Photo: Courtesy of Aluminum Shake Roofing

Q: I have a damaged or faulty roof. How can I tell when to repair or to replace?

A: It depends. Marc Silva of Macsteel Hawaii advises consulting an expert first. “Get a contractor to come out and give you a price for both. Then, figure out how long the repair would last versus how long a brand-new roof would last. Do a life-cycle cost analysis based on the two,” Silva says. Remember, a good contractor will also be able to tell you which roofing problems can be fixed with repair and which cannot, so don’t try to make the decision on your own.

Q: We are starting to see signs of leakage on our ceiling. What could this be and how can we fix it?

A: The leakage could be due to faulty flashing. Flashing is material that is applied at roofing intersections and terminations, such as valleys, eaves, ridges and skylights. It is configured to resist water. It’s also “where you’re primarily going to see any leakage,” Silva says. “The only place the panels are going to leak are at the flashing or at improperly installed [roofing] panels.” If your flashing is leaking, you may need to replace, rather than repair it.

Q: How long should my flashing last?

A: “Flashing is generally where all the money in a roof product is,” says Fred Rehm of Aluminum Shake Roofing. That said, it should last as long as the roof will last. The flashing is what will protect your roof from leaking, so make sure it is done properly. “It should be better than the roof,” says Rehm. “The guy who does that right is probably going to do the roof right, too.”
   At the same time, if the flashing needs replacing, it’s a good bet your roofing will need replacing as well. To protect your roof and your investment, make sure your flashing is covered by the roof warranty. Many roofing manufacturers will only cover the flashing if it is made with their products. That’s because flashing is often manufactured to work with specific companion roofing materials.

Q: I’ve heard that not all homes can be outfitted for PV because roof shapes are sometimes incompatible. What can I do to make my roof work?

A: “Everybody can have some PV,” says Mike Benes of Hawaiian Island Solar. But the installation is easier if the roof’s surface area is larger. Traditional PV works with a central inverter. This inverter works by combining all the panels’ energy to create electricity. Essentially, the central inverter treats all panels as if they were one big panel. Because of this, “All the panels connected to the same inverter should be facing the same direction,” says Bruce Okimoto of Hawaii Home Expo. “You wouldn’t be able to use the same inverter for panels that are on two sides of the roof.”
   But what if you don’t have a large plane on your roof for multiple panels? Ask about a micro inverter. Micro inverters work with separate converters on each panel. Thus, “If people have panels going in different directions, it doesn’t matter. In either case, it’s possible to install PV,” Benes says.   

Q: I’m planning on outfitting my home with PV. What should I do to get my new roof ready?

A: “If you’re building a new roof from scratch, then the more south-facing the roof, the better,” says Benes. “The panels lose a little bit of efficiency facing too far east or too far west.” Because PV panels must be screwed into the rafters of your home, penetrating the roof panels, you should also talk to your roofer about any prep work they may want the PV company to do. “Some roofers prefer we wrap our screws and integrate them into the roof,” Benes says. Wrapping the screws helps to ensure that water does not leak through the penetrations.

Q: I’ve had my roof for years but want to install PV now. Does that mean I need a new roof?

A: This depends on exactly how long you’ve had your roof and how much longer you expect it to last. “It has to last as long as those panels are going to last,” Rehm says, “at least 25 years, maybe even longer. You need a roof that doesn’t need much maintenance and is going to last a long time. You need one that can be walked on.” Silva adds, “To protect the investment of PV systems, you’ve got to make sure you have a high-quality roof and one that can resist the winds. You might as well get one that can stand the test of time.” For a proper assessment, call an expert. Many roofers will do free consultations.

Q: Are there any special weather-proofing considerations for Hawaii’s climate?

A: “Periodically, we have hurricanes, so it’s not a bad idea to flash or trim your roof to withstand high winds,” Silva says. You might also want to consider investing in a tie-down system, which will help further secure your roof. Additionally, make sure your roofing material can withstand Hawaii’s weather. “We have salt-laden air and when it rains, it can drip under the eaves and go back up under the panel,” says Silva. “So [Macsteel Hawaii] puts a thicker barrier coating on the roof to prevent corrosion from the bottom as well.” In Hawaii’s hot sun, the roofing material should keep your home cooler, if possible. “The Country Manor Shake [available at Aluminum Shake Roofing] is the coolest roof you can buy,” Rehm says. Installing a foam insert between the roof and roof deck (the layer of roofing material above the rafters on which the other roofing material is attached) keeps the home cooler, too. You also need to consider weather when it comes to your PV panels. Make sure your panels are hurricane-rated to withstand high winds.

Q: Does my old roof need to come off to install my new roof? 

A: It’s possible to install new roofing material over old, if it’s light enough. However, Rehm generally likes to tear the existing roof off to ensure the condition of the deck below is in good condition. “It’s probably a good idea to take the old one down,” Silva says. “With shingle, they’ll put three or four layers down. As a metal roofing manufacturer, we want to get straight down to your framework. The better you make your foundation, the better your roof is going to be.”