Your Roof vs. Mould: Tips and Tricks for Eradicating Mould Growth

You probably feel a sense of pride when you look at your home's exterior. You've meticulously maintained your lawn, mulched your flowerbeds, and pruned your trees. You've also gone above and beyond the typical homeowner and cleaned your home's siding. Now your home looks picture perfect.

Or it does below your roofline. As you inspect your yard, your eyes inevitably travel to your roof, and you notice a strange discolouration there. As you squint at it, you come to an unpleasant realization. You have mould growing on your roof, and it looks awful.

Identify, eradicate, and recover from this mould infestation using the information below.

Tips for Identifying Mould

A discolouration on your roof can come from several sources. Many may look like mould, but some could indicate a different intruder:

  • Algae: Like mould, this organism also likes to grow in damp, shady places. They have a greenish-black, streaky appearance. They may just appear black on your shingles. And because they retain moisture, they may make your shingles, gutters, and other roof parts deteriorate.
  • Moss: This organism also likes to grow in the same conditions as mould. However, you can distinguish it because it'll look slightly bushier. It'll also rot your shingles.
  • Mildew: This organism has the most similarity to mould, and it usually has a powdery consistency. It occurs in pink, red, green, or black.
  • Mould: Unlike mildew, mould typically has a fuzzier appearance. It won't stand up off the roof as much as moss, but it will have some shape. Common colours include black, brown, blue, and green. It can also occur in a slimy black film—this indicates toxic mould that could make you and your family sick.

Mould and other organisms grow on your roof either because of poor drainage or because of a leak. If you have a leak, the mould could grow in your attic as well. Inspect your attic and see if you spot any of the following common house moulds:

  • Stachybotrys: Remember the black, slimy, toxic mould we mentioned before? It can grow both inside and outside your home.
  • Aspergillus: You'll see this mould most often on rotting organic materials, like wood shingles or beams. This mould comes in blue, green, yellow, gray, brown, and black. You'll know it by its downy texture.
  • Fusarium: This mould also likes to grow on organic material, including algae, wood, and carpet. It can grow all over your roof and attic. You'll know it by its white, tan, salmon, yellow, red, or even purple colour.

If you spot mould in your attic or on your roof, you'll need to eradicate it as soon as possible. Mould can cause allergy symptoms in mild cases, but it can cause disease and even cancer in severe cases.

Ways to Eradicate Mould

You can probably eradicate the mould in your attic by yourself, but you'll need help clearing it off your roof. Call your roofing contractor to see if he or she provides mould removal, and schedule the next available appointment. Your roofing contractor will also use this opportunity to repair the leak or the poor drainage that caused the mould growth.

However, you'll still have to tackle the mould in your attic. To remove mould, take the following steps:

  • Identify the mould. If it doesn't produce harmful mycotoxins (Strachybotrys and some species of Aspergillus do), then you can handle removal by yourself. You should call a professional cleaner to remove toxic moulds.
  • Put a cloth or mask over your mouth and nose so you don't inhale spores.
  • Dilute bleach in a solution of two parts water to one part bleach. Put the solution in a spray bottle.
  • Spray the mould and let the solution sit.
  • Wipe and scrape the mould away. Put the mould residue in a sealed plastic bag before throwing it away.
  • Sterilize and dry the area.

You should also put an air purifier in the attic to catch and kill any remaining spores that might float through the air.

Strategies for Making Repairs

Mould can wreak havoc on a roof and attic. It absorbs nutrients from the roofing materials and sends spores into every microscopic crack it can find. The mould can expand those cracks and break materials apart.

You don't want this to happen to your roof, but if you don't catch mould quickly enough, you'll need to schedule repairs. Repairs could include:

  • Replacing mouldy shingles. This shouldn't cost you too much.
  • Replacing mouldy roof supports. This will cost a little more, but it merits the expense because it will help your roof last longer.
  • Replacing mouldly insulation and sheetrock. You won't have to empty your bank for this repair either.
  • Replacing your entire roof. Sometimes mould can compromise your entire roof's structure, which means you'll need a new roof. Don't worry—you'll find the replacement well worth the expense.

Regular roof inspections and maintenance can catch mould infestations before they ruin your roof. If you think your roof might have mould on it, call your roofing contractor in Calgary at Century Roofing to eradicate it and begin the repair process today.