Jetfloor detail

[RandAbuild]

Jetfloor is now mostly in - the final insulation will go in later.

The tricky part was the positioning of the large (420kg - we have a span of 5.5m) ground beams. We hired a 17m telehandler for the day, but lining it up so it was central to the building was a problem. It also tended to nip the dpc in places, resulting in lots of to-ing and fro-ing. The insulation thickness will vary between 80mm above the beams to 230mm between them. With a P/A (perimeter to area) ratio of 0.46, this results in an overall U value of 0.15.

[ProDave]

That's interesting. So nothing under the floor, no membrane, just bare earth?

[RandAbuild]

No, the membrane goes above the beams & insulated blocks, then 80mm EPS sheet, then 70 reinforced screed + UFH.

A normal beam & block floor has nothing underneath the beams, just min 150 air gap.

[Vijay]

Is 150mm underneath standard? Just looked at my plans and it states a 225mm minimum void

I'm sure I read somewhere about putting a layer of hardcore down to help drainage and also weed membrane????

Edited July 17, 2016 by Vijay

[RandAbuild]

Vijay - I'm sure you can do this but I don't think it's necessary. Building Control was OK with leaving it as bare earth.

150mm is the minimum - I think ours is at least 200 and 300 in places.

[Barney12]

18 hours ago, Vijay said:

Is 150mm underneath standard? Just looked at my plans and it states a 225mm minimum void

I'm sure I read somewhere about putting a layer of hardcore down to help drainage and also weed membrane????

When we did the renovation and extension on our last place we left bare earth. Nothing is ever likely to grow.