According to the National Roofing Contractors Association, metal roofing materials have seen a healthy increase in popularity in recent years. They’re well liked for their fire-resistance and durability. But if you’re also wanting to mount solar panels on them, metal roofs present unique challenges in installation process.
If you are looking to have solar panels installed on your home, there are a few things you need to consider that are unique to metal roofing. The following tips are adapted from the advice of Cliff Schrock, senior engineer here at SunModo:
Don’t bend roofing seam to fit a clamp. Doing so will void a roof’s warranty. Manufacturers make a wide variety of clamps for all metal roof types. Find a clamp that fits correctly.
Find solutions for reverse seam decks. According Schrock, reverse seam decks are the most difficult type of roof form to deal with.
What often happens is the valley area is too narrow for mounts and doing so would disrupt water flow. At the higher end of the roof, a special mount with spacers is necessary in order to avoid crushing the deck during tightening.
Configure the rails east-west when seams run north-south. Doing so provide maximum system strength on a standing seam roof, particularly in north and south. The rails provide strength in the east and west.
Consider what’s below the mounting system… since it’s only as strong as the roof beneath it. Some metal roofs have foam insulation directly under the deck. Tightening mounts could crush the insulation. In this case, you may need a system that includes a spacer. Roll insulation under many metal roofs is already crushed at the cross beams, and further fastening is an not issue.
Use the right self-drilling screws. Use types that are made for self-drilling through a metal roof into wood. These screws typically have a gasket on them for waterproofing. There are special self-drilling screws for going into heavier metals, as well.
Get help from a structural engineer or the roofing manufacturer to help you find the right screw length to drill through the roof either into wood or into metal underneath. This is extremely important so you don’t void the roof warranty and also get the correct attachment strength.
If you’re considering installing solar panels on your roof, it’s important to consider the life expectancy of your current roof. If you have panels installed, but need a new roof in a few years, it’s a significant expense that you want to avoid.
If you plan to replace your current roof, a metal roof is favorable for multiple reasons.
One of the benefits of a metal roof is they are the longest-lasting option you will find. So, you won’t have to worry about the roof being replaced after you install solar panels. Plus, solar panels can be installed without the risk of water leaks, such as when holes need to be punched through an asphalt shingles roof.
While metal shingles require a bit more research, learning how to install on this high-end roofing system can boost your bottom line and bring solar to homeowners that often struggle to find a willing and able solar installer.