The two most common types of insulation fiberglass batts and blown in cellulose loose fill are vulnerable to attic water damage in two specific ways.
Roof leaked all attic insulation got wet.
Musty smell in the attic.
Wet insulation no longer performs its primary function of inhibiting heat transfer.
There are many signs that an attic is wet.
Often this is first noticed when re shingling.
My spray foam insulation is wet.
If you have closed cell spray foam insulation that s been exposed to moisture never fear.
Insulation in the attic is often the first victim when roof leaks occur or when plumbing pipes routed through the attic leak.
Saturated insulation typically loses at least 40 of its insulating r value.
When insulation is wet or even just damp it no longer works to regulate the temperature in your home.
When a leak allows water to seep in through the outer membrane and saturate the insulation below that moisture can deteriorate the roof on multiple fronts.
Closed cell spray foam insulation provides a moisture barrier and an air tight seal.
If the roof has leaked it likely got the insulation wet.
While in your attic inspect the insulation as well.
During installation each skylight essentially creates a big hole in an otherwise uniform roof surface.
Loss of insulating value.
Insulation sits just below the roof s membrane.
However a burst pipe or roof leak may dampen cellulose insulation installed in your attic exterior walls or crawlspace.
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.
If the insulation became wet from water that contained any contaminates such as flood water and sewage then the affected insulation and the wallboard are likely ruined and both materials need to be removed as soon as possible.
No matter how well your skylights were installed it is still possible for them to leak during heavy rains.
Skylight leaks in heavy rain are a common source for roof leaks.
While your roof is being repaired or replaced the decking can be easily lifted to allow for blow in insulation to be shot up through a tube into your attic creating little disturbance and no mess.
When your insulation is inundated with water you need to act quickly.
Wet insulation increases the burden on the building itself and over time can lead to warping and other structural damage.
Especially as your home ages a bit.
Prolonged wetness will rot out the roof sheathing.
If you re noticing water on your spray foam insulation it almost certainly means that you ve got a leak somewhere.
A roof repair or replacement is the perfect time to replace your insulation.
What to do about a wet attic.
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.
Here s what happens if cellulose insulation gets wet and how to handle it.
