Roof Truss Bottom Chord

This creates additional surface area for the two members to transfer forces and allows for them to be plated together creating a strong resilient joint.

Roof truss bottom chord.

Roof truss uplift occurs when the bottom chord of the truss is exposed to significantly different moisture or temperature conditions than the rest of the roof truss. The horizontal beam of the triangle of a bottom chord is used in this simple triangle truss construction. For example if the bottom of the truss is buried in insulation while the remainder is in the open attic air this condition can occur. Continue reading below our video of the day.

The trusses are 42 long with a 2x10 bottom chord 3 12 pitch. Removal has left them extremely vulnerable to collapse due to spreading especially under snow loads but also under just the load of the roof itself. Those trusses were engineered with a heavy critical dependency on the bottom chords which are in tension. It is utilized in a framed roof comprised of rafters and a ceiling joist.

And the responses from the experts and my take on each one. The stability of this shape supported by the bottom chord is the reason for the common usage of the triangle truss.