What Pitch Can Standing Seam Metal Roofing Be Used On?

Construction

• A standing metal roof is made of panels of sheet metal laid vertically on the the roof surface. A panel is riveted to cleats on the roof and the edge of the next panel is crimped over the cleat, forming a watertight, standing seam. If a metal panel needs to overlap a lower panel, it's soldered to keep wind-blown water from penetrating the seam.

Pitch

• A standing seam roof may be used with almost any pitch. The shallowest pitch that can accommodate the system is an almost flat 1/4:12. That's 1/4-inch of vertical drop for every 12 inches of horizontal distance. As with any roofing system, the steeper the pitch, the better it will shed water.

Shallow Pitch

• Metal panels on shallow-pitched roofs -- less than 3:12 -- need to be machine crimped to ensure a tight seal. If every panel covers the full vertical length of the roof, there are no seams that water can penetrate nor are there raised solder joints that can cause pooling on a shallow roof.

Tips

• Installing standing seam roofing is a traditional craft. Find a reputable roofing contractor who is experienced in installing the system. Copper and stainless steel are the most durable materials, but are also the most expensive. Painted steel -- often called tern
  -- can last for many decades if it's kept painted and rust-free. Walking on a metal roof can puncture it and flatten the seams, reducing their effectiveness in keeping water out.