My Attic Insulation Is Wet
Be sure to take the necessary steps to prevent water damage to your home.
My attic insulation is wet. The typical expected cause is water penetration from the exterior due to a defective roof covering. Cmhc s information piece asbestos provides additional guidance. It will need to be replaced immediately as it will lose its effectiveness to keep your home comfortable. If you believe moisture is a problem in your attic go and inspect it for signs of mold and mildew.
Issues such as blocked vents a leaking roof or even basement flooding can cause attic insulation to get wet. Small black and or greenish colored dots on insulation boxes or other materials is a sign of an exceedingly high moisture content in the air. Loose fill vermiculite insulation may contain small amounts of asbestos and you should consult a professional if it is going to be disturbed. The best solution for controlling moisture is at its source.
If the fiberglass within your wall cavity or in your attic becomes wet from a leaky roof or burst pipe it will lose insulating effectiveness until the material dries out over time. Box out light fixtures. If you find vermiculite insulation in your attic do not disturb it. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.
Trapped moisture encourages corrosion of roofing fasteners and rusting of steel studs and wall ties which reduce wind uplift ratings. Though attics are typically hot and dry a leaky roof or pipe condensation or severe weather can cause water to enter your attic. These can include installation of seamless gutters and downspouts. Wet insulation means trapped moisture that will slowly degrade the entire roofing system from the decking to the building itself.
A moist attic means moist insulation and moist insulation is less effective. A roof timbers within an attic can become damp from two sources. If the problem is the result of water or moisture penetrating the foundation or floor slab there are many remedial actions which may help. If insulation becomes moist or damp its rendered useless.
Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be.