The waterproof flexible flashing of Roof Tech’s AlphaSeal

Every homeowner recognizes the value of having a roof over their head, and how vital it is to have leak-free roofing that retains its integrity over time. When installers of PV systems are required to drill holes into rafters, it can damage shingles and allow rain and snow to permeate the roof and cause leaks. Roof Tech solves this challenge with AlphaSeal® system, the gold standard in flexible flashing.

The evolution of a revolutionary mounting system | In 1995, Roof Tech’s parent company Yanegiken, created the world’s first-ever leakproof mounting system to feature proprietary butyl tape, a synthetic, rubber-based material that provides a protective barrier against moisture. When Roof Tech was established in 2013 as Yanegiken’s U.S. subsidiary, they began to market RT-Butyl, which is impermeable to moisture and resistant to mildew, acids, alkalis, salts and aging from UV light.

Since then, Yanegiken and Roof Tech have completed more than 1 million rooftop installations all over Japan and North America – without a single leak. In 2021, Roof Tech took a quantum leap by registering AlphaSeal®, a proprietary system combining RT-Butyl with proprietary, stainless steel wood screws to create the first fully integrated mounting system that is 100% caulk-free.

Roof Tech mount

Roof Tech simplifies PV installations with 100% caulk-free mounting | Before 2021, installers who used Roof Tech mounting systems were required to place a bead of caulking around the base of each mount to provide added UV protection. But after conducting rigorous tests using static water pressure and accelerated aging, Roof Tech confirmed that the proprietary design of AlphaSeal made caulking unnecessary. As a result, PV installers now save time on the roof and can provide their customers with the confidence of watertight performance.

Now every Roof Tech mounting system features AlphaSeal® | Roof Tech has field-tested its proprietary AlphaSeal system for more than 25 years. Today, Roof Tech offers three mounting systems, all featuring AlphaSeal:

  • RT-CONDUIT MOUNT, Roof Tech’s newest product, is made for ½” to 1” conduit and can be used with a single-hole strap or conduit hanger for rafter or deck installation. Each RT-CONDUIT MOUNT comes complete with screw, mount, and flashing, seen below:
roof tech conduit mount
  • RT-MINI II is used to attach conventional railed mounting systems to any sloped roof comprised of metal, EPDM, TPO, or asphalt.
  • RT-APEX is the self-flashing, rail-less mounting system engineered to withstand wind speeds up to 180 mph.

Thanks to continual innovation and flawless performance, Roof Tech provides a 25-year warranty that includes its flexible flashing on all its products from the date of installation.

To learn more about Roof Tech products, visit

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