Surfer-Rosa

Thanks for your post, you're right, there is no way for air to circulate currently, above the pir. We are planning to make ventilation gaps through some of the firring and have two vents at (almost) opposite ends to encourage air flow in the cavity wall around the building. Thanks again for your comment. Do you have any thoughts on the original issue?

We have just had a flat roof light installed, and flat roof re-felted. The company we used made a lot of mistakes during the project that they had to correct. Since they left we've removed the plasterboard to install new lighting, and are concerned about the structural integrity of the rafters. The builders cut the rafters going left to right, and attached the upstand to doubled up original rafters with joist hangers.. One main concern is that the new rafters used to double up the original rafters aren't in contact with the brick of the supporting wall, meaning that while they do provide bracing for the original rafters, they do not help distribute the weight of the new structure. Is this safe? Any thoughts appreciated.