Metal Roofing Accessories: Big Results From “The Small Stuff” George Allaster, Jr., Eastern Regional Sales Director, Marco Industries In metal roofing, sometimes it’s easy to overlook the “little things” that go into a successful roofing system. I say “system” because for a metal roof to perform and protect properly, many different things must work together. For example, if a fastener fails, it doesn’t matter how great the rest of the metal roof is during a driving Florida rain. That’s why it pays to not overlook “the small stuff.”
Ventilation is Vital
Ventilation is one of the most important aspects of a roofing system that is often taken for granted. In fact, proper ventilation is crucial to the performance and longevity of a metal roof. By keeping out moisture, dust and pests, ventilation protects the roof itself from damage. Most people have heard horror stories of mold and other moisture damage, as well as sky-high energy costs, all due to improper ventilation. As a result, ventilation itself is accepted as necessary. But while most everyone knows it is needed, not everyone realizes that there is varying quality and performance among the different types of roof ventilation. Here in Florida, deciding which type of roofing ventilation you should install with your metal roof is simple. Rather than relying on box vents, end gable vents, wind turbines (also called whirlybirds) or power ventilators, follow the U.S. Department of Housing recommendation. It states that continuous ridge ventilation is the most effective. It is the least dependent upon wind direction and it delivers three to five times more air flow than any other combination of ventilation. According to a Georgia Tech publication on energy-efficient homes, a combination of ridge ventilation along with soffit vents
Marco’s patented LP2 ridge vent features a 40-year limited warranty and Miami-Dade Country Approved Python modified polyester for superior net-free ventilation that reduces condensation and helps lower utility costs. 42
FLORIDA ROOFING | January 2020
is the best, providing even air circulation under any wind conditions. The Tennessee Valley Authority agrees, adding that turbine roof vents are the least effective and that power vents may use as much energy as they save. The choice is clear: a continuous ridge vent (in combination with soffit vents) will provide the best performance. But are all ridge vents the same? Absolutely not. There are three main variables to consider. Material is the first thing to look at when choosing a ventilation system. Some products on the market are made of polyurethane. This material constantly expands as it soaks up water and contracts as it dries out. This constant flux causes these products to crack and lose their ability to perform effectively. Have you ever seen black streaks on older metal roofs? That is the polyurethane ventilation disintegrating and literally running down the roof. Another popular material of venting manufacturers is polyester. Much better than polyurethane, polyester prevents moisture absorption and holds together to keep out pests. This is a solid choice, but not the best. The ideal choice is a combination of specially formulated polyester—manufactured from recycled material—along with polyethylene. Polyethylene is the strongest resin available on the market and provides the most durable performance. It is flame-resistant, clog-resistant and tear-resistant. And a very important fact for the harsh Florida sun, polyethylene is UV and temperature stable. Other materials are not. The second thing to consider when choosing a quality ridge ventilation solution is the warranty. Look for a written warranty that is clear in what it covers. Some homeowners and contractors have been caught shorthanded by not having a written warranty on a ventilation product they thought was warrantied. The most reliable products will be backed by a 40-year warranty. Be sure to ask what the warranty covers and if it is pro-rated (which will lessen your coverage over time). Lastly, make sure the product you choose has
2020 Florida Buyers Guide, Welcoming the New Year...and ASCE 7-16, Roofing Apprenticeship Program Continues to Expand, Attic Ventilation, Me...