Help, I'm confused - still struggling with an issue and getting conflicting advice:
I want to put thermal bubble wrap at the rafter level of the loft. At present it is a cold loft (with joist level insulation) but after severe flood damage, I want to make it a warmer loft to prevent pipe freeze.
I have boards covering the joist insulation over most of the loft and have been thinking to bring the bubble insulation on the rafters right down to pin it to the loft boards (adding new boards where necessary).
The intention is during colder spells to leave the loft door open and kind of heat the space- making it a warm loft.
However I have been told by friends that I must leave a gap for ventilation to avoid condensation between the bubble wrap and the joist insulation. If I do leave a gap I'll have trouble keeping it warm. (the usual 50mm gap between sarking and bubble wrap would be there of course)
If I don't insulate with bubble wrap and leave the loft door open, won't I get condensation anyway?