While black stains on roofs are a cosmetic issue, moss growth is more than just cosmetic. Not only does moss look terrible on roofs, it will also shorten the life of the roof covering and possibly lead to roof leaks. Whether you have wood or asphalt shingles, moss can grow on the roof if it doesn't dry properly.
Zinc Strips kill moss. The moss dies and the roof stays moss free for 10 feet under a zinc strip for five years or so if it stays in place and stays flat. Homeowners can install strips of zinc, purchased at a hardware store.
For decades, zinc strips have been used to keep moss from growing on roofs. This is an explanation of how they work and how they are installed. It also explains the limitations of zinc strip, from the point of view of good roofing practices and experience.
Fitting copper to your roof is the best way to prevent roof moss. The copper prevents moss growth permanently and will keep your roof clean and moss free. We fit copper to roofs in and around greater Belfast. When the copper is fitted to your roof it combines with the rainfall causing a chemical reaction.
An asphalt shingle roof will last for many decades if you install copper roof strips up on the ridge and down any hips. Tim Carter was the first person in the world to discover that copper ions washing off a copper strip prevent asphalt from oxidizing. Oxygen that bonds to asphalt up on your roof causes the asphalt molecules to cross link.
Install Copper Strip on Roof You can install a inch-wide thin copper strip on a new roof so an inch of the copper strip rests under the cap shingles and the copper folds under the last full shingle on the roof. Copyright Tim Carter. Watch this short video first.
Here are the recommended roof installation procedures for Zinc Strips. Then we will explain our experience with copper, zinc strips — Installation issues. Install the strips every 2 to 3 feet down the roof and across it.
In this video, This Old House general contractor Tom Silva shares tips for keeping a roof free of moss and mold. You can cut strips of zinc flashing copper and lead work, too and slide them under a course of roof shingles to kill lichen and moss growing there, or you could just buy these premade strips from Shingle Shield. The premade ones are much quicker and probably neater looking. It's not a bad idea to suggest to customers that overhanging tree branches are what's keeping their roof moist in the first place and allowing the vegetation to grow.
Roof cleaning measures such as pressure washing can remove or roughen the surface of the roofing material, reducing the intended productive life of the roof. At best it is a messy, temporary solution which would need to be repeated frequently. This sort of procedure also does nothing to kill the spores that created the Algae and Black Mold.
Q Our properties in this area suffer from heavy moss on the roof, leading to frequent gutter overflow. A roofing contractor has suggested that he can brush the roof clear of moss, working from roof ladders, and then install copper strips at intervals on the roof. Supposedly this will react with rain to deter moss growth. I wonder if you have heard of this treatment and its efficiency.