BlueTangClan

In theory I think we could add insulation externally and cover again, but I'm guessing any roofer would prefer to just to re-roof with a warm roof and we weren't really looking at external options at the moment (maybe we will be now) and due to neighbouring roof levels I doubt it would be much more than 70mm PIR. Now this is where I start doubting every decision I come to. It has woefully inadequate insulation by todays standards. BUT has this lack of insulation combined with no vapour barrier been a benefit to the roof? ie reducing the difference in internal and external temperature and/or allowing it to breathe back into the house? Would installing a vapour between the plasterboard and rafters be a mistake?

Thanks for the information. I think it looks like we'll end up reinstating the plasterboard with a vapour barrier and not adding anything else. And hope it looks after itself like it seems to have done for the past 50 years. Next time we re-roof I'll look into the possibilities of making it a warm roof.

We recently had our plasterboard ceilings taken down in our mid-terrace 1970's house. I thought I would be able to add some insulation before replacing the ceilings, and after getting some advice from a family member who had a contact with a "Technical person" at an architects, was all set to place insulation between joists leaving at least 50mm gaps to the roof. However, the more I looked into things (videos of sweating rooves) the more worried I became about doing this. The roof has no ventilation and previously had no vapour barrier, has also had leaks previously, but with no long term issues arising from these. Hopefully the attachments will help explain things (please excuse my diagrams). My questions are; Can I safely add insulation to this roof from inside? if not, do i just put a vapour barrier or a VCL up and then plasterboard? Do I need to get a Residential Surveyor in to tell me what to do? Any help and advice with any of this is greatly appreciated and will hopefully help to ease my anxieties about this. Thanks, Jonathan

I stumbled across this place while searching for some answers for my 1970s flat roof conundrums which keep cropping up like whack-a-moles. Hopefully I shall find some answers and my anxiety levels will start decreasing.