Timber Framers Guild Forums General General Forum Questions General - older posts Scissor Truss?

Hello to the group. I was wondering if anyone could give me some quick input. I am planning the construction of a garage/studio/workshop on our property. The building is going to be somewhere around 24x30 or perhaps 24x36. On the gable end of the building I would like to build a large sliding door which would allow me to drive vehicles in for repair, one of which would be a backhoe. I was thinking that a scissor truss would be a way to get as high as possible right in the center (under the ridge) for the hoe withough having to have very tall outside walls (8 feet was planned) and still maintaining a moderate pitch (perhaps 5/12 or so). Additionally the trusses would be fairly easy consisiting of only 4 timbers each. Any input? I am planning the building to use eastern white pine as I am unsure what will be available at the mill in WV when we move there but if something better is available I would upgrade to perhaps make the timbers a bit smaller.

Thanks,.. Mark

Mark, A scissor truss with a 5/12 principal rafter will not give you much extra headroom. Your lower members would be somewhere in the 2-3/12 pitch range and that is not very much rise in the short run to the outer edge of your door. A better approch might be to heavy frame your door opening and extend the posts to your rafters.