IT CERTAINLY LOOKS LIKE MOLD
Maybe you poked your head up into the attic lately and then quickly closed the attic hatch in horror after seeing what appeared to be mold all over your attic insulation. Or perhaps you went into your attic a few years ago and have been afraid to go back up there again after noticing mold growing on the insulation.
You may have been trying to ignore that nagging voice in the back of your mind that is telling you an expensive attic mold remediation is in your future. Before you panic, there could be another explanation that will put your mind at ease.
WHAT ELSE COULD IT BE?
Many times discoloured insulation is actually the result of dust… not mold. Anywhere that insulation is in contact with a thermal bridge, an area where cooler air comes into contact with warmer air or surfaces, or unintended airflow then there is going to be dirt and dust filtered through that insulation. Dirt and dust leave a residue on the insulation that can look just like mold to the untrained eye. Although ominous looking, the discolouration below is actually an area of thermal bridging and air filtration and not mold at all.
NOT MOLD AFTER ALL?
Energy auditors often appreciate the tendency for insulation to become discoloured from air filtration as it tells them exactly where the problem areas of energy loss are in an attic.
A significant air leak can be located within minutes of looking around an attic because of this. Often these leaks occur at thermal bridges but can also be present anywhere that electrical wires or pipes run through the walls. Very often the issue is a ventilation duct that is improperly sealed. Any fiberglass insulation that is exposed to an air leak will eventually turn grey or black due to the dirt and dust in the air passing through the insulation.
SO I CAN JUST FORGET ABOUT IT THEN?
Not necessarily; even though it may be a huge relief to discover that what you ‘thought’ was mold in your attic insulation is only dirt and dust, these are still organic substances. Once you add moisture to an organic substance, mold can develop and spread to other surfaces in your attic.
The long and short of it is that you still want to deal with the issue by sealing off air leaks and replacing any discoloured insulation. This will avoid creating an environment that is conducive to mold down the road.
HOW CAN I FIX THIS MYSELF?
If you locate an area of insulation that appears to be discoloured with filtered dirt and dust, dig down and you will most likely find an area where air is leaking out. Once you find the source, the solution is easy. Just use some spray foam or caulking to seal the holes and ensure the area is air tight.
It is always safest to discard the dark areas of insulation to prevent any fungal growth if moisture develops in that area in the future. Any dark areas that appear slimy have already developed mold growth and should definitely be removed. Affected areas can also be treated with Concrobium to encapsulate and stop further mold growth. .
