What is a standing seam metal roof?
How it is built
- Panels. Usually 12 to 18 inches wide and cut to run in one piece from eave to ridge.
- Seams. Raised legs on each panel edge interlock. Snap-lock panels click together; mechanically seamed panels are crimped closed with a seaming tool for higher wind ratings and lower slopes.
- Clips. Fasteners go through clips hidden under the seam, letting the panel slide as it heats and cools. A Georgia roof swings a long way in temperature between a July afternoon and a January night, so that movement matters.
- Trim. Ridge, eave, rake, valley and wall flashings are bent to fit.
Standing seam vs exposed fastener panels
Exposed fastener panels, the ribbed sheets common on barns, are screwed through the face with rubber washers that age in the sun and eventually need attention. Standing seam has no exposed screws in the field and generally lasts longer, commonly 40 to 70 years with a quality paint finish, while exposed fastener roofs often run 25 to 40 years with screw maintenance. Standing seam also costs considerably more because the panels, trim and labor are more involved.
Things to know before choosing it
It goes over a solid deck with a high temperature underlayment. Hail can dent it, and many policies limit coverage for purely cosmetic dents on metal, so read your policy first. Some Georgia HOAs require approval for metal. See metal roofing in Georgia and HOA roof approval in Georgia.