Dealing with Moss & Algae
In Anchorage, Girdwood and the Valley, we are always excited about Southern exposure. The sunlight for Alaskans is so important. It is also important for your roof. Moss growing on any roof surface will be more severe on roof sections that are shaded and exposed to periodically damp cool weather conditions. Unfortunately cool, damp and shaded describes most of our roof area. Over the years of roofing in Alaska, we have discovered ways to best explain the moss problem to home owners, treat and prevent the moss problems. Please read the information below.
What to Expect: How Holland Roofing provides roof top moss service.
It will be impossible to clean a very old worn out roof without damaging it. Replacing a much older worn roof is the only recommendation Holland Roofing will give if the roof material is in very poor conditions. In most cases, Holland Roofing will not even offer moss treatment services to roofs older than 15 years old. If the roof shingles are fragile, brittle, cracking, curled, the risk of damage to the roof during moss removal is much more likely. The roof may look cleaner, but its remaining life may be reduced by aggressive cleaning. Holland Roofing cannot guarantee that roof cleaning will not cause more damage or increase the life of the existing roof.
Raking & brushing roof moss:It is possible to remove most of the moss from a roof surface by gentle cleaning using a soft brush, broom and a garden hose. Brushing or raking is done with care to minimize damage to the shingles themselves.
Holland Roofing uses a flexible leaf rake or brush to remove moss, most but not all the debris on the roof after raking will be swept off the roof edge. Sometimes a low pressure spray with a garden hose will be used to aid in clearing off the loosened moss.
Power washing an asphalt shingle roof (or a wood shingle roof in old, worn, fragile condition) is a process that can damage the roof by breaking shingles or by loosening the protective mineral granules from the shingle surface. We do not recommend power-washing asphalt shingles or any other roofing product that can be damaged by high pressure spraying. Holland Roofing will not power wash the roof.
Moss Kill Treatments:Treatment that “kill” the moss or lichens work similar to weed kill for the yard. It may require more than one treatment and may need to be done every other summer. This will help lessen the growth of what is existing and help prevent new growth. Please understand that the roof will not appear new or clean after a moss service. The large thick areas of moss growth will be reduced but some moss will remain in the key ways (small cracks or area between the shingles). It takes time, sunlight and rains for the moss kill solution and zinc to fully affect the moss still remaining. In most cases moss service does improve the look and life span of the roof.
Zinc Strips: Holland Roofing can provide and install zinc strips along the ridge of an existing roof that will help to slowly kill off moss or lichens as rainwater washes over the metal and down the roof surface. This method is suitable for both prevention of future or further moss or lichens growth on the roof and for gently treating an otherwise fragile old roof. Zinc looks like a roll of 3 inch wide metallic ribbon. It is unrolled and fastened at the high points in the roof. It is usually installed alongside the ridge vents and peaks.
Give the roof surface more sunlight:Trim back trees whose branches overshadow the roof surface. Keep the roof clean of organic debris like leaves or pine needles which may collect in valleys or at other roof locations. Holland Roofing may cut back small branches that are actually hanging over the roof surface but we will not remove entire trees or large branches. A tree service company should be contracted to do this type of work
Algae-resistant shingles:Chemically treated roof shingles are available from several asphalt roofing manufacturers who offer these products which are resistant to moss, lichens, or algae growth on roofs. New asphalt roof shingles are available with an inclusion of chemicals that resist moss, lichens, algae, and even fungal growth. Resist does not mean moss-proof or lichens proof however it does make a big difference. Discuss this option with us when it’s time to replace the roof. Please call us with any additional questions.