Timber trusses

Roof trusses in Europe appeared al list in the Roman era and are in use until now adays. Various styles of trusses are discussed in this work. The investigation here concentrated on the differences between ‘open truss’ to ‘close truss’. Backed with computerized simulation, it was found that ‘close truss’ has a significant advantage of about 30% over the ‘open truss’ truss. An offer for the evaluation of the truss was presented and as well as explanation for changing back from ‘close truss’ to ‘close truss’ started in the mid-18th century.