Thanks for your replies...
The building control's problem is not with the U value but with moisture ingress. I spoke to the technical department at celotex who basically said in reality the wall would be fine, but they couldn't issue a certificate for 'one offs' their certificates have to...
Hi,
My builder has built a brick brick cavity wall and filled the cavity with celotex CG4000 and it meets the required U value, but hasn't left the 25mm airgap between the insulation and the external course. There is 10 - 15mm. Building control say I must rebuild with the 25mm gap. My builder...