SLC over Hardie or vice versa?

[Grime]

Hi All - on a new job today and I'm gonna need to raise the floor level further than the 12mm Hardie I'm installing will provide. So I'm gonna SLC it. The question is does it make any difference whether I install the Hardie then SLC over it, or lay the SLC then install the Hardie? I've never had to use both on the same job before.

Many thanks.

G

 

[Flintstone]

What's the floor? Wood? Concrete ?

 

[Grime]

Concrete. Should've said.

 

[Flintstone]

Best option, Don't bother with hardie, just use slc to get to the required height

 

[Grime]

Lol. I said as much to the customer and he wasn't happy. But is there any reason why I should Hardie first or SLC first?

 

[Flintstone]

Probably hardy first so your not guessing height

 

[Spare Tool]

Far as I'm aware Hardibacker is not designed for concrete floors, just to glue and screw on wood...slc all the way

 

[Flintstone]

Your right Andy I just read That.
No more ply you can

 

[Qwerty]

Or Marmox/ wedi/ jackoboard

 

[Mark Frost]

Your right Andy I just read That.
No more ply you can

Yes NMP I have done this. Worked brilliantly bringing a floor to level from 20mm out. It was quicker for me to glue 12mm NMP than to self level.

 

[LM]

Slc is the cheapest way to build up an uneven floor.

 

[Spacey]

Stopgap 800 deap base No aggregate required goes up to 50mm in one hit stronger than concrete and dries very quickly

 

[Mark Frost]

Slc is the cheapest way to build up an uneven floor.

Yup.. but it's a good substitute if your struggling to get enough

 

[Dumbo]

Yes NMP I have done this. Worked brilliantly bringing a floor to level from 20mm out. It was quicker for me to glue 12mm NMP than to self level.

Don't know how sticking all those separate boards then drilling and screwing can be quicker than levelling .

 

[Grime]

Cheers for all the advice, much appreciated. I knew that SLCing the floor would be faster and probably cheaper but the Hardie must be used as it's been bought and cut.

Cheers.

 

[Grime]

I forgot to say that I called the Hardie technical line about using it on concrete floor and was told that it's not a problem but the boards must be mechanically drilled, ie using wall plugs.

Thanks.

 

[Flintstone]

Weird about having to screw them to the floor