Even if you’re having a contractor put up the roof on your new house or addition, it’s worth your while to think about the type of roof framing you want. Here are a couple options you’ll want to consider.
Conventional framing uses rafters which sit on the top plate of the wall, and meet in the middle at a ridge board — in a simple gable roof.
Back in the old days, the rafters may have been 2x4s 24″ on-center. These days, they’re more likely to be 2×8 or larger, which adds strength and allows more room for insulation if you’re planning a cathedral ceiling (you’ll still need more space, though). In many situations this will do the job nicely, and the material costs are fairly low. On the downside, laying out and cutting rafters is something of a disappearing art, and can add to your labor costs.
Engineered wood trusses are pre-fabricated sections — basically a triangular framework strengthened by “web members” and connector plates, so you’re getting a stronger structure considering the amount of material it uses. The assembled trusses are more expensive than standard framing materials, but can save you on labor since they’re easier to install.
The strength of trusses allows you to consider a few more design options. Cathedral ceiling and large open concept rooms can be easier to design and build with the strength and span of trusses.
Talk to your designer and contractor about the best method for your particular situation and compare the costs of the installed system.