Causes: Algae growth causes a dark discoloration on roofs. The algae is usually brown to black in color which results in a streaked, dirty looking rooftop. It can be mistaken for soot, dirt or tree droppings, which typically produce only localized discoloration. It's caused by the growth of air-borne algae which deposits on your roof. The good news is that algae growth does not affect the service life of your roofing material. It occurs most often in warm, humid climates such as the Southeast (where algae-resistant shingles are available).

Recommendations: Discoloration of roofs caused by fungus or algae is difficult to remove, but may be lightened by spraying a diluted solution of chlorine bleach, trisodium phosphate, and water onto the roof. Solutions range from one cup TSP, one gallon bleach and four gallons of water, to one cup TSP and 2.5 gallons each of bleach and water. This solution can then be rinsed from the roof in 10 to 15 minutes. Do not scrub. Scrubbing will loosen and remove granules. After spraying be sure to thoroughly flush the roof and the greenery around the home (grass, bushes and shrubs) with water. The effectiveness of this type of cleaning may only be temporary, and the discoloration may recur. High pressure washing is not recommended due to the possibility of removing granules, thereby shortening the life of the Roofing System.

Causes:

• Improper installation on a new roof.
• Drying and cracking on an old roof.
• Dented by improper nailing.
• Settling of the structure.

Recommendations: In most cases it is only necessary to remove and replace the flashing and shingles around the damaged area.

Causes:

• Improperly applied felt.
• Wrinkled underlayment.
• Roof deck movement.
• Spacers not used in between roof deck boards.
• Poor roof ventilation.
• New shingles applied over old, rough shingles.

Recommendations:

• Allow moisture to escape the Roofing System. This can be a slow process and could take until the following spring. Once the Roofing System reaches the proper moisture content, the roof should lay flat and the buckling problem should not return.
• Remove the shingles that are affected. Cut the wrinkle in the felt and replace the shingles.
• Add ventilation to the attic space. The minimum requirement is one square foot of net free vent area per 150 square feet of attic floor space if a vapor retarder is not present. If a vapor retarder is present, the amount of required ventilation can be reduced to one square foot of net free vent area per 300 square feet of attic floor space.
• Add ventilation to the attic space. The minimum requirement is one square foot of net free vent area per 150 square feet of attic floor space if a vapor retarder is not present. If a vapor retarder is present, the amount of required ventilation can be reduced to one square foot of net free vent area per 300 square feet of attic floor space.

Causes:

• High nails
• Lack of back coating
• Under-saturation of asphalt felt in organic shingles.
• Lack of ventilation
• Improper number of fasteners

Recommendations:

• Check location and number of fasteners
• Added roof ventilation can often help correct this issue

Causes: Moisture in the shingle

Recommendations: If the blisters break open revealing the asphalt, the affected shingles should be replaced. You should then consult with the manufacturer of the shingles.

Causes:

• Improper fastening
• Exposure to high winds

Recommendations: Replace shingles that have completely blown off. For shingles with tabs blowing up and down, hand seal the shingles with asphalt plastic cement, commonly referred to as flashing cement. This roofing cement must comply with ASTM D4586 - Type I or Type II, which is the standard specifically for asbestos-free asphalt plastic roof cement.

Causes: Spots are caused by leaks in the roof.

Recommendations:

• Check attic for leaks in deck.
• Check chimney, walls, boots and vents for cracks in flashing.
• Check rafters for leaks that "travel" away from original source.
• Check eaves for water backing up from ice dams.
• Check roof for damaged shingles.

Causes: Normally a certain number of granules will be loose, especially after application. These granules are called "riders" and are a normal result of the manufacturing process. Granule loss does not affect the service life of the shingles unless granules can be seen missing on the surface of the shingles, thus exposing the asphalt or Fiberglas mat.

Recommendations: On aging shingles, missing granules indicate a need for replacement.

Causes: Rotting is caused by absorption of moisture by the mat at the core of the shingle. This is a common problem with organic-based shingles.





Roof Danger Signals Brochure - View



Addressing The "Growing" Problems On Roofs Caused By Algae, Lichen, Fungus, and Moss.

Fact:	Algae, or Gloeocapsa Magma, can spread... from one infested roof to another via the release of airborne spores. As more homes are built closer together, this hardy algae has been able to spread rapidly.
Fact:	Algae is well adapted to extreme conditions... heat, long dry spells, UV rays, heavy rain, intense cold, thick snow or high winds doesn't deter it.
Fact:	The dark color of Algae is a pigmented protective sheath... that encapsulates each cell to protect it from UV rays
Fact:	Copper and Zinc can both inhibit algae growth... Zinc (including pellets) however does have other inherent problems, such as: it's limited ability to be color matched to roofing shingles, attachment method to roofing shingles, cost and the occasional "bloom" effect due to the build-up of zinc oxide. Copper granules are used instead of zinc for these reasons.
Fact:	Copper is 10 times more effective against algae than Zinc... Zinc actually becomes less effective against algae quicker than copper
Fact:	AR shingles at work…some granules covering the shingle contain Copper encapsulated by a specially developed coating allowing Copper (cupric ions) to be time-released to prevent algae over a long period
Fact:	Dew is the dominant source of water for algae and is the "agent" best suited for the release of the copper in Algae Resistant shingles. Rainwater, although effective, runs off a roof too quickly to provide significant leaching of copper. Dew is also present more days than rain.
Fact:	Algae can go for long periods of time without water... It is unaffected by heat or downpours and is dormant in winter. Algae secretes a material that adheres them firmly to the shingle surface.
Myth:	Algae is killed immediately by copper. FACT: Algae cells are poisoned over time.
Myth:	Algae is a fungus. FACT: Algae, or Gloeocapsa Magma belongs to the Cyanobacteria branch in the Eubacteria family and is not a fungus.
Myth:	Installing a copper ridge or hip shingle with copper granules on an existing roof may overcome an existing colony of algae. FACT: AR granules have not been proven to kill existing algae.
Myth:	Are "FR" or Fungus Resistant shingles better? FACT: "FR" is an inaccurate name since fungus is not the actual source of the suggested problem. Additionally, copper granules have not been proven to inhibit fungus growth.

What Does it Look Like?	Dark/black or green stains or streaks on roof... Also called "Blue-Green Algae" (Cyanobacteria) and "Gloeocapsa Magma"	Green, connecting colonies… Includes mold & mildew	Green, spongy clumps… can be random growths.	Orange, White or Yellowish spots… in a star burst shape
What's Needed for Growth?	Moisture, inorganic food sources (asphalt fillers), airborne spores, proper temperature	Moisture, organic food sources (soil), spores, proper temperature - 40 F to 100F.
Where Does it Grow?	Nationwide; 80% +/-. Mostly SE, coastal, Pacific NW. High humidity.	High humidity, heavy shade, any exposure. Heavy and/or low tree coverage aids growth.
Typical Roof Exposure?	Mainly North facing, but can occur on all exposures.	Any exposure. Heavy and/or low tree coverage aids growth.
Impact on Roof?	Aesthetics Only	Aesthetics, poor drainage, slippery, potential to lift shingles, possible premature deterioration.
Are Algae Resistant Shingles Effective?	Yes…	No, may inhibit growth in early stages only, will not prevent growth.
How Do You Get Rid Of It?	Wash the Roof Shingles with "Anti-Algae Solution"*. Apply at low pressure, wait 15 min. rinse with low pressure water. Protect plants/shrubs. Do not power wash. Use Fall Protection.	Remove initial bulk of growth with stiff brush or broom. Then treat the roof as you would for algae.
*Anti-Algae Solution: 4 Gallons of water, 1 Gallon of bleach, 1 Cup of Tri Sodium Phosphate (TSP)

4 Types: 1. Algae 2. Lichen 3. Fungus 4. Moss

ALGAE GROWTH
	Extensive Algae growth - in both green and black. Different colors are evident. Dark appearance is a protective layer the algae have developed to protect itself from damaging UV rays.
ALGAE, LICHEN, FUNGUS
	Evident are Lichen, Fungus & algae. Notice the vent metal has inhibited growth. This observation is what initially prompted researchers into finding metals that prevent algae growth to take place. Exposure: Note the algae-free surface on dormer roof.
ALGAE GROWTH
	Extensive algae growth. The area below the window is free of algae due metal flashing... run-off of the metal inhibits growth Algae predominantly grows from the bottom - up, due in part to the amount of time water is on the roof.
LICHEN & FUNGUS GROWTH
	Fungus - predominantly at the shingle edges and key ways. Left to grow may eventually damage the shingles by lifting them and further inhibiting water run-off.
	MOSS • Moss due partly to low slope, shady location, organic material & exposure. • Water is retained on the roof; thus essentially aiding the growth. • Organic material needs to be present for growth or moss cannot take root.
	White: Very Low Algae, Moss, Lichen and Fungus Growth Yellow: Low Alga, Moss, Lichen and Fungus Growth Red: Severe Algae, Moss, Lichen and Fungus Growth

What You Should Know About Shingle Roofs - View

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