Roof Truss Issues

Roof truss uplift can be diagnosed as the cause of nail pops and cracks or separation between the ceiling and wall top.

Roof truss issues.

Arched roof trusses moving in response to moisture temperature variations across the truss can lift the building ceiling sufficiently to cause nail pops or actual tears at the ceiling wall juncture. 3 defective lumber sometimes a knot or check in the lumber of a truss is intact and appears structurally sound when the roof is installed but pops open later. Resin dripping from the wood as in the photo below is ugly but not a structural defect. The construction concerns article dated february 13 2013 discusses the roof trusses of an 1840s grain elevator with a pitched roof shaped like a capital a.

These areas of the roof subjective to compressive forces oftentimes face roof support problems such as the truss members buckling or distort out of a plane and unless they are properly braced to hold them tight during erection the entire truss may warp up and distort out of a plane. This problem occurs occasionally with roof trusses. Because the bottom chord of the truss is buried in heavy insulation it experiences different conditions than the top chord. If the truss is bad enough it can cause the sagging or collapse of a roof.

Repairing truss uplift problems if you re building a new house inspect your trusses. Roof truss uplift occurs when the bottom chord of the truss is exposed to significantly different moisture and or temperature conditions than the rest of the roof truss. Damaged or missing gusset plate it must be intact and free of corrosion. Should a decision be made to modify a truss in order to raise the ceiling in an area allow more storage or move a stairway then it is wise to consult an engineer for assurances that there is no structural issues.

Warm moisture laden air leaking into the attic gets absorbed by cold parts of the truss expanding the wood and causing the truss to warp slightly. The upper members of the. If the drywall can t move enough to accommodate the warp it cracks away from the wall. They should not be nailed to a wall using 16 penny nails.

A broken roof truss can cause many different problems. Tim also revealed another common issue being that trusses are sometimes modified on site without approval which can affect the structural integrity of the roof and lead to major problems. Dry wood shrinks moist wood expands. This can lead to structural issues and occasionally the roof sagging.