How does DL-40 Plus stay watertight?
The four-way interlock, along with careful flashing during the installation process, makes leakage impossible. The locked-down edges of the shingles cannot be lifted, unlike the unsealed edges of other roofing products. An independent lab in Dade County , Florida tested DL-40 Plus with 110 mile per hour wind-driven rain without a single leak. Also, DL-40 Plus roofs successfully weathered hurricanes Gilbert, Hugo, and Andrew. DL-40 Plus indeed provides total home protection against the elements.
