Whether it is or is not reasonable is probaby not a profitabe discussion to have with Building Control.Hi,
I've recently had a flat roof (warm) installed by a local contractor, who used 100mm Kingspan over the main deck, followed by torch-on felt. BC now advise that the insulation is too thin: 100mm gives 0.22W/m2K, requires 0.18W/m2K. Is that reasonable?
Who was the person who designed the roof and decided that it would comply?What is my recourse?
Who applied for Building Regulations approval?
You should be asking these questions here:can anything besides stripping the roof back to the deck and adding insulation be done? A quick googling reveals that 130mm should be OK: can 30mm be added under the main deck (between the rafters), or does this then stop being a warm roof?
not here: