How To Clean Your Roof Of Algae Stains

Posted on: 28 July 2015


Algae stains are ugly. They create dark streaks that go across your roof and cause it to not blend with the rest of the house. This is very frustrating for homeowners because it can lower a house's overall worth. As a result, many homeowners are taking the war against algae into their own hands by cleaning the algae themselves or hiring a roof repair contractor to do it for them. If your roof needs any other repairs, contact a roofer like Golden Spike Roofing Inc. If you choose to clean your roof yourself, here are the steps that you need to follow.

1. Choose the Correct Day

First, you are going to want to choose the best day to clean your roof. Preferably, you would choose a cloudy day that doesn't have a high chance of rain in order to avoid the direct sunlight that would result in your cleaner being absorbed too quickly.

2. Mix the Solution

Take a large bucket that is able to hold at least a gallon and a half of liquid. Fill it with one gallon of water. Then, add a quart of bleach and another heavy duty cleaner. Your best bet is going to be to use trisodium phosphate, or TSP, because it is guaranteed to not create a poisonous gas when mixed with bleach. Avoid cleaning products with ammonia.

Once your solution is ready, put it into a spray pump and attach the nozzle.

3. Spray the Roof

Get on your ladder and gingerly make your way up to the roof. Start spraying down your roof, taking particular care to douse any areas of the roof with algae. Keep refilling the sprayer with your cleaning solution until the entire roof is soaked. If you were able to choose a cloudy day, wait fifteen minutes. If it is a sunny day, wait until the liquid on top of the roof has dried. If it took at least fifteen minutes to dry, then you are done. If it took less than fifteen minutes to dry, perform the task again and wait for the cleaner to dry again.

4. Rinse the Roof

Next, rinse the roof with a hose until all of the cleaner is gone. You should see the algae come off the roof with the cleaning solution, since the bleach and chemicals in the solution weaken its hold on the roof.

If you performed these steps and were not able to remove all of the algae, either run through this series of steps again or call a company that specializes in roof repair.