A new 5V metal roof requires thousands of screw attachments through the metal.

Solar Pool Heaters | Roof Penetrations | The Truth

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The truth is that regardless of the brand of solar pool heater you choose, to secure them to your Florida roof properly a solar installer must use screws to achieve resistance against wind uplift. This strikes fear in some people, but the risk of roof leaks is extremely minimal. Dealers (and the industry as a whole) would not survive for decades if the product and workmanship resulted in frequent occurrences of roofing problems. The industry as a whole has been very successful in developing products and techniques that prevent roof leaks.

A new 5V metal roof requires thousands of screw attachments through the metal.

A new 5V metal roof requires thousands of screw attachments through the metal.

Some roofs, like metal 5V crimp roofs, have literally thousands of screws with EPDM washers securing the metal roof pans to the sheathing. Virtually all roofs have plumbing vents, and most have some form of ventilation system, all which require large roof penetrations. We accept these necessary through-roof holes, so sealed attachments for solar panels should be no big deal if done correctly. That’s not to be taken lightly, because doing it incorrectly can and does result in problems occasionally. Hiring an experienced licensed certified solar contractor is your best defense against shoddy workmanship. You should also check your contractor’s insurance certificate. Insist on a permit where required, which adds not only an inspection by a building inspector, but further assurance that the contractor is licensed and insured as required by law.

The only type of roof that does not require some kind of penetration is a standing seam metal, on which you can attach solar panels with non-penetrating hardware that clamps onto the seams. This method is relatively expensive for a solar pool heater and requires an aluminum substructure. It is rarely used (although for more expensive solar electric panels, this method is commonplace).

There is a misconception (and often a lie) that solar pool heating panels with separated tubes required fewer or no roof penetrations. The truth is that these types of panel often require more roof penetrations. For example, a typical fully body panel system that we sell with nine 12′ solar panels requires approximately 54 fasteners including the body straps. One of our separated tube panel competitors uses alligator clamps with no body straps. On their system each panel requires four clamps secured by two fasteners each. That is a total of 72 fasteners on an eight panel system. The picture below shows this competitor’s product. I took this picture two days ago, and I counted exactly 72 fasteners on the nine panel system — 33% more than our full body panel.

Heliocol Panels Require More Roof Penetrations Than FAFCO Brand Solar Pool Heating Panels

Heliocol Panels Require just as many Roof Penetrations as other Solar Pool Heating Panels because of top an bottom clamps with multiple fasteners per clamp.

The figures above do not include additional fasteners required to attach plumbing. Since our systems allow same-side feed and return plumbing, our plumbing runs are typically much shorter, requiring fewer fasteners.

The total number of fasteners required depends on an engineering calculation considering the location of your home and proximity to open spaces, especially large bodies of water. Ultimately we are splitting hairs between panel brands — whether it’s 54, or 72 fasteners, the bottom line is that you will have quote a few attachment points regardless of brand, and there is little to worry about. We’ve done this… thousands of times.

Selecting a proper sealant is also important. The good stuff costs a bit more, but it’s well worth it. A tri-polymer sealant that will not shrink and crack over time is the best practice. Some popular sealants are not compatible with asphaltic surfaces (as in asphalt shingles or rolled roofing material), so it’s important to make sure the sealant used will adhere to the surface and provide a long-term waterproof seal. I like a product called Geocel 2300, but there are several quality products on the market, some of which are marketed specifically for solar roof attachments. Common silicone or urethane caulk won’t work, so make sure your dealer knows what they are doing.

If you are concerned about roof penetrations, hopefully my final point will help. In Southwest Florida we are required to meet the 2010 Florida Building Code which requires use of ASCE 7-10 for wind load calculations. The design wind speed for most of our area is 160 mph, going up to 172 mph in Marco Island. The codes are quite stringent, and if we experience winds in excess of these, catastrophic property loss will be you main concern, not your solar pool heating panels. With the exception of catastrophic wind events, solar panels are designed to stay on your roof firmly without any roof penetration problems. We can’t control mother nature, but we can install your panels to meet all instructions and codes!

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