The roof of your house does more than just cover your house and keep the weather out. It helps to keep your house straight and plumb. Your roof is going to need to have support so that it can do its job. That's because any kind of roof would just collapse in on itself and your house if you didn't have any support under your roof. There are various ways to support a roof and various kinds of supports. Two of those supports are rafters and trusses. What are they and what are the differences?
Rafters are a basic triangular-shaped support system for your roof. Each rafter has two sloping sides that meet up at the peak of your roof. Under that connection, there is a piece of wood that is attached to both sides, called a collar, which gives the rafters additional support. The rafters then run down to the ceiling joists and are attached, which forms the bottom of the triangle. When the total rafter is put together, it gives the roof the support that it needs as well as making sure that the load of your roof is spread throughout the entire house, so that no one area of your house is going to hold more weight than any other, which would cause a weak spot in the roof. Rafters can be pre-made inside a workshop and then transported out to the building site, or they can be built onsite. Rafters tend to be less expensive to use than trusses are because they involve less work and fewer materials.
A truss is also a triangular structure. Instead of being just one basic triangle, each larger triangle is made up of other smaller triangles. The way that those triangles are set up within the truss depends on which style of truss is being used. The support structures within the truss are precisely engineered so that they carry the weight and load in specific ways. Because of that, they are constructed offsite and then transported to the site so that they can be installed on the roof. Trusses are more expensive than rafters are because they involve a lot more work to put them together, including calculating the load of the roof and the stresses that it will have to deal with.
Supporting a roof is important. Trusses and rafters are 2 ways to do that. For more information, contact a company like Campbell Truss Company Inc.