Reinforcing Roof Truss Frames Under Load

Truss framed roof systems with high pitched top chords and horizontal bottom chords have a smaller weak axis moment of inertia than say a flat roof or floor joists and under shear load will tend to deflect more in weak axis bending.

Reinforcing roof truss frames under load.

Top and bottom chords in compression can buckle laterally if not braced or appropriately reinforced. These are usually accomplished during a complete re roofing. Snow increases the overall weight of your roof adding to the forces acting on your rafters. Space them four inches apart along the edges and six inches apart in the middle of the plywood sheathing.

Strengthening existing roof rafters is a difficult process that often requires professional help. Use wood adhesive underneath the sheathing along the connecting joint with the roof trusses. Reinforce your roof a properly constructed roof in areas subject to high winds has trusses attached to walls with hurricane tiedowns properly nailed sheathing and heavy duty shingles. Connect roof sheathing to the roof framing with ten penny weight common or eight penny weight ring shank nails.

Without altering the roof structure of an industrial boiler plant a long span steel truss frame was modified in place to support heavier loads. The owners of an industrial boiler plant in the northeast were required to reduce particulate emission levels from coal fired boilers. Compromised trusses can lead to severe structural problems such as bowing exterior walls sagging ridge lines and roof collapse. If dead loads must be hung from trusses then extra support can be provided by installing support beams perpendicular to the trusses reducing the span of the bottom chords and increasing their ability to carry the weight load.