Roof design is quite a complex field and involves many calculations regarding the strength of the materials used. A roof has to withstand very high wind speeds and snow loading and each roof is designed to carry the covering, usually tiles, that is put on it.
The coverings are fixed onto battens which are spaced out up the roof. Each batten is nailed to every rafter it passes over. Underneath the battens is a roofing felt or membrane. There are various makes of membrane but each one serves as both a vapour and a dust barrier. That is, it stops warm air from inside the roof space hitting the cold underside of the tiles which causes condensation. This roofing membrane is not a secondary waterproof layer for the roof.
All of our roofs and floor platforms are manufactured loccally using MiTek software. See below for some examples of roofs and floor platforms we have designed.