On occasion poor attic ventilation can cause the sheathing to become warped from underneath.
Roof plywood buckling.
Ripples or waves on the roof surface are a sure sign that the shingles or decking has probably buckled.
If the wood structural panels are tightly butted there is no room for expansion and buckling can occur.
Such buckling may occur between supports or between nails along supports.
Roofs buckle because either the roofing underlayment has wrinkled or the wood deck itself has shifted for some reason.
Apa recommends a 1 8 inch space between panel edge and end joints.
But they must be installed correctly.
These ventilating systems work in conjunction with adequate soffit ventilation.
However a more pronounced buckling in a line running up the roof like in the photo above is caused by buckling of the edges of the plywood or osb roof sheathing due to water intrusion or extremely high humidity in the attic.
Your builder is responsible for providing adequate soffit ventilation.
Occasionally the buckling is caused by poor workmanship wrong materials or possibly by a problem with the structure itself.
Call your builder and have him fix the buckled plywood.
This happens most often in hot and humid climates.
If the adhesive side is not laid properly and not applied flat it will surely show its buckling through the roof shingles.
For a good reason.
They are easy to work with readily available and perform the job well.
However warped plywood sheathing means the entire roof has to be replaced immediately or it may collapse.
When plywood or osb sheathing picks up moisture it expands.
Buckling of wood structural panel sheathing such as plywood or oriented strand board osb occasionally results when increased moisture conditions cause the wood to expand.
Plywood and oriented strand board osb like all wood products will expand or shrink slightly with changes in moisture content.
Improper installation of roof sheathing panels can result in warping or buckling of asphalt shingles.
If the sheathing is properly gapped then the gaps can close causing the shingles spanning the gap to buckle.
Your roof decking is the plywood sheets that cover your home.
Continuous roof vents stationary roof vents turbine vents and power attic ventilators are just a few.
The most common cause appears to be movement in the roof sheathing with changes in moisture levels.
When these boards are not properly fastened and nailed to the framing they can buckle as well.
