How to Remove Mold From Your Roof

Posted on: June 27, 2017

Worried about mold or slime that you’ve spotted on the roof? In the humid Mid-Atlantic climate, it’s quite common for various stains and growths on roof shingles. Algae and moss are by far more common than mold, but any of these should be dealt with to preserve your roof’s health and good looks.

First, let’s identify what is really on your moldy roof:

  • Algae: the slimy green, black, or blue-green streaks
  • Moss: a vibrant green plant growth that covers the roof
  • Mold: various colors, often in numerous round spots, usually infested from within the attic

How to Clean Mold, Algae & Moss from a Roof

If mold has grown on your roof or underneath the shingles, you will find more than just exterior stains. Get an attic mold inspection to determine the extent of the damage.

However, we find algae or moss 99 times out of 100 when people call us about roof mold. This is especially true when the mildewy stains are on the north or west of the house (a quirk due to the earth’s tilted axis).

Cleaning your roof requires getting on top of it in a harness, so most people will want to call a roof repair company for cleaning and to make sure the roof underlayment is intact.

If you do want to climb aboard and clean mold, algae, or moss from your roof, here are the cleaning solutions to use:

  • Hose with nozzle or wand — not a pressure washer, because that will damage the roof
  • 50/50 mix of bleach and water — Let sit for half an hour and rinse
  • Trisodium phosphate — Add 1/2 cup per gallon of bleach & water solution for a stronger cleaning
  • Oxygen bleach cleaners — If concerned about runoff harming your garden or lawn, use an oxygen bleach instead of laundry bleach
  • Readymade cleaners — Brands include Wet & Forget, Defy, Concrobium, and Simple Green; read labels and instructions to make sure you have the right product!

Prevent Roof Mold & Algae

Keep out moisture, and mold cannot grow. Roof waterproofing may be the best solution for your needs if you are constantly dealing with mold growth.

For algae and moss, we can add metal strips of copper to the peaks of your roof. Copper is like Kryptonite for algae and moss. When it rains, metal molecules get spread around the roof for ongoing protection.

You should also keep the roof clear of debris and always make sure your gutters are in great working order so water can drain.

About time for a roof replacement? Choose shingles with embedded copper granules.

Roof Repair in Baltimore

Pause for a moment before climbing up on your roof—it’s not a project for everyone. Stained roofs may be damaged underneath the shingles, in which case you will need roof repairs anyway. For help with cleaning and repairing a roof with mold or algae, contact the best roofing company in Baltimore to take care of the job professionally.