Insulation

Fibreglass -vs- Celetoex/Kingspan in rafters in loft room.

Anonymous user 15/03/2024 - 2.40 PM

Is fibreglass insulation between rafters good enough? We have just moved into a property which has a usable loft room with en-suite. We suspect it wasn't passed off by the Council as a usable bedroom (we may be suing our solicitor on this, but that's another thread!). The room loft currently has fibreglass insulation in-between the rafters as opposed to Celotex/Kingspan. In this hot weather, it is like an oven up there and quite unpleasant. I am considering getting a builder to rip out the fibreglass, replace with Celotex/Kingspan and re-plaster the ceilings as I have been told by a couple of people that it'll likely be very cold up there in the winter. Ripping the ceiling down and replacing all the insulation will obviously be quite an expensive job and I wonder if it is worth it or whether I should just get some air conditioning installed and maybe an extra Velux window or two, which would certainly help in the summer with air flow and ventilation, though I am worried about heating bills in the winter if the fibreglass doesn't retain the heat. Is Celotex/Kingspan really that much better for insulation in-between roof rafters than fibreglass? Will I just be wasting my money by doing this job? Any comments welcome. Thanks in advance.