Currently doing a garage conversion on a house that I recently bought. Using Celotex with a thickness of 75mm for the floor and walls won't be a problem. However have had the building regs round today and they are stating that for the roof we need to have a 50mm ventilation gap and then 125mm thick ventilation board, this is a problem!
The joists are 100mm and thats all I want to play with for both ventilation and insulation, the reason being is because there will be little head room left if we have to come down 175mm (already rasing the floor by 150mm to make it level with others).
So my question, is there anything out there with an equivalent U value to a 125mm Celotex board but available in 50mm?
Thanks
The joists are 100mm and thats all I want to play with for both ventilation and insulation, the reason being is because there will be little head room left if we have to come down 175mm (already rasing the floor by 150mm to make it level with others).
So my question, is there anything out there with an equivalent U value to a 125mm Celotex board but available in 50mm?
Thanks