Digging out kitchen floor/ screeding

[chris_o]

Currently in the process of a full refurb.

The very old kitchen extension had a solid floor with no membrane/insulation and the screed was cracked and blown in a few places where it had been hacked around for pipework previously.

I have broken up and dug down through the screed followed by red pavers, and finally soil, to approx. 200mm

I plan to spread and wack a small amount of type 1 to properly level it, followed by blinding of building sand, membrane, 100mm celotex and finally a 50/60mm screed. There will also be some pipework laid on the insulation before screeding.

Does all of the above sound ok?

Thanks in adance

 

[vinn]

Assuming that you are working in a fully cleared kitchen footprint?
That you have sorted what material will cover your finished floor so that you know where the FFL will be - presumably level with the next room FFL?
Any issues with dampness in the walls should now be taken care of.
Are all first fix issues sorted?

What you propose will work but I would do it this way:
I'd dig deeper and use a final concrete pour of min. 100mm - no "screed" needed.
Make sure that edge insulation is used.
Talk to BCO about buried pipework - some can be touchy abut it.

 

[chris_o]

Hi Vinn - thanks for the reply, I didn't receive an email notification but have since turned it on.

We have ended up screeding the floor to about 60mm, leaving it low enough to run an electric heating mat followed by self leveling compound. Everything went well!

 

[Doggit]

Sounds as though everything went well Chris, I take it you're putting down insulation before the heating mat goes down. There are a lot of threads here about electric underfloor heating disasters, and it could be worth checking them out.

 

[chris_o]

We have 100mm celotex followed by the 60mm screed. I naively assumed the electric heating mat would just go directly on the screed followed by slc? It won't be the main heat source for the kitchen, it's just to take the chill off the tiles.

 

[Doggit]

If you use a flexible adhesive to put down insulation boards first, then all the heat will go upwards, and the tiles will warm up quicker. You want to make sure your thermostat probe is in a channel in case it fails, and you can turn the heating matt upside down and then tile straight on to it without using the SLC.