Pros and Cons of Rafters and Trusses

Rafters

The traditional way of supporting a roof is by has been rafters- Also known as "stick framing- cut, built and installed on site by an expert carpenter. Rafters are made from sloped framing boards of dimensional lumber -- usually 2x8s or 2x10s -- connecting the roof peak, known as the ridge board, to the plates of the exterior walls. They are secured at the bottom by ceiling joists. Collar ties, placed horizontally halfway down the rafters, hold the rafters and roof planes together.

While rafters are less frequently used today because they cost more compared to trusses, there are certain advantages to the former. Stick framing is a lot more flexible and may be altered without effecting the structure. As a result, you can create open space under the roof, valuable for either good looks or aesthetics or for practical purposes such as building an extra room. It is also simpler to accommodate a home addition with rafter roofing.

While the installation process is slower than for trusses, rafters require a shorter lead time to get ready, so if you are in a hurry, rafters will be the quicker way to go overall.

Trusses

Trusses are lightweight engineered units consisting of top and bottom chords supported by a webbing of lumber in a triangle shape. Because they are pre-assembled to your building specs offsite, often using automation such as computer-driven saws, they are much faster and more economical to install than rafters. Although they make use of smaller (and therefore cheaper) pieces of lumber linked with tooth plate connectors, trusses are very strong and stable, capable of spanning distances of as much as 60 feet. This reduces the need for interior load-bearing walls and allows for a more open floor plan, in tune with today's trends, on the stories below.

Another plus offered by truss framing is that it saves an important natural resource by utilizing smaller amounts of lumber and producing less wood waste.

However, truss systems do come with some disadvantages. The pre-built truss system is heavy to transport and lift into place. You are likely to need an 18-wheeler and a crane -- together with adequate road access -- for the job.

Once a truss system has been installed, it will be difficult and even dangerous to try to modify it. Cutting any part of the webbing or even drilling a hole to accommodate electric wiring can undermine your truss roof's integrity. You'll need to consult a professional building engineer if you must make alterations. So Cedar Hill Roofing in new construction should take this into account when doing a roof.

Also, recently, the National Fire Protection Association has raised concerns about the fire safety of truss-framed roofing made of engineered wood.