Understanding the Various Kinds of Timber Trusses

30 June 2017
 Categories: Construction & Contractors, Blog

Nothing has so much effect on the outlook of your house as your roof. Even with the best materials and wall setups, a roof that has not been installed properly can undo all the work you have put in. This is why you must be keen when choosing a truss for your home's roof. The truss determines the design and outlay of the roof. Additionally, it also determines how long the roof will be in place before it necessitates a significant repair. Treated timber roof trusses deliver good results in terms of resisting termite attack and rot. However, you are the one to determine the aesthetic appeal that best suits your home. Here are the various type of timber trusses you can choose from:

Pratt Trusses

Pratt trusses are characterised by multiple vertical beams between the rafters and the tie beams. Essentially, rafters refer to the inclined beams extending from the sides (eaves) of the roof to its peak. The tie beams form the lowest section of the truss, extending horizontally from one side to the other. Two rafters and a tie beam form a triangular shaped truss. A Pratt truss, therefore, resembles a triangle with several vertical posts crossing the interior. Certainly, a Pratt has immense tensile strength provided by the vertical posts. It is ideal for roofs with long cross sections, requiring optimal support before a change in the direction of the roof.

Howe Trusses

Howe trusses are another alternative you can go for when choosing a truss for your roof. They are configured in the same manner as the Pratt trusses with a slight variation to the vertical posts connecting the tie beam to the rafters. The only difference is that the vertical beams are installed at an angle opposite to the inclination of the main rafters. The essence is to provide as much angular support to the rafters as possible; enabling them to stand up to strong winds and storms hitting the roof at an angle.

King Post Trusses

King post trusses have a strong vertical post connecting the tie beam to the ridge of the rafters. Angular struts are then used to connect the rafters and the king post for additional tensile strength. Generally, a king post truss offers reliable strength throughout the cross section of the truss. However, it is quite expensive compared to the other types of trusses due to the high number of pieces required in its construction.