Oversite Depth - tile adhesive and screed thickness?

[trustiling]

Have you used Kerakoll? You mix it with sand, and can be tiled on the next day

 

[Ziggy1979]

Hi Guys thanks again.

Can the Keracoll be mixed on site and applied like a traditional screed? Would we use it inside and out?

We've been rcommended a screeder(?) who does sand cement screed and were told he's really reasonable and good. So ideally we'd like to use him but it means no liquid/anhydride etc screeds I guess. We were also told it would be a lot cheaper and as always £matters. 🙁. Is there any reason to avoid traditional screed? Can drying time of normal screed also be reduced with additives?

Outside, can you tile straight onto the outside concrete slab or do u need some form of screed over it? We need to have a fall from the back if the house to the back end of the terrace (4500mm). If we did go with a liquid screed would it not 'self level' and lose the fall?

Thanks again for all your help. 🙂

 

[widler]

Yes you can tile straight onto outside concrete, as long as its nice and flat [emoji15]
Nothing up with traditional screeds ,they have been tiled onto for decades with no problems, anyldrite is relatively new , well it is around my parts,ive only seen one in nigh on 30 years [emoji33]

 

[Ajax123]

Hi Guys thanks again.

Can the Keracoll be mixed on site and applied like a traditional screed? Would we use it inside and out?

We've been rcommended a screeder(?) who does sand cement screed and were told he's really reasonable and good. So ideally we'd like to use him but it means no liquid/anhydride etc screeds I guess. We were also told it would be a lot cheaper and as always £matters. 🙁. Is there any reason to avoid traditional screed? Can drying time of normal screed also be reduced with additives?

Outside, can you tile straight onto the outside concrete slab or do u need some form of screed over it? We need to have a fall from the back if the house to the back end of the terrace (4500mm). If we did go with a liquid screed would it not 'self level' and lose the fall?

Thanks again for all your help. 🙂

Anhydrite is not suitable for this project anyway. You might as well just use a traditional sand cement screed with SBR added to give flexibility and water resistance rather than faffing about with special fast drying screeds.

 

[Ajax123]

Yes you can tile straight onto outside concrete, as long as its nice and flat [emoji15]
Nothing up with traditional screeds ,they have been tiled onto for decades with no problems, anyldrite is relatively new , well it is around my parts,ive only seen one in nigh on 30 years [emoji33]

how long does it take for something to be no longer new. Anhydrite has been used in burrnley and the surrounding areas for thirty years plus.

 

[trustiling]

Kerakoll comes with a liquid which you put down on the slab wet as your laying the 50mm 3:1 mix in a proper mixer with soft sand ideally.
No faff at all, the beauty of this stuff is it's perfect for outdoor work in the winter months with great temperature resistance, quick drying and laid with traditional bead and shuttering to guarantee a perfect smooth surface and your correct water run offs ensuring you don't end up with silly build up of adhesive on top of a concrete slab which will undoubtedly be undulating and rough in places. Your slab can be laid and left to dry then once a break in the weather slap the screed down tile next day simples.

 

[widler]

how long does it take for something to be no longer new. Anhydrite has been used in burrnley and the surrounding areas for thirty years plus.

Well,I've been in burnley for 44 years Alan, only seen one , and that was in clitheroe [emoji106]
I've plastered/tiled more houses than I care to think about, been on sites all around Lancashire from the new court house in Preston ( in the 90s) to new houses in and around burnley, all done in s/c screed.
Alan it's new to me around here, and to be fair, every builder I've ever worked for or with, and it's a fair lot, but that's not to say it's not been used, which it probably has.
And Alan, mate,you really need to stop spitting the old dummy out when someone says stuff against Anhydrite, nowt up with sand and cement IMO [emoji41][emoji106][emoji33]

 

[Ajax123]

Well,I've been in burnley for 44 years Alan, only seen one , and that was in clitheroe [emoji106]
I've plastered/tiled more houses than I care to think about, been on sites all around Lancashire from the new court house in Preston ( in the 90s) to new houses in and around burnley, all done in s/c screed.
Alan it's new to me around here, and to be fair, every builder I've ever worked for or with, and it's a fair lot, but that's not to say it's not been used, which it probably has.
And Alan, mate,you really need to stop spitting the old dummy out when someone says stuff against Anhydrite, nowt up with sand and cement IMO [emoji41][emoji106][emoji33]

I don't think I've ever spat the dummy out mate... I'm surprised you've only seen one as Preston, clitheroe, burnley have been busy with anhydrite for years... I've also never said there is anything wrong with sand cement...there are lots of technical advantages to anhydrite in comparison though.

 

[Ziggy1979]

Hi again and thanks for all your help.

alan, why is anhydrite not suitable in this instance? Does that leave us with sand/cement as only option?

is the keracoll just a separate thing used before the sand/cement goes down? Can we use it inside too with 75-85mm over insulation and UFH? Also, I looked at keracoll but they do many different products and I wasn't sure which one we'd need.

thanks again!

 

[Ajax123]

Anhydrite is not suitable for use outside. It is incredibly difficult to stick anything to a damp anhydrite screed and it would become damp simply by it being outside. You could use it on the indoor bits but I think you'd be better off using the same material throughout as it will be done in one visit making it more cost effective.