To Power Wash Your Roof or Not?

Roof cleaning with high-pressure water cleaner

So your neighbor just had his roof power washed – and it looks brand new! Are you considering power washing your asphalt roof because it’s looking a little worn down? Before you do any cleaning, there are a few factors you need to take into consideration.

Staining or discoloration of shingles can be caused by the age of the roof, water drainage patterns, metal fittings on your roof (ex. antennas, satellite dishes, ventilation covers) or growth of algae or moss.

First, consider the age of your roof. Is it more than 10-15 years old? After years of sun and weather exposure, and depending on the rating of your roof, shingles will begin to curl and lose granules.  This can lead to staining and an uneven appearance.  The only way to fix shingles in this condition is to replace them.  Power washing an old roof can further remove granules, compromising the water-shedding ability of your shingles. High pressure can actually tear damaged shingles and dramatically shorten the remaining life of your roof.  Damage from power washing could result in costly repairs, definitely not what a homeowner is bargaining for.

If you have staining from a rusting fitting or cover, the first step would be to remove it and replace it.  We recommend contacting a professional when working your roof, for safety reasons and to make sure it is sealed and done correctly.  After the cause of the rust is removed, a simple solution of vinegar can be applied with a spray bottle and rinsed with a garden hose after a few minutes to remove the stain. We would recommend you contact a professional before attempting any rust stain removal yourself, and always wear the proper protective gear when applying any type of cleaner, and take safety precautions when getting on your roof.

Algae, moss or lichen growth will look like patchy white or green areas, or sometimes cover the roof entirely.  Poor drainage and shade both contribute to algae and moss growing on a roof. Moss, algae and lichen growth on the roof of your home can cause stains or discoloration, but if left unchecked can cause more serious issues. Taking care of the problem early will not only help curb appeal but extend the life of your asphalt roof. Extreme moss growth can lead to more than just a cosmetic problem, it can infiltrate the shingles and lead to curling and lifting. The good news is that both moss and algae can be removed by applying a bleach and water solution or algaecide and simply rinsing with a garden hose. This is best done on a sunny day, free of wind.  Check out this article for more information on removing moss, algae, and lichen: https://bit.ly/2KUc1XZ 

If you are still unsure about how to go about improving the appearance of your roof, make sure you do your research before attempting to make any changes. It is always best to consult a professional before proceeding with any type of cleaning and make sure to wear protective gear and use caution when climbing on to your roof.