Moss. It’s the scourge of homeowners everywhere, ruining the overall aesthetic of your home as well as causing expensive damage if left to grow. Even a small concentration of moss can cause big problems, so it’s best to take care of it as soon as possible. However, there are steps you can take to keep moss from growing in the first place.
Roofing strips made of zinc or copper can be placed along the ridge of the roof or at different intervals down the roof. Copper has more coverage and is usually only installed at the top of the roof. Zinc strips may need to be applied at multiple intervals to be the most effective.
It’s preferable to have these strips added to the roofing system as the new roof is being put into place. But they can also be added to existing roofing for an extra level of protection for your roof. Both products have similar killing properties for moss and algae.
Zinc vs Copper Roof Strips Moss Prevention, Coverage
When water hits the zinc roofing strip, it releases zinc particles that then move down the roof with the water. These zinc particles do a good job of killing moss. When hit with water, copper strips release copper sulfate, which is a natural herbicide.
Installing copper strips will give you more coverage than zinc, which means you’ll kill more roof moss. Neither product provides a “long-term” solution: Installing zinc strips will give you around 5-8 years of protection while copper will give you a few more years.
The installation process for both is pretty similar, the only difference is that you may need to use more strips of zinc. This isn’t necessarily a difficult job, but as always when it comes to roof work, you could do more damage to the roof than the problem you’re trying to fix. Because strips are nailed into place, you are adding more holes to the roofing materials–not ideal.
You’ll want to read the recommended installation instructions for each product, but the process to install strips is pretty standard. For composite or asphalt shingles, you’ll first “break the seal” of a row of shingles, prying the bottom edge up so you can slide the strips under. After sliding the strips into place, you’ll nail strips into place.
For maximum protection, drive the roofing nails halfway and then add a bead of caulk or sealant. Once the nail is all the way down, add another bead of sealant over the nail head. This will help seal the hole as well as help the shingles to re-adhere to the rest of the roof.
Copper strips can cost three-to-six times as much as what you pay for zinc strips, so depending on the size of your home, this could be a factor. As with any roofing system component, though, price should not be the only consideration. You won’t need as much copper to finish the job and it lasts longer than zinc.
Beyond Zinc vs Copper Roof Strips: Other Ways to Prevent Moss
Moss likes a cool, damp environment and the Pacific Northwest provides plenty of both during the year. It also prefers the shade, so north-facing rooftops or homes with large leafy trees are usually the best breeding grounds for the spongy green stuff. If there are any imperfections in the roof, or places where water can gather, it’s a recipe for disaster.
So the best way to prevent the growth of moss is to make conditions as unpleasant as possible for moss. Along with water, moss thrives on debris found on most rooftops, including leaves, twigs, and other materials. This stuff can also trap water in the roof, so keeping your roof free of debris is a good first step.
Trimming or pruning trees with branches that overhang your home will go a long way to preventing an environment that promotes moss growth. Depending on the age or health of the tree, this might be a good idea anyway. If a tree is succumbing to disease, it won’t take much of a storm to drop a big branch right onto your home!
If that happens, reach out to Warner Roofing and Construction. Since 1992, we’ve been installing, replacing, and repairing roofs in Vancouver and the Clark County area. Give us a call if you have more questions about the zinc vs copper roof strips debate or if you have concerns about your roof and need a roof inspection.