Which type of screed for UFH?

[JimLoskot]

Appologies if this has been covered before, but couldn't find anything.
I want to know the pro's and cons of traditional screed vs liquid screed over my UFH.

The make up is DPM, 100mm concrete slab, 75mm kingspan type insulation (with 25mm round the outside walls), thin vapour barrier with pipes ontop and then a screed.

Not sure weather to go for a sand/cement/fibres screed or same with some additives or a liquid screed.
Main interests are curing speed, screed depth, finish, cost and durability

Thanks for any info

Jim

 

[mointainwalker]

1)Liquid screed is normally only 50 mm vs 70 mm for trad screed.
2) Liquid screed is denser so transfers heat more efficiently
3) Related to 2) as the liquid surrounds the pipe much more closely so gives better heat-transfer.
4) Trad screed needs expansion-joints for surfaces greater than 30 m2, liquid is 300 ( I think )
5) It's so much easier to have the liquid pumped in
6) Liquid is going to be much more level with a smoother surface.

Not sure I understand your durability question. Neither is supposed to be left uncovered.

I laid one floor with sand/cement and additive and had two pumped. It;s not much use to you on a comparative basis as I live in France but the pumped floors were actually cheaper. I paid E 30/m2 ( about GBP 25)

 

[JoeMar]

if cost is a deciding factor then go with traditional screed with fibre.

 

[JimLoskot]

Thanks for the replies, I'm just going to get a few quotes now for the liquid screed. What sort of cost should I be expecting for 2 m cubed of the stuff (30m2 x 0.065m depth), pumped and finished?

 

[JimLoskot]

well its looking at about double the cost for the liquid screed, about £600 for sand/cement with fibres and £1200 for the liquid screed