Some houses with open cell spray foam installed on the underside of the osb roof sheathing have had moisture problems.
Roof sheathing problems.
If these problems are widespread it s a sure sign that you need to call a roofer.
Try to correct this problem.
A sagging ceiling is another clue that there are major problems with a roof s sheathing.
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.
If the insulation becomes damp it will lose some of its insulating values.
Eventually the fascia soffits and even the roof sheathing will rot.
But where does the moisture come from.
One of the most common signs that a roof s sheathing is damaged is a roof leak.
If you have gutters but no gutter apron to stop the water it will wick behind the gutter.
When water flows off the edge of your roof some of it clings to the underside of the shingles and dribbles toward the fascia.
Waterlogged roofing materials and sheathing will bend and bow creating dips or making a ceiling take on a convex appearance.
Such leakage can lead to the development of mold and mildew within a home.
A broken sagging rafter will also cause a dip in the roof s surface.
You might find holes left over from a satellite dish or antenna mounting brackets or just about anything.
If you are unable to pop a chalk line across the rafter tails and trim them with a saw before attaching the sheathing.
The nails slip out of the sheathing and create small visible bumps on the surface of your roof.
This is crucial because this building line will be a very noticeable when viewed from below.
Water spots may appear on the ceilings of the living spaces.
Solutions to roof buckling.
In addition a leaking roof is more prone to collapse as well as the formation of large gaps and holes.
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.
Moisture can lead to mold which is both unhealthy to the occupants of the building and can rot the ceiling framing or wall assembly.
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.
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.
Buckling can occur if the wrong type of nails were used to connect the sheathing to the rafters.
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.
The osb got wet and rotted.
Condensation on the underside of foil backed osb can cause several problems.
