Hello, I am looking for a fire proof timber paint for application to a workshop wall (2) that is along a bordering wall, in order to comply with building regs my understanding is the exterior needs to be fire resistant for 30 to 60 minutes. Which products would be needed to achieve this and approx how much product for coverage. 2 walls are wooden clad. W 6m x H 2.2m & H 2.2m x W 5m. Our tradesmen will be placing the order for us, is their a trade price? Thank you, M