Principal rafter

Principal rafter

One of several such wooden rafters that extend from the ridge uninterrupted down to the wall plate; more massive than common rafters, and framed into a tie beam that makes the whole assembly more stable.

principal rafter

In a timber-framed house, one of several such rafters that extend from the ridge of the roof down to the wall plate; somewhat heavier than a common rafter; often located at a corner post, story post, or chimney post and framed into a tie beam. Principal rafters, together with the principal purlins, form a roof framing system having considerable stability. Also called a blade.
References in periodicals archive ?
This had meant the doorway between the rooms was a peculiar shape to allow for the struts and principal rafters of the trusses.

Full browser ?