Flat Roof Rafter Detail

The pitch of the roof determines the roofing material you can use.

Flat roof rafter detail.

In our rafter type sketch above the hip rafters are drawn in blue. Notice that the hip rafter forms what amounts to a descending ridge a single line that starts at the top of the roof and descends to the wall top plate at a wall corner. Main features flat roof design detail first off the flat roof design detail is an extremely basic direct and utilitarian design every single current trademark. They are nailed securely to exterior wall plates and to each other.

It must meet the local codes for thickness at least 3 8 which is also based on the rafter or truss spacing. A rafter that runs diagonally between the roof ridge and the top of the wall plate forming a hipped roof. Plywood or osb is the most common materials used for the roof sheathing. The size of rafters for a flat roof depends on the horizontal span of the building the type and grade of timber used and the load on the roof.

Having a manual for warm flat roof construction with details and a summary of rules to follow helps. Asphalt shingle can be installed on a pitch of 2 over 12 or greater. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. The rafters in a flat roof serve as ceiling joists for the space below.

A roof dormer may be gabled as in our sketch above or it may be a low slope or flat roof.