How Wide Are Roof Truss Chords

For example a slope of 6 12 means for every 12 inches of horizontal distance the slope of the roof will rise 6 inches vertically.

How wide are roof truss chords.

Box 177 la crescent mn 55947 507 895 8400. The king post truss with extra bolsters builds on a favorite timber frame truss design with two added bolsters on the underside of the bottom horizontal chord for a heftier look. If we go any larger it will require more webbing inside the truss which will directly affect the cost of the truss. The rise will be the elevation change over the 12 inches.

This 26 span truss with a 4 12 roof pitch is the most economical truss we can build. Most economical when the difference in slope between the top and bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. Some of the commonly used types are shown below. Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge.

The run or the base number is 12 inches. The bolsters can have a wide variety of decorative profiles cut into their visible ends. Each can vary in overall geometry and in the choice of the individual elements. These steel joints are needed to support the overall truss.

While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses. 500 sycamore street p o. Its conventional triangular truss design is that the two sides are sloping up to the apex above with the struts known as the upper chords leading down from it. Keep in mind that the higher the pitch the steeper the roof.

The dimensions of your structure will determine the angles formed by the truss s top and bottom beams or chords. Just as there are many types of roofs with many roof parts there are many different types of roof trusses this extensive article explains through a series of custom truss diagrams the different truss configurations you can use for various roofs. The same is true if we make it steeper. A truss for a gable roof on one side of your home for example might need to be 15 feet 4 6 m long and 4 6 feet 1 2 1 8 m tall.

The more complex the truss framework is the greater quantity of these joints will be required. Under gravity loads the top and bottom chords of the truss provide the compression and tension resistance to overall bending and the bracing resists the shear forces. Typically the upper chords have different lengths in this particular type of truss that make the apex off center. These are attached to the horizontal beam thus making up the triangle s base.

Steeper roof pitches require longer webs which add to the cost. Flat the most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7 of the span in inches.