Wet screed - Tile Advice

[Andy Allen]

Looked at a job, client wants to fast track tiling a new floor with a heat mat.
This is what they have come up with..
75mm sand and cement screed
After 3 weeks apply tilemaster prime and grip......wait 7 days, install heat mat and cover with tilemaster floor flex slc, when dry, tile with porcelain plank tiles using tilemaster flexible adhesive. Sounds iffy to me......any of you tilemaster boffins help me out here.

 

[J Sid]

what type of heat mat?
what size floor?

 

[Old Mod]

That screeds never gonna be dry in 4 weeks Andy,
and to my knowledge you can't use floor flex on a green screed either.
You'd have to use something like Arditex NA
ARDITEX NA - http://www.ardex.co.uk/ProductDetail.aspx?ProductID=18

Fast tracking a wet screed usually needs a water vapour barrier.
There has to be an escape route for the moisture.
You could possibly use TM ultimate with variopro UFH or Ditra heat taped and jointed.
If floor is flat enough, don't even need to slc.
And you only need to wait 7-10 days after it's laid, not 4 weeks.
As soon as it's hard enough to be mechanically repaired, I think the term is.

Ok..... well I've just checked write ups on both variopro and Ditra heat and neither mention a vapour barrier like Ditra 25 and Dural, it's worth a phone call to check it out Andy.

Two floors Gary and I did last week.

 

[J Sid]

my thoughts also

 

[Andy Allen]

what type of heat mat?
what size floor?

Don't what mat....I'll find out.
It's a 21m2 floor.

 

[Dumbo]

Looked at a job, client wants to fast track tiling a new floor with a heat mat.
This is what they have come up with..
75mm sand and cement screed
After 3 weeks apply tilemaster prime and grip......wait 7 days, install heat mat and cover with tilemaster floor flex slc, when dry, tile with porcelain plank tiles using tilemaster flexible adhesive. Sounds iffy to me......any of you tilemaster boffins help me out here.

I don't know Tile master products but priming it seven days before work commences will surely slow down moisture escape .

 

[Andy Allen]

That screeds never gonna be dry in 4 weeks Andy,
and to my knowledge you can't use floor flex on a green screed either.
You'd have to use something like Arditex NA
ARDITEX NA - http://www.ardex.co.uk/ProductDetail.aspx?ProductID=18

Fast tracking a wet screed usually needs a water vapour barrier.
There has to be an escape route for the moisture.
You could possibly use TM ultimate with variopro UFH or Ditra heat taped and jointed.
If floor is flat enough, don't even need to slc.
And you only need to wait 7-10 days after it's laid, not 4 weeks.
As soon as it's hard enough to be mechanically repaired, I think the term is.

Ok..... well I've just checked write ups on both variopro and Ditra heat and neither mention a vapour barrier like Ditra 25 and Dural, it's worth a phone call to check it out Andy.

Two floors Gary and I did last week.
View attachment 86822 View attachment 86823

They seem to to pinning there hopes on this tilemaster prime and grip.....the supplier has told them if you paint this on the floor screed after 3 weeks...wait 7 days ...you can crack on.....mind you the same supplier told them 4 bags of slc would cover a 21m2 ..200 watt heat mat..

 

[Spare Tool]

Just throw this one in the mix...fix Dural or ditra onto screed using tm ultimate, leaving an inch clear round perimeter, tape joints, skim of rapid level 30 over Ci/ditra and fix heat mat same day, slc again over heat mat...good to go

 

[Old Mod]

They seem to to pinning there hopes on this tilemaster prime and grip.....the supplier has told them if you paint this on the floor screed after 3 weeks...wait 7 days ...you can crack on.....mind you the same supplier told them 4 bags of slc would cover a 21m2 ..200 watt heat mat..

To my knowledge prime and grip is for priming impervious substrates Andy.
That's why it contains particles, to add a key.
If it's only 21m why are they not installing wet UFH.
Can't a floor that small just be hooked up to the normal heating system? Probably talking rubbish, but thought I'd heard it somewhere.
Please correct me if I'm wrong
@Chalker?
Then you can Ditra after the 7-10 days, tape joints using keba and kerdi Coll and your green screed is good to go.

 

[Flintstone]

None of that they have suggested sounds right to me, what's prime plus got to do with anything? That's dry in an hour so what's the weeks wait for ? It's only a gritty primer for one porus surfaces I would agree that you need some form of barrier mat down.

 

[Old Mod]

Just throw this one in the mix...fix Dural or ditra onto screed using tm ultimate, leaving an inch clear round perimeter, tape joints, skim of rapid level 30 over Ci/ditra and fix heat mat same day, slc again over heat mat...good to go

Build up over Ditra can't exceed 10mm including adhesive. They don't advocate using slc over it, but it's doable.

 

[Spare Tool]

Build up over Ditra can't exceed 10mm including adhesive. They don't advocate using slc over it, but it's doable.

How about insulation boards fixed with ultimate, taped and left clear of perimeter instead of crackmat?

 

[Flintstone]

They are gonna well and truely trap moisture in aren't they

 

[Spare Tool]

They are gonna well and truely trap moisture in aren't they

It'll escape round perimeter..

 

[Dumbo]

None of that they have suggested sounds right to me, what's prime plus got to do with anything? That's dry in an hour so what's the weeks wait for ? It's only a gritty primer for one porus surfaces I would agree that you need some form of barrier mat down.

I reckon your fish is bigger .