The structure may be concrete or metal. Nevertheless, precast concrete beams are normally used for spans of up to 10m, with metallic beams used for greater spans (up to 13.30m).

The roof is attached either directly to the structure (if it has the correct angle) or by using a special support edging that sits on the roof at the required angle.

There are two types of tension bar that can be used in this type of roof, each with different objectives.

• Horizontal tension bars are used to reduce the horizontal forces provoked by the roof on the beams upon which it is supported. This allows us to reduce the edge of the support beam
• Guy tension bars are used to counterbalance the suction action of the wind and stretch from the beam supporting the roof to the roof’s central point.

Tension bars are necessary for spans of more than 10m and, above all, in those buildings with metallic support structures.