Prompt repair of roof damage is the best way to avoid additional costs for roof decking repair.

The shingles on your roof are attached to wood decking, known technically as “substrate”. Older decking lumber is usually tongue and groove or plank. Since the mid 1960s, most buildings and homes have decking made of plywood.

Decking construction is important because shingle manufacturers require an acceptable deck surface for the application of shingles. If the decking is not properly constructed or damaged, the shingle warranty may be voided.

Some manufacturers of high-grade shingle products insist a layer of plywood be installed over an existing board or plank deck to mitigate issues of un-even surfaces or expansion and contraction.

Deteriorated decking (substrate) is often revealed during the roofing process. If the roofing construction is timely (i.e. not years after the roof should have been replaced), selected replacement of deck board is usually enough. If the roofing is delayed, extensive replacement of wood decking may be necessary, typically because leaks in the roof have led to wood rot.

Waves or dips are usually indicators of decking problems

Beware of roofers who say they will do an extensive wood bridge to hide the rotted wood. This weak point will get worse with time, creating a safety hazard for anyone who steps on that area. In addition, the rotting wood can produce mould (a health hazard) and/or it could attract carpenter ants that create an even bigger hole by literally eating away the wood decking.