Moss Helps Your Roof
The only thing that wears out your roofing is the radiation from the sun, it breaks down the oil in the roofing and after a set amount of time depending on the amount of oil in the shingle the material is unable to expand and contract with the temperature changes and starts to crack and become brittle. If you cover your roof with moss, the radiation will not be able to affect the oil in the material and the shingle will be able to expand and contract correctly.
Moss does not have roots it has hairs that wrap around the granules to hold on but does not grow under the shingles or into them. It only removes a few granules when you wash it off.
Zine strips are not worth it they are only effective for 7 years and 7 feet, the holes you put in your roof to attach it are a problem though
Effective Roof Cleaning
The only way to clean the roof is with a pressure washer, a broom, a wire brush, a screw driver and most chemicals all do more damage. Here is why. The moss is growing on a fungus – the same fungus that turns your driveway black. The same fungus that is impossible to stop from growing on your driveway, is impossible to stop it from growing on your roof.
So, to clean your roof you need to remove the fungus that the moss is growing on, chemicals don’t do it, nor a broom, or a screw driver, or a wire brush, or a pressure washer that is too small. My pressure washer, if I put the tip next to the shingle, I will cut the shingle in half; if I hold it back 4 feet the water will not touch the roof so somewhere in the middle is the perfect amount of pressure to remove the fungus that the moss is growing on. My pressure washer puts out 7 gallons of water a minute so my tip if my wand is 12 inches from the roof plus or minus 2 inches. Most homeowners use a pressure washer that is too small and their tip is 2 inches from the shingle plus or minus 1/2 inch and takes forever and has a huge risk of doing damage.
Be careful with chemicals – most break down the oil in the shingle and cause a lot of granules to fall off and if you don’t remove the fungus even though you managed to kill it, the moss will still be able to grow on it. Also, if you remove the fungus from the shingles there is no reason to put a moss treatment on the shingle because there is nothing to kill and the rain will wash most treatments off the roof, so save your money and clean your roof every 3-5 years.
Vents Cause Mold
The way vents work is when the air in your attic warms up it escapes out the vents at the top of the roof and draws in air through the bottom of the roof, this creates moving air like a hair dryer and if you keep things dry than the bugs will not feast on your structure. But we live in the Puget Sound and have a lot of moisture in the air 6 months of the year which we are not sucking the wet air into our attic and in the attic, it is a little warmer causing the air to rise and it gets the plywood on the underside of the roof all wet. Now you have your attic space which is cold, wet and dark creating a perfect environment for mold. After looking at 20,000 attics what I have seen is the more vents the more mold you will have.
What I recommend is to plug all your vent and create a dead air space, we know that dead are spaces are good insulators like your windows have this will also cause your heat bill to go down and now your attic is warm and dry mold and bugs will not like that.
This is not what the code asks us to do but the code is the same for AZ as it is here but we have different weather here and I believe we should have a different code. I have tried this idea on 500 homes and no issues yet.