Moss Mess

For a good portion of North America, drought has had the land in its grips for the last two or more years.  Homeowners pray fervently for rain while watching their lawns and gardens burn to a crisp and their water bills going through the roof, or face severe water restrictions that make them have to let their lawns go completely.

For other parts of the country where rain falls in abundance, other problems exist, and one of these is the growth of moss on roofs and other surfaces. States such as Florida, Alabama, Louisiana, Georgia, Mississippi and in the northwest, Washington, Oregon and Northern California are troubled with moss  growth that can severely damage roofs and wood surfaces if allowed to grow unchecked.  Moss itself does not damage the surface…in England, moss growing on old buildings is thought by some to give them “character”.  What does damage is the wetness below the moss, clinging to the surface of roofs, causing the surface below to never dry and cause rot and eventually, holes, where it is present.  Though it is rare, the picturesque Spanish moss (which actually is a parasite)seen trailing from tree branches, can attach itself to houses and latch onto attic vents, causing them to rot in the deep South.

Roof Moss- it’s Everywhere!

The beauty of moss may be in the eye of the beholder, but if you are the unlucky homeowner whose roof has been attached by this invader, there are relatively simple steps that can be taken to rid your home of this pest.

Moss grows on shingles or tin roofs cedar shake shingles, and sometimes on brick or concrete window sills. If you see moss, remember that this means the surface beneath is soaking wet to give the moss a foothold in solid material.  To begin, assess why the moss would be there in the first place.

Moss prefers dimly lit, wet places.  North facing roof lines or places sheltered from the sun by heavy branches provide an excellent place for moss to grow. One of the first things to do if you find moss is to cut back any tree branches shading the moss by at least 6 feet.  Let the sunshine in, and the moss will  dry out and be gone.

Roof Moss Removal

To remove moss from shingles on the roof, you will need a sturdy step ladder, a 5 gallon bucket, a solution made of 50/50 chlorine bleach and water, and a sponge.  Be sure to remember all the ladder safety tips and check your shoes before stepping on a ladder…no flip-flops, wear sturdy non-slip boots.  Do not try to carry the water bucket, sponge, gloves, broom or anything else all in one trip. 

When safely on the roof, mix your water/bleach solution if you have not already done so, put on your gloves to protect your hands, and soak each moss area with the solution as applied with a sponge. Bleach will not hurt the surface of shingles or tin roofs (remember how slippery tin is, folks!).  Allow the solution to dry, overnight if possible. The next day returning with a broom will allow you to sweep off the dried moss. Difficult patches may require scraping with a wide blade putty knife. Then, inspect the area beneath where the moss was for water damage.  More repairs may be necessary if the moss has done its dirty work.  On the East coast, moss sometimes grows on expensive slate tile shingles.  It does less damage to the tiles, but also can cause moisture damage to the surface beneath.  The same clean-up methods will apply here, too.

To keep the moss from returning, bleach water works for awhile.  Also, you can call your county Agricultural Extension office for suggestions on how to stop re-growth of moss specific to your area.  They are full of good ideas and glad to help. In our area, the recommendation was to spray the affected area with Roundup herbicide, and that would retard growth of new moss for up to a year.  I would also add that it would not be a bad idea to try a test area somewhere inconspicuous before spraying tin roofs with any product, just in case, to avoid disfiguring the surface of the roof. These are the best ways to get rid of the moss mess on your roof, and enjoy the summer regardless of the weather.  

Click to learn more about Portland roof moss removal
Photo credit: Orin Zebest / Foter.com / CC BY