KyleT

So, just so I understand, this stuff would fix my problem because it completely covers the internal side of the roof and is a much warmer surface than the wood is therefore preventing condensation if any humidity hits the foam?

So I need to completely close the gap in the passage way like I have done in the utility too, and then fit the mushroom vents. This will be adequate ventilation?

As per the picture above my thought would be to install some breather vents in the roof at least 2 vents between each joist (so maybe 6 to 8 vents) and hopefully that should solve the issue?

There is a void of about 75mm above the insulation. There just doesn’t seem to be much ventilation. I’ve come across these https://www.roofingsuperstore.co.uk/product/klober-flavent-upvc-roof-breather-vent-standard-flange-100mm.html?gclid=CjwKCAiA_9r_BRBZEiwAHZ_v1wM_HjOK-Kn-w5AB_ULoYdv7Ic4FHr77_Ndq_R2Z4Rd6BXjx0trN2BoCp4oQAvD_BwE hopefully they do the trick. I have fitted a vapour barrier. I’ve simply taped up all joints and edges of the insulation.

I’ve just come across these https://www.roofingsuperstore.co.uk/product/klober-flavent-upvc-roof-breather-vent-standard-flange-100mm.html?gclid=CjwKCAiA_9r_BRBZEiwAHZ_v1wM_HjOK-Kn-w5AB_ULoYdv7Ic4FHr77_Ndq_R2Z4Rd6BXjx0trN2BoCp4oQAvD_BwE hopefully they can be fitted to the existing epdm.

It’s a condensing tumble dryer so it just creates heat in the room

I have a condensation problem on the inside of my garage roof. I noticed it in November, lots of condensation forming on the roof but only at the back half of the garage which is slowly being converted into a utility room. This hasn’t been a problem before, my only thought was maybe the tumble dryer was causing the problem as it is also located in the same area. I decided to buy some foam insulation at 75mm thickness as the void between the wooden beams and the garage roof was roughly 150mm therefore I knew using 75mm would leave another 75mm air gap between the insulation and roof. I did the job using foil tape to seal all joints and even spray foam in small gaps but make everything as air tight as possible. Today I decided to check the roof, running along side the garage is a full length passage way that has the same flat roof as the garage and I didn’t insulate this part as I wanted to inspect the garage roof over the utility room for more condensation. To my horror it is probably worse now. Water drops are dropping onto the foil back foam insulation with more condensation forming on the roof. It’s also so cold in there at the moment that some of the water is turning to ice. I can only assume one of two things is the reason. 1.) I need to also insulate the passage way too or 2.) some how the tumble dryer is still managing to penetrate through the insulation and create condensation. I’m slightly at a loss here. I’m not a great DIYer but will do what I can to sort this issue if anyone has any ideas? pictures can be seen here - https://imgur.com/a/IakHvYU