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

Leave a comment

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.

Advertisements

Soft Wash Roof Cleaning Seattle

Leave a comment

Chemical Roof Cleaning

Soft-washing involves the use of chemicals to clean roofs. This method is employed to lessen the amount of damage caused by power-washing. Power-washing on average removes 3-4 layers of granules per cleaning . A roof is known by its years of life:

  •  A 20 year roof has 20 layers of granules.
  •  A 50 year roof has 50 layers of granules.

The soft-wash method when used properly is far more beneficial to roofing substrate then power-washing. No granule loss happens when chemicals are sprayed on your  roofing. Additional benefits include:

  • The elimination of all moss spores that cause moss to grow in the first place.
  • A much longer lasting finished product; on average the process lasts 2-3 years

ARMA [Asphalt Roof Manufacturers Association] recommends soft-wash cleaning for proper roof maintenance. ARMA is the association that governs the making of asphalt shingle roofing. They are the leaders in the industry in the production and proper cleaning methods of roofing materials.

The difference in the finished look of the product : power-washing versus chemical cleaning is nearly indistinguishable, when the proper chemicals are used. A soft wash roof cleaning company generally use a few standard chemical products:

  • TSP [trisodium phosphate]. Known for its ability to remove algae and rust stains
  • Sodium Hydrochloride 10% or higher: known for its ability to kill moss and clean shingle.
  • Borax Lo: A soap like product known to aggressively kill weeds, spores and moss residual.
  • Isopropyl Alcohol: used when aggressive moss has been growing for long periods of time.
  • Surfactant:  used to slow the mixtures path down to the gutter line.

When mixed properly these chemicals generate a long lasting safe products to roofing material. These chemicals are not readily available to the average consumer and the mixtures of this chemical call for exact amounts for a strong enough product. The procedure of soft wash roof cleaning in Seattle is best left to a professional roof cleaning company.

 

Methods of Roof Moss Removal in Seattle

Leave a comment

Over 10,000 roofs are replaced per year due to water intrusion, in the Seattle area. Roof Moss 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 are:

  • Rot.
  • Mildew
  • Buckling

What is Roof Mold?

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.

Differing 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 

Pressure 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.

The metal roofing vent prevents moss growth.

Zinc Strips

Zinc 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 of Moss

Chemical 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. 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.

The decision on what method is the right method for roof cleaning in Seattle 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 roof cleaning in Seattle. We look forward to any comments or questions our readers might have and we welcome an open discussion on roof cleaning.

Roof Cleaning Seattle 425-501-3745

Leave a comment

Your Roof? would you rather replace it/or clean it? The answer should be one of monetary value. Cleaning your roof on average costs you about $350 dollars while replacing your roof costs between $11,000-$17,000 dollars, according to costhelper.com 

The amount of cleaning depends on your area, but really though King county is ripe for algae growth we are in the national danger zone for moss growth. Whether it direct sunlight or in shade. PWNG offers up to a 3 year warranty on roof cleaning. Not only is that unheard of in our area, but we are the only company locally that is a member to the RCIA, which sets a standard for roof cleaning. Always remember that when asking for a price quote from a contractor to ask them whether they will pressure wash your roof. Read some of our previous posts to find out why you should never pressure wash a roof.