Been advised we used an incorrect product on our summerhouse. We purchased the more expensive roofing felt, however if this is what was delivered was more than useless. The shed is sodden on the roof. Plus the walls are leaking. On querying we were told that as we had not coated with the correct preservation there was nothing they could do. Even if this were the case this should not prevent the roofing felt from doing its job and stopping the water coming through the roof. On top of that the doors have never closed properly and am very disappointed in the product and lack of positive customer service.