The simplest type of roofs, usually used in the construction of small and relatively inexpensive the outdoor stages, in the construction of this type of roof trusses are used Trisystem 250, Trisystem 300 and QUADRO 290. Applied systems provide good strength properties at the behavior of the small dimensions of same truss, it is of particular importance in the case of transport, because does not require large cargo spaces. This type of roofs work best when scene's dimensions are: 6m x 4m, 6m x 6m, 8m x 6m.