Roof Sheathing Buckling

Asphalt shingles sometimes buckle slightly and in an irregular pattern due to moisture in a the materials of a new roofing system.

Roof sheathing buckling.

Diagnosing other roof problems. A broken sagging rafter will also cause a dip in the roof s surface. Under your shingles there is a layer called the roof sheathing. The worst area is over a full bathroom that doesnt have an exhaust fan or window and theres an attic access hole directly outside the bathroom door.

If the wood structural panels are tightly butted there is no room for expansion and buckling can occur. Plywood and osb roof sheathing are the most popular roof sheathing materials in the u s. For other possible causes. Also h clips reduce any buckling of those edges over time so they are a good idea even if not always required.

The pieces of sheathing are supposed to be spaced about 1 8 inch apart so that they have room to expand and contract as the temperature changes. Improper installation of roof sheathing panels can result in warping or buckling of asphalt shingles. This house dates back to the 60 s with 3 4 1x8 pine decking. Any ideas what might cause severe buckling of roof sheathing.

If the sheathing is properly gapped then the gaps can close causing the shingles spanning the gap to buckle. Tools you will need for roofing from amazon bostitch coil nailer https amzn to 2u1v8e2 shingle remover https amzn to 2fzu5wf roof snake https amzn to 2. But they must be installed correctly. The wetness gets absorbed by the felt underlayment causing the felt to wrinkle.

The nails slip out of the sheathing and create small visible bumps on the surface of your roof. This sheathing is generally made from plywood or a similar material. Buckling can occur if the wrong type of nails were used to connect the sheathing to the rafters. This then telegraphs to the shingles above.

If the sheathing is not gapped the sheathing itself may buckle especially with thin sheathing 24 in. The boards dont appear to have come loose at the nails but instead have cuped badly 1 1 2 2 in places. For a good reason. Plywood and oriented strand board osb like all wood products will expand or shrink slightly with changes in moisture content.

Buckling shingles can sometimes be traced back to mistakes made during roof installation even though the buckling may not show up for a year or two after you get a new roof. Apa recommends a 1 8 inch space between panel edge and end joints. They are easy to work with readily available and perform the job well. That can mean costly time consuming callbacks.

But the moisture evaporates as the materials reach equilibrium with the the surrounding air and the shingles settle back down flat. When plywood or osb sheathing picks up moisture it expands.