A
Alienjoker
Hi everyone,
We’re having a ground floor extension and the new area is block and beam with 100mm celotex. The existing connected floor space from the main house has had the screed removed and the concrete sub base had varying screed (since removed) between 50mm and 105mm in various places. I realise I need to get some insulation underneath for the UFH system to go in, but with such wild variations, what insulation would you recommend? I have found foil from Actis or Superfoil @ 6mm which will work everywhere with minimal install effort, vs installing tile backer boards between 6 and 10mm but I guess that would need the subbase to be levelled to take the rigid boards so literally loads of self levelling compound and then tile adhesive. Once insulated, I was looking to get liquid screed poured around UFH pipes to then get the levels between the areas the same.
My main concern is what type of insulation to use as well as what happens when the screed (within the vapour barrier) crosses the threshold between old and new floor areas? Is there a big risk of developing cracks all around the edge of the divide between old and new as the block and beam floor is somewhat springy and there will always be a lip/threshold between them before the screed goes in.
Any advice would be greatly appreciated
Thanks
Andrew
We’re having a ground floor extension and the new area is block and beam with 100mm celotex. The existing connected floor space from the main house has had the screed removed and the concrete sub base had varying screed (since removed) between 50mm and 105mm in various places. I realise I need to get some insulation underneath for the UFH system to go in, but with such wild variations, what insulation would you recommend? I have found foil from Actis or Superfoil @ 6mm which will work everywhere with minimal install effort, vs installing tile backer boards between 6 and 10mm but I guess that would need the subbase to be levelled to take the rigid boards so literally loads of self levelling compound and then tile adhesive. Once insulated, I was looking to get liquid screed poured around UFH pipes to then get the levels between the areas the same.
My main concern is what type of insulation to use as well as what happens when the screed (within the vapour barrier) crosses the threshold between old and new floor areas? Is there a big risk of developing cracks all around the edge of the divide between old and new as the block and beam floor is somewhat springy and there will always be a lip/threshold between them before the screed goes in.
Any advice would be greatly appreciated
Thanks
Andrew
