If you are planning a Loft Conversion which includes the construction of a Rear Box Dormer then you will need to choose a material covering for the Flat Roof of that Dormer. There are lots of different products to choose from and different builders have their own preferences but generally they are one of three types of product. Here we try to give you a broad idea of what these are: Felt Flat Roofs for Dormers of Loft Conversions A Felt Flat Roof on the Dormer of your Loft