of a system such as Schluter Ditra Drain 8 etc.
An on site specification from your adhesive supplier would be advisable for this project, most reputable manufacturers will provide this for free.

 

[Tommythetiler80]

Hi , just Done a job where I black jacked dpm a concrete base and SLC over the top so it is fine to do. Just mix dpm 6:1 for a primer base then a neat coat over that . Then before SLC prime with a sbr first coat 3:1 then follow with a neat coat. Always Advisable to call techies for whatever products you may use though.

 

[Tommythetiler80]

 

[Old Mod]

I black jacked dpm a concrete base and SLC over the top


Then before SLC prime with a sbr first coat 3:1 then follow with a neat coat.

What slc did you use Tommy?

 

[Dumbo]

You would need an exterior grade latex such as ardex k301

 

[hmtiling]

Ditra drain or use the pedestals for me. Bal acrybase and rocatex xl500 are a couple more external grade levellers.

 

[Old Mod]

You would need an exterior grade latex such as ardex k301

Yeah cheers JC, I know what I would use, just curious as to what Tommy did.
Thanks.

 

[hmtiling]

https://www.tilefixdirect.com/category/pedestals

 

[hmtiling]

Tommy's looks indoors to me.
I've thrice posted that link for some reason

 

[Old Mod]

I've thrice posted that link for some reason

That's cos you're a plonker 'Rodney'

 

[WetSaw]

Surely you don't want to use SLC on an exterior slab because you don't want it level or am I missing something?

 

[Dumbo]

Surely you don't want to use SLC on an exterior slab because you don't want it level or am I missing something?

I put levelling comp on an external slab because it was really uneven but still maintained a fall .

 

[Tommythetiler80]

What slc did you use Tommy?

Went with levelFlex from Tilemaster

 

[Tommythetiler80]

Tommy's looks indoors to me.
I've thrice posted that link for some reason

Yeah was indoors,it was more the fact that I covered over blackjack dpm

 

[Dumbo]

I've always found techies a bit twitchy about going over blackjack or similar as they have said to me in the past there is not enough weight to hold blackjack down and that water pressure even if it is only rising damp will blow it away and they say you need a least three inches of screed .

 

[llevram]

Just spoke to a rep from ardex who claims the concrete slab does not need sealing, priming or any form dpm prior to tiling when using ardex x 77 adhesive.

Thoughts anyone?

 

[Dumbo]

Did he doesn't need priming or do not under any circumstances prime because I would prime unless I am told not to prime and that doesn't include doesn't need .

 

[llevram]

Did he doesn't need priming or do not under any circumstances prime because I would prime unless I am told not to prime and that doesn't include doesn't need .

He said told me no primer or dpm has to be applied to the cured slab prior to tiling

 

[Dumbo]

No primer has to be applied is not the same as saying don't prime . I would get clarification .

 

[llevram]

No primer has to be applied is not the same as saying don't prime . I would get clarification .

How do I get clarification mate ? Cheers

 

[Dumbo]

Ask him are you saying doesn't need priming or are you telling me not to prime because it is detrimental .

 

[Tommythetiler80]

Get him to email you a copy of what he has stated for you to do. That's what I got tilemaster techies to do they obliged with ease.

 

[Dumbo]

Just spoke to ardex . You don't need to but you can

 

[Tommythetiler80]

Yeah cheers JC, I know what I would use, just curious as to what Tommy did.
Thanks.

Hi mate, I was going to use ardex k80 But priced it and was going to be double the price of levelFlex but I spoke to tilemaster gathered the info I needed and went with their product as I'm familiar with it (use it on a daily basis). Also the floor in a couple of months is going to be tiled. Hope that clears your curious mind

 

[Old Mod]

Hope that clears your curious mind

Well not really.....
See, here's the thing, you said you applied a bitumen based dpm over concrete.
Then two coats of sbr and levelled. (In essence)

Now I've always attempted to remove any bitumen based product before any tiling works, including levelling.
But you're saying that it's ok just to prime with sbr when I've always believed you have to apply a mechanical primer, like prime and grip, to bitumen residue, not coating, then level.
So am I misunderstanding you, or am I missing something.
Black Jack to me has always been a bitumen based vinyl tile adhesive.
So this is where my confusion stems from.

 

[Old Mod]

And it mentions nothing about bitumen here, only resin based dpm

 

[Tommythetiler80]

Well , I spoke to tilemaster on the phone and explained what I was planning on doing and they had no hesitation in instructing me what to use before levelling. Maybe I'm wrong then

 

[Old Mod]

Well , I spoke to tilemaster on the phone and explained what I was planning on doing and they had no hesitation in instructing me what to use before levelling. Maybe I'm wrong then

If that's what you were instructed by them, then ok, I know they stand by their word.
I was just trying to clarify it for my own piece of mind, that's all.
Cheers.