Attic Plywood Wet

If you suspect you have moisture problems in your attic check for the following indications of excess moisture in the attic.

Attic plywood wet.

Buckled or damaged roof sheathing. Most attics are dry plywood is a smart vapor retarder with variable permeance. Wet sheathing was found in attic area due to lack of venting. The insulation was contaminated and we inspected the attic side of the ceiling drywall below for signs of leak stains or mold.

In this photo of very dark mold in an attic in a wet attic mold which we found to be brown in the microscope looked black on the plywood. Black mold in attics. Water in your attic can damage wood beams insulation and even. In the vast majority of cases the mold growth is caused by condensation.

Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green. Moist or wet insulation. Though attics are typically hot and dry a leaky roof or pipe condensation or severe weather can cause water to enter your attic. Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.

Often this is first noticed when re shingling. There are many signs that an attic is wet. If any moisture makes its way to the plywood the damp plywood will dry out on hot sunny days. It s not a vapor barrier.

It is never a good idea to install a roof over wet plywood or any type of roof sheathing. Moisture or frost on the roofs sheathing. This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. The black attic mold shown here confirms that this attic had a serious venting and moisture problem including moisture from sources lower in the building.

Water or drip marks scattered on the attic floor. If you have ceiling leaks only in the spring it may be that ice has been forming on the sheathing all winter and it suddenly melts when a warm spell arrives. Moisture frost and ice buildup on roofing nails. The mold itself may have a cottony texture but can also be velvety leathery or.

If your insulation particularly the cellulose on top is uniformly damp over much of the area then pretty certain it is condensation or frost forming which is not uncommon at all even in ventilated attics when the outside temp gets below about 15 or so.