Rafters And Trusses - What's The Difference
One of the most important features of your new home is the roof. Without it, your home would be open to the elements. Your roof keeps you dry, warm, and comfortable in all seasons. The average person, however, knows very little about how their roof is assembled even though it has such a huge impact on their lives.
Rafters are long wooden boards that support the weight of your roof. One end rests on the top of the wall while the other end angles up towards the roof. At the top of your roof, the rafters connect to the ridge beam. The ridge beam, sometimes called a ridge board or even just the ridge, is a long, horizontal board that spans the length of the house or that particular section of the house, depending on the design. All the rafters attach to the ridge beam and together they make up the roof. In residential construction, ridge beams are typically wood but can be steel I-beams when the distance that needs to be spanned is great.
Rafters are convenient because they allow for a larger attic space. Rafters are only along the outside perimeter of the attic space with no horizontal cross members. This allows for an attic with plenty of headroom or the option of adding a cathedral ceiling to the room below.
While rafters are desirable, they are difficult to install for the uninitiated. A skilled carpenter is needed because rafters are individually cut on the job site as they are installed. This requires a tradesperson with the skill and experience to figure out the angle of each cut, both at the ridge beam as well as at the top of the wall.
Trusses serve the same purpose as rafters in that they support the weight of your roof, but they do so in an entirely different manner. Trusses do not require a ridge beam to rest upon but rather are self-contained units. Think of building trusses as pre-made triangles that sit on top of the walls.
While a truss roof is both quick and easy to install for a general framing crew, they do need to be pre-ordered well in advance. They are not built on-site like rafters, but rather must be ordered from a factory, which can take some time. Once on location, however, they go up quickly.
The fact that a truss is a triangle, with an attached horizontal member, causes it to encroach on the accessible area in an attic and prevents the option for a cathedral ceiling now or at a later date.
Both building trusses and rafters are acceptable options in residential buildings. Determining which one you choose, depends on your goals in terms of design and construction.
For more information about building trusses, contact a specialist near you.