Concrete floor recommendations

[John Benton]

Hi

I've got a concrete floor to tile in January and at the moment it is dry and has no damp. Although the plane is even, the floor is not level. I want to put down an SLC to level the floor, and tile, prior to kitchen being fitted. I have the following questions to make sure the customer doesn't have any future problems:-

1) Should I as a precaution put down a damp proof membrane prior the SLC going down?

2) What dpm would you recommend, liquid?

3) Should I prime, prior to putting down dpm, if a dpm is required? (I will of course prime if no dpm goes down)

Cheers

John

 

[Ian]

Do you know if there is a DPM under the substrate? How old is the property?

 

[White Room]

As above ???

 

[Ajax123]

how do you know if it is dry?

 

[John Benton]

The property is quite old but the floor is in a newer extension added, I would say probably about 30 yrs ago. Don't know if theres a dpm under current substate

 

[Ian]

This is the liquid DPM I use F Ball F76 Waterproof Liquid Surface Membrane 10KG | eBay

And this is the primer I use with it Fball P131 Primer screed primer

 

[White Room]

I would have thought 30 years ago damp membranes were being fitted...

 

[Ian]

Just to add, if you do use this product you will need to use a compatible SLC over it. F.Ball Stopgap 300 is one of them, there are a few suitable.

 

[John Benton]

When I say its dry, this is what the builder has told me, who has done a lot of work in the house prior to me doing any of the floor. Whether he has measured moisture content is a different matter and I will contact him ASAP to find out

 

[John Benton]

This is the liquid DPM I use F Ball F76 Waterproof Liquid Surface Membrane 10KG | eBay

And this is the primer I use with it Fball P131 Primer screed primer

Is this product applied by roller and would that size cover 20m2, I'm guessing it will

 

[Ajax123]

liquid dpms generally laid with a roller but to be done right you should use a notched trowel. there are loads of DPMs they are all much of a muchness. I prefer one coat systems generally cos Im a bit lazy and dont want to do two coats. they are not generally designed to cope with rising damp though so ditra might be a better option if no DPM under the slab.

 

[Ian]

Is this product applied by roller and would that size cover 20m2, I'm guessing it will

That size covers 30 m2, it's trowelled with a 2mm trowel (supplied with the kit) and then you roller over it. This process gives even coverage with no weak spots.

 

[John Benton]

liquid dpms generally laid with a roller but to be done right you should use a notched trowel. there are loads of DPMs they are all much of a muchness. I prefer one coat systems generally cos Im a bit lazy and dont want to do two coats. they are not generally designed to cope with rising damp though so ditra might be a better option if no DPM under the slab.

So that would be a case of priming, Ditra, SLC and then tiling

 

[Ajax123]

So that would be a case of priming, Ditra, SLC and then tiling

yes, stick the ditra down though.

 

[John Benton]

And the tiles.....haha

 

[John Benton]

Since found out that a large part of this floor was concreted with a dpm installed a couple of years ago. Would I still be better going down the Ditra, slc and tile route, do you think as a precautionary measure?

 

[Peter]

The SLC should be under the Ditra.