jc212

Thanks for the replies. I just pulled a few other downlights and seems the draft is especially bad on one row of lights between a pair of joists. Putting my phone up with camera on I can't seem to find any obvious leak points. Honestly no idea what to do! Ive ordered an IR thermometer today and am thinking of doing some tests to try and verify how bad the current situation actually is. Will take a few data points on an cold day (this weekend): Room temp Ceiling centre temp Ceiling near downlight Ceiling near lantern Void temp Outside temp Worthwhile do you think?

Thanks for that Mr Punter, I will take some measurements over the weekend. Plasterer just been round to quote. £450 labour for 2 days. I've priced 50mm PIR backed plasterboard + extra long drywall screws ~ £360. It's a fair bit but we spend a lot of time in here. Also proposing to move away from downlights and go for 2 surface mounted lights instead, which i guess will help keep a warmer envelope.

Hi, we moved into our house earlier this year which has a single storey flat roof extension on it. The hope was it would be lovely and warm, unfortunately we're finding it's not. I took a downlight out yesterday to have a look into the ceiling void. From what I can see this appears to be a warm roof. The ceiling is polystyrene backed plasterboard, there's then a void of around 200mm with a wooden deck. I am guessing (hoping) there is insulation laid above this underneath the roof itself. The tiny amount of polystyrene insulation on the back of the plasterboard would not meet modern insulation standards and building control would not have signed it off (I am guessing). This void appears to be pretty drafty and cool, so guessing there's some leaks somewhere. It's very difficult to find out exactly though as there's no access of course. One thing I am considering is overboarding the existing ceiling and lantern vertical sections with 50mm backed PIR insulation and then making it as airtight as possible to minimise moist air reaching the cavity. We have plenty of ceiling height to do this. Any thoughts on this approach?