Roof Sheathing Problems

Moisture can lead to mold which is both unhealthy to the occupants of the building and can rot the ceiling framing or wall assembly.

Roof sheathing problems.

This is crucial because this building line will be a very noticeable when viewed from below. The problem exists because nail sizes and spacing used to attach the sheathing to the roof s structural members rafters or trusses do not provide enough strength to keep the sheathing on during. When water flows off the edge of your roof some of it clings to the underside of the shingles and dribbles toward the fascia. Tiny holes in shingles are sneaky because they can cause rot a leaky roof and other damage for years before you notice the obvious signs of a leak.

While you re in the attic scan the underside of the roof sheathing for any new signs of water staining since the last inspection as well as any soft or moist spots which tend to show up after a heavy rain. If you are unable to pop a chalk line across the rafter tails and trim them with a saw before attaching the sheathing. Waterlogged roofing materials and sheathing will bend and bow creating dips or making a ceiling take on a convex appearance. And exposed misplaced roofing repair nails should be pulled and the holes patched.

A sagging ceiling is another clue that there are major problems with a roof s sheathing. Some houses with open cell spray foam installed on the underside of the osb roof sheathing have had moisture problems. If these problems are widespread it s a sure sign that you need to call a roofer. You might find holes left over from a satellite dish or antenna mounting brackets or just about anything.

Condensation on the underside of foil backed osb can cause several problems. Without proper air flow moisture can build up behind the home s exterior siding and supporting structures cannot dry out creating mold and deterioration problems. The osb got wet and rotted. The authors of the first paper cited a study in south carolina where the relative humidity in the attic was way too high in summer 80 to 100.

The importance of roof pitch photo by julian wass. Solutions to roof buckling. Faulty durability as home construction has evolved throughout the years we have seen sheathing methods change from boards to plywood to oriented strand board osb. If the walls are crooked the rafter tails will also be crooked.

In addition a leaking roof is more prone to collapse as well as the formation of large gaps and holes. Water spots may appear on the ceilings of the living spaces. One of the most common signs that a roof s sheathing is damaged is a roof leak. Try to correct this problem.

If the insulation becomes damp it will lose some of its insulating values. A broken sagging rafter will also cause a dip in the roof s surface. If you have gutters but no gutter apron to stop the water it will wick behind the gutter. Buckling can occur if the wrong type of nails were used to connect the sheathing to the rafters.

But where does the moisture come from.