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What Are Those Black Stains on My Roof

Black Streak Roof Algae Springfield Pa

What Are Those Black Stains on My Roof

The black stains or streaks on your roof are Gloeocapsa Magma Algae, which is often called “Roof Algae”. Roof Algae is most prevalent on a north facing and shaded roof slopes.

Gloeocapsa Magma Algae is a Cyanobacteria Bacteria that feeds on moisture and the limestone used in today’s shingles. Cyanobacteria Bacteria have a bluish tint but develop a dark outer UV protecting coating. It’s this protective coating that stains and streaks roofs.

Why Do I See More Roof Stains Now Than In The Past

Up until about thirty years ago; roofing shingles were manufactured with felt, asphalt and colored stone granules. After that period of time, shingles were made of a fiberglass mat, asphalt, limestone and colored stone granules. Limestone is cheaper than asphalt and was added to make the shingle heavier. The limestone provides food for the roof algae.

Can Black Stains Cause Damage to My Roof

There is very little evidence that roof algae causes damage to your roof but is very unsightly and reduces the curb appeal of your home.

Roof Algae Cleaning Methods

There are many companies that will offer different methods and products for roof cleaning but they are a temporary solution at best. At worst; your roof, gutters, siding and landscaping will be permanently damaged. Often the cleaning products contain bleach or phosphates. These methods and products are a short term solution and the roof algae will return.

Zinc or Copper Strips Installed At the Roof Ridge Will Help Prevent Roof Algae Growth

Over the years we’ve observed that roofs with zinc or copper strips installed on the roof ridges have very little algae growth. Zinc or copper strips won’t kill the algae but will help prevent further growth. With rainfall, the zinc strips leach out zinc carbonate and copper strips leach out cupric ions. These leached-out solutions have prevented further roof algae growth and black roof stains. Unfortunately there is not a permanent solution to clean black streaks from your roof.

With-in the Last Ten Years Roof Shingle Manufactures Have Made Shingles Algae Resistant

Most shingle manufactures today are formulating their shingles with copper-containing granules to be algae resistance for up to ten years. Commonly their warranty provides for a roof cleaning, not a roof replacement. Atlas Shingles are treated with a Scotch Guard Protector, which Atlas claims will provide more resistance to roof algae.

Contact us today if you have roof algae or any roof concerns and we’ll arrange for a free no-obligation inspection.

To see a complete line of our roofing material offerings, give us a call today at 800.798.2950.

At Excel Roofing, we strive to be the best roofing contractor that has built the trust of our entire community. Our reputation is our most important asset and we are proud to be one of the best roofing companies in Pennsylvania, New Jersey and Delaware.

Excel Roofing installs new roofs and performs roof repairs in the following areas:
Abington Pa 19001 Ambler Pa 19002 Ardmore Pa 19003 Aston 19014 Blue Bell Pa 19422 19424 Broomall Pa 19008 Bryn Mawr Pa 19010 Bala Cynwyd Pa 19004 Berwyn Pa 19312 Chadds Ford Pa 19317 Chestnut Hill Pa 19118 Chester Springs Pa 19425 Clifton Heights 19018 Collegeville Pa 19426 19473 Conshohocken Pa 19428 Doylestown Pa 18901 18902 18933 Drexel Hill Pa 19026 East Falls Pa 19129 Elkins Park Pa 19027 Garnet Valley 19061 Germantown Pa 19144 Gladwyne Pa 19035 Glen Mills Pa 19342 Glenmore Pa 19343 Glenside Pa 19038 Glen Riddle Pa 19037 Harleysville Pa 19438 Hatboro 19040 Haverford Pa 19041 Havertown 19083 Horsham 19044 Huntingdon Valley Pa 19006 Jamison 18929 Jenkintown Pa 19046 Lima Pa 19037 Kennett Square Pa 19046 Lafayette Hill 19444 Landenberg Pa 19350 Lansdowne Pa 19050 Limerick 19468 Lower Makefield Twp Pa 19067 Malvern Pa 19355 Media Pa 19037 19063 19064 19065 19086 19091 Merion Station Pa 19066 Morrisville Pa 19067 Narberth 19072 New Hope Pa 18938 Newtown Pa 18940 Newtown Square Pa 19073 Paoli Pa 19301 Penn Valley Pa 19072 Phoenixville Pa 19460 Kimberton Pa 19460 Plymouth Meeting 19462 Villanova Pa 19085 Radnor Pa 19008 19080 19087 19088 19089 Rosemont Pa 19010 Rose Valley Pa 19063 19086 St. David’s Pa 19087 Springfield Pa 19064 19118 Swarthmore Pa 19081 Thornton Pa 19373 Wayne Pa 19080 19087 19088 19089 Warrington 18976 Warminster 18974 Wawa Pa 19063 Wynnewood Pa 19096 Yardley Pa 19067 West Chester Pa 19380 19382 Haddonfield NJ 08033 Collingswood NJ 08108 Cherry Hill NJ 08003 Woodbury NJ 08097 Wenonah NJ 08090 Pitman NJ 08071 Riverton NJ 08077 Cinnaminson NJ 08077 Moorestown NJ 08057 Mt Laurel NJ 08054 Mt Holly NJ 08060 Greenville De 19807 Montchanin DE 19710 Westover Hills DE 19807 Wawaset Park De 19087 Bancroft Parkway DE 19807 Talleyville DE 19803 Arden DE 19810 Winterthur DE 19735 Hockessin De 19707 Yorklyn DE 19736 Ardentown De 19810

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Wednesday, 19 December 2018

Why Choose Excel Roofing and Siding

Our goal is to provide homeowners with a quality roof at an affordable roof cost.

Our promise is to assure that our customer’s rest easy knowing they have a top-quality roof system installed by the best roofing contractor.

We start every roofing project with a free inspection and evaluation to determine if the roof needs to be replaced or simply repaired.

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  • A Company That You Can Trust
    Excel Roofing and Siding replaced my roof and I was completely satisfied with their work. Kevin Creighton was very professional and made certain that everything was done on time and with-in the budget.
    Lou-Haddonfeild NJ
    January 13, 2012
  • Thanks Chuck, Great Job
    We had a roof leak and Chuck Keller was referred to us by a friend. I was incredibly impressed with his roofing knowledge and attention to detail.
    Molly-East Falls Pa
    April 18, 2012
  • Roof Leak Fixed
    We had a hard to find leak. Kevin Creighton did a water test, replaced some loose caulk and fixed the problem. He didn't even charge us.
    Jackie-Springfield Pa
    May 7, 2012
  • Excel Roofing and Siding restored our entire slate roof
    They replaced the valleys, copper dormers and copper gutters. The quality and price were unbelievable. Excel Roofing and Siding is the finest roofing company in the Philadelphia area
    Jacob-Elkins Park Pa
    October 22,2012