I have a large area of flat roofed accommodation (dining room 22m2, kitchen 14m2 and utility room 9m2). The existing insulation over all the flat roof area appears to be 1" of fibreglass!
I've just installed Celotex between the rafters of 2 bedrooms after the ceiling had to be taken down due to a leak in the flat roof (yes, I have an AWFUL LOT of flat roof!). Seems a good and simple solution in a case where the ceiling has to come down anyway.
I really don't want to have to tear down the perfectly sound ceilings in these other rooms, but I'm conscious of the enormous heat loss that must be taking place with the pathetic original insulation. (The external covering is less than 2 years old, so I don't want to spend a lot of money having that redone for a warm deck solution!)
It seems however that I have only two options - one is to tear down the ceilings, insulate between and below the joists and have the ceiling reboarded and finished.
The second option - because these ceilings are very high compared to the rest of the house and I have 170mm to play with under the existing ceilings while still maintaining headroom the same as the rest of the ground floor - is to follow the "advice" from Celotex to fix 150mm "battens" at 600mm centres, insulate between with 150 mm and board and finish.
This second option seems to be as expensive (although less dirty) than tearing down the existing ceilings and insulating between and below the existing joists. Can anyone suggest an economic and practical solution?
I am a competent diy'er and cost my time at £0 as I am retired, but would need a professional to board and finish and have no help available to fix 6x2" 6m long "battens" under the existing dining room ceiling!
I couldn't get a coherent answer from Celotex to my question about vapour barrier in the kitchen - in fact no response to that part of my enquiry at all.
All suggestions really welcomed: unfortunately I don't appear to qualify for any grant-aid towards improved insulation.
many thanks in advance