Monday, 15 July 2013

Types of Roof

Types of Roof

Timber Roof Trusses

Trusses are the design that a timber roof can take. There are many different types dating all the way back to medieval times and picking a truss is the most essential part of building and installing a timber roof.

Different types of Trusses

There are two main types of trusses; closed trusses and open trusses. A closed truss has a tie beam and a ceiling so the framing is not visible. An open truss is a truss with an interrupted tie beam or scissor truss which means that there is a vaulted ceiling area. An open truss will also have a roof framing that is visible 
Below is a list of Closed Trusses:
Kingpost Truss: Has two main rafters which are the tie beam and the king post. This is the most simple truss and is used in conjunction with two angled struts
Queen Post Truss: Has two principal rafter and two vertical rafters
Palladian Truss:  Similar to the Kingpost cross with the angled struts being lowered to the base of the framing
Liegender Stuhl: A German truss where the top chords are angled on leaning and chair in the sense of a support
Below is a list of Open Trusses:
Arch-braced Truss:  The principal rafters are linked by a collar beam which is supported by two arch braces which help make the structure more rigid and stable and helps transfer the weight of the roof to the supporting wall
Scissor Truss: The two distinguishable features that form the scissor truss are 1) the joint where the bottom chords pass must be firmly connected and 2) the rafter feet must land on the bottom cords.
Picking your truss is a vital part of building your timber roof and extensive research should be done to make sure you get the timber roof meant for you.