What Can I do to Remove Moss from My Roof?

August 21st, 2014


Quick Roof Repair

Moss is a common plant species that tends to grow in moist, cool areas.  Indeed, any damp environment can be the perfect place for moss to grow, and this includes your roof.  Moss is very bright green in colour and features small leaves, but it does not have a root system.  Moss grows well on many types of surfaces, including hard surfaces, and really just requires moisture and/or humidity to grow.  When moss appears on your roof, you need to take action as this seemingly harmless plant can compromise the integrity of your roofing structure.

Removing moss may be challenging.  First and foremost, because moss grows well in shaded areas, you’ll want to remove any sources of shade.  Overhanging branches or large trees around your roof were block the passage of sun and ultimately promote moss growth.  Trim back tree branches and remove other plans or bushes that block the sun and you may find your moss problem is solved completely.

You can also attack moss by making your roof environment more acidic.  Many household cleaning products have an acidic pH, and they are very effective when it comes to killing moss.  Even products such as vinegar, orange juice, lemon juice, or tomato juice are acidic enough to kill moss.  While it is recommended that you dilute these substances to prevent corrosion, many of them can be applied directly to moss to stop its growth.

Another way to remove moss is to make its environment a base.  Typically, moss grows best in a pH environment between 5.0 and 6.0.  By increasing the pH, you can effectively kill the moss.  Again, many common household products make an effective treatment including baking soda, baking powder, salt, ammonia, soap, and bleach. 

There are also many things you should never do to remove moss.  Your roof is an integral structure in your home, and you need to maintain it.  More importantly, roofing repairs or replacements can be exceedingly expensive, so your moss removal techniques should not compromise your roof and roofing structures.  Never pressure wash moss from a roof as high powered water also damages asphalt shingles, thereby diminishing the quality of your roof.  Similarly, you shouldn’t scrape moss from your roof to avoid unnecessary damage to shingles.  Also, take care whenever you attempt to adjust the pH of your roof.  Strong acidic or basic mixtures may be corrosive and destroy your shingles. 

Also, remember that roofing can be a dangerous endeavour, and if you’re not confident in your abilities, you should always hire a qualified professional.  Before venturing onto your roof to clear away the moss, ensure you have the proper safety and cleaning equipment; or, air on the side of caution and bring in a professional to do the work.