Floor build up for ground floor UFH

[HughF]

55 minutes ago, Dave Jones said:

 

only issue will be it wont be flat enough to put a floor on no matter how much you float it. Screed is.

Nothing a bit of self leveller won't fix... To be honest, this is flatter than the kitchen slab and that's got vinyl on it just fine.

[Chanmenie]

I had 100mm fibre reinforced self compacting concrete and that’s perfectly flat and level. It’s poured like a screed so self levels 

[HughF]

The stuff we put down went down like water….

[LiamJones]

On 29/08/2023 at 20:04, Chanmenie said:

I had 100mm fibre reinforced self compacting concrete and that’s perfectly flat and level. It’s poured like a screed so self levels 

Interesting, have you got a link to the product/company you used? 

[LiamJones]

My concern now with just the concrete is how easy it’ll be to get level enough. Screed obviously solves that problem.

[LiamJones]

On 29/08/2023 at 20:06, HughF said:

The stuff we put down went down like water….

What did you use? 

[HughF]

10 hours ago, LiamJones said:

What did you use? 

Concrete, straight off the readymix truck. I think it was 10mm down rather than the 20mm down we used for footings 

[HughF]

Best photo I have, but you can see it went down nice and flat.

[Chanmenie]

Yeah mine was fine aggregate, max 10mm 

they sprayed a curing agent over the top to stop it drying out too quick 

Edited September 3, 2023 by Chanmenie

[LiamJones]

55 minutes ago, Chanmenie said:

Yeah mine was fine aggregate, max 10mm 

they sprayed a curing agent over the top to stop it drying out too quick 

thanks, how are you doing/have you done your internal walls? 

[Chanmenie]

I’ve started them but they are not load bearing 

 

[Paul Marlow]

If you're after more info on the thickness and grad of concrete to use i found the below article pretty useful:

https://www.singhconcrete.com/understanding-the-importance-of-grades-and-strengths-in-ready-mix-concrete/

[vala]

An update to this thread.

Bit of a u-turn but we've ended up booking in a firm to provide a polished concrete floor finish. They're also going to pour the concrete.

Architect noted my area had a 2-3% chance of radon so suggested to keep BC happy install a radon barrier after sand bind.

so build up now is:

150mm type 1

50mm sand

radon

175mm PIR

dpm

ufh pipes stapled to PIR

125mm concrete

 

Concrete firm install a193 mesh and use fibres as part of their work.

 

SE is satisfied the compressive strength of the PIR will support the concrete.

 

Is FI5000 PIR worth using over GA4000?