Originally Posted by championc
Would you recommend that I remove all the old Fibreglass and cut and run the panels between the joists ? If I was to lay the Panels over the top of everything, I would have a small air gap but could I still have possible condensation ?C
About to do just this in my detached bungalow with W trusses, in order to lay flooring down the centre section.
I've removed the cross layed fibre glass from the centre section and it's going out under the outer sides of the trusses, which will increase that fibre glass to 12" and is above the bedrooms, living room, kitchen, utility & bathroom. So I am then left with fairly new fibre glass in between 4" joists in the centre section.
The plan is to lay 1" thick battens across the centre section joists in three parallel runs that run the full length of the centre section and two 2" thick vertcial edge runs on each side parallel to the 1" battens. Effectively building a barebones frame to box in Kingspan K7 Kooltherm 50mm boards. I'll have to cut the Kingspan down the middle to get them up the loft hatch, but I'll lay the two cut pieces back together once up and they should be fairly tight together.
Once the kingspan is in it's box, I'm planning to just lay 8'x2' chipboard flooring on top, and if it's moving then 2 widgets per exposed 8' chipboard edge to keep the boards in place.
There'll be a 6" gap at each side of the K7/floor box, which I'll just refill with fibre glass to prevent upward heat there. The centre section will then have 4" fibre glass between joists and 2" Kingspan Kooltherm K7 (equivalent to 6" fibre glass) on top, or 10" fibre glass equivalent. This is all above a hallway and part of the living room.
I'm hoping that the 1" thick battens under the Kingspan will suffice as an air gap to prevent condensation on the joists and allow whatever electrical cables to run across the centre section (after I get an electrician to tidy that up first!).
Anyway, I think this is a relatively good plan to allow me to floor my attic for storage of little used items, while maintaining the insulation and avoiding condensation and deterioration of electrical cables.
Any comments or ideas?