Proper roof design is critical to avoid roof leaks when it comes to the installation of flashings and penetrations.
Flashings and penetrations are particularly critical on low-slope, standing-seam metal-roof systems because the metal serves primarily as a watershed. The water-shedding capacity is functionally similar to roof shingles - it relies on a steep slope to rapidly release the water. In contrast to waterproof roofs, which are intended to function under occasional standing water, metal roofs are not designed to be completely leak-free under long-term water immersion. Therefore, waterproofing must be provided at critical junctures, such as flashings and penetrations.