Category Archives: Roof Moss Removal

Algae Resistant Shingles: An effective way of moss and algae control.

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Many homeowners have had their roof fall victim to unsightly algae and moss . This is a common occurrence in areas that experience high levels of humidity. Aside from high humidity, algae can also be carried to your roof through airborne spores. Seattle is located in the national danger zone for roof moss and lichen. Fortunately, today’s homeowner has the option to choose algae resistant shingles, also known as AR shingles, to avoid this problem.

The History of Algae Resistant Shingles

Algae resistant shingles date back to the 1980’s when roofing materials were produced that contained alternative kinds of mineral granules, such as:

  • Zinc
  • Copper
  • Galvanized Metal Powder

When AR shingles were first produced in the 1980’s, they were considered to be a premium option in roofing materials. By the 1990’s, algae resistance became a standard option and was available in most brands of shingles.

How Do Algae Resistant Shingles Work?

AR shingles work by using copper that is included in the roofing granules that make up the shingles. The copper is not noticeable to the eye; however, it will keep algae from being able to survive on the surface of your roof. The copper or zinc materials found in AR roofing materials also respond to rain which activate the algae fighting action. Moisture generally works to help promote the growth of algae, but with these special shingles, it helps to further protect the roof.

AR shingles tend to be more expensive initially, but when considering the cost of having to have the algae removed from your roof on a yearly basis, they are well worth the initial investment and will help to protect your roof for many years to come.

How Effective Are Algae Resistant Shingles?

Some brands of algae resistant shingles can help keep your roof free from unwanted moss and algae for up to 20 years. Products containing copper have been reported to be ten times more effective than zinc at keeping algae at bay. The copper is generally time released and will work to resist algae and moss build-up over a long period of time.

It is also important to note that adding some type of copper ridge or hip shingle containing copper will not work on an existing roof system that already has live algae or moss present. It will not kill the algae, but rather works to provide resistance to it before it starts.

No one wants to think of fungus taking over their roof, causing damage as well as ugly staining. In choosing algae resistant products when replacing a roof, you may be spending more money upfront, but for the protection and peace of mind that comes with it, it’s worth it.

Methods of Seattle Roof Moss Removal

roof cleaning shoreline

WHAT EXACTLY IS ROOF MOSS? 

what is roof moss icon Bryophytes are soft plants that grow in mats and clumps. They reproduce through periodic release of airborne spores. They have no vascular system to feed themselves as plants with roots do. Bryophytes therefore grow where moisture is prevalent.

The Seattle region with between 72-88 days of sunshine a year is an inviting environment for moss growth. Our lack of sun is the reason moss grows so heavily in the area. With no ability to control our amount of sunshine, we are left to do periodic maintenance.

DAMAGE CAUSED BY MOSS

CEDAR DECK RESTORE AND ROOF CLEANING 013Over 10,000 roofs are replaced per year due to water intrusion, in the Seattle area.Lack of Seattle Roof Moss Removal is a major contributing factor to the number of roof replacements. Moss grows in patches 1-3 inches wide.

Homes with infrequent sunlight or under foliage are the most prone to moss growth. Large patches of moss trapping moisture in 1-3 inch mats create water dams that then begin pushing water underneath roofing substrate. The roofing material is never left to dry out.The consequences  of not performing a Seattle Roof Moss Removal are:

  • Rot.
  • Mildew
  • Buckling

METHODS OF MOSS CONTROL 

You can speak to any 2 roof cleaners in the country and the proper method for roof cleaning and moss control is always up for debate. There are standard methods of moss control practiced around the country these methods are:

  • Power washing to remove moss.
  • The use of zinc strips.
  • Chemical treatment.

 POWER WASHING

never power washPressure washing without adequate chemical treatment afterwards is the least effective method in killing moss. Without the use of a moss inhibiting chemical you’re left with a roof that will need another cleaning almost immediately.

There have been several studies done on the damage a power washer can do to asphalt granules.  ARMA [Asphalt Roofing Manufactures Association] recommends not using a pressure washer on asphalt shingles for roof moss removal.

Their primary concern is the loss of granules. Although not as good on asphalt shingles, a power-washing is probably the only effective way of properly cleaning cedar and metal roofs.

ZINC STRIPS

DO ZINC STRIPS WORKZinc Strips are effective means of containing moss growth. Due to the cost and the amount of coverage required to kill moss, many times it is unfeasible to use this method.

For Zinc strips to successfully control moss growth they must be placed every 3 feet from the tip of the roof to the gutter line.

This method is very unsightly and many homeowners do not like the look of Zinc strips going down their entire roof line. The picture above shows CLEARLY, that zinc and metal DO stop moss from growing. Where the metal vents are present; no moss is growing directly beneath them. To effectively use zinc strips:

  1. Two inches of zinc should protrude the asphalt shingle.
  2. They should start at the ridge cap and end 3 feet above the gutter.

CHEMICAL TREATMENT

Chemically-Cleaning-a-Roof-SeattleChemical treatment, also called soft wash roof cleaning, in our opinion, is the most effective means of moss control. Using the right chemicals, completely kills all moss spores and prevents new moss from rebuilding.

 

CLICK FOR COMMON SOFT WASH CHEMICALS

 

Most soft wash roof cleaner’s offer warranties of 1-5 years, they are secure in offering these warranties because they know that it took years for this moss to grow on your roof and it will take years for it to grow back, provided the right chemicals are used in strong enough doses. We make Seattle Roof Moss Removal Last!

The decision on what method is the right method for Seattle Roof Moss Removal is always up for debate. PWNG uses the chemical soft washing method to soundly control moss. We stand by our service and offer a 1-year warranty with every Seattle Roof Moss Removal. We look forward to any comments or questions our readers might have and we welcome an open discussion on roof cleaning. 

Roof Cleaning FAQ

[frequently asked questions]

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Why is there still moss on my roof?

Your roof was not power washed, depending on your roof slope we either (a) manually scrubbed large patches with a stiff bristle brush or (b) chemically sprayed your roof and allowed Mother Nature to take its course.

How long does it take for the moss to come off my roof?

Dependent on the weather and sunlight conditions 3 days to 3 weeks. Your roof was sprayed with a mixture similar to weed killer. We live in a very moist climate and at times sunlight is infrequent.[i] After spraying your moss it is left moist and wet on your roofing. Its roots are dead immediately. Sunlight dries your moss out and then rain washes it down your gutters. Hoping to be as cautious as possible to your roofing, our process isn’t immediate. [ii]

What was sprayed on my roof?

A mixture recommended by ARMA to be the safest possible way of cleaning asphalt shingles. This is the method your shingle manufacturer recommends for roof cleaning. You can see the PDF by clicking here. [iii] We added Borax-Lo [iv] that keeps moss from returning.

Is this bad for my plants?

Yes and No. We’ve taken every precaution to protect your plant life by not over spraying past your gutter line and washing down any plants that were touched with our chemical. Simply put we are at your residence to kill a plant and there is not a green way to do that. If we damage any plant life we will do our best to resolve the situation with you.

How long does the process last?

You are covered for one year from the day you hired us[v]. Many of our customers have reported no moss growth for 2-3 years and as many as 5! The information we have garnered has helped us create a chemical blend that works. There are over 10,000 roofs a year who fail due to moss in our area. Wet and damp moss locks and holds moisture on your roof. Large patches create a dam and the shingles underneath begin curling and swaying. We have done as much as possible to protect your roof from damage during cleaning and have made moss growth very inhospitable. Thank you for choosing us. We look forward to keeping you as a happy customer for years to come.

 

References


[i] http://en.wikipedia.org/wiki/Seattle
[ii] http://pwngservices.com/2012/08/10/soft-wash-roof-cleaning-seattle/
[iii] http://pwngservices.com/wp-content/uploads/2014/11/ARMA-BULLETIN.pdf
[iv] http://pwngservices.com/wp-content/uploads/2012/06/borax-10-mol.pdf
[v] http://pwngservices.com/wp-content/uploads/2012/06/ROOF-CLEANING-WARRANTY.pdf