When wind blows snow from one roof area to another, snow drifts form on the lower roof in the wind shadow of the higher roof, creating an unbalanced load.  Snow melt ponding adds to the load and may also cause water damage and leaks at the intersection.

Sloped Retrofit Metal Roofing Solution For Lower Roof

Abrasive roofing materials [asphalt shingles or aggregate surface build-up membranes] do not shed snow as well as slippery surfaced standing seam metal roofing.  A sloped metal roof system can be installed directly over the lower flat roof, minimizing business disruption.  The cost differential of adding a sloped metal roof system over an existing flat roof Vs. removing and disposing of the old roofing materials and replacing it with a built-up or modified bitumen roof can be recovered in a few years.

The new roof’s underpinnings include engineered steel framing installed over the existing roof’s framing members to create a sloped plane. It can be designed either as a practical low-slope for discharging rainwater or as an architectural steep-slope for enhanced aesthetics with a ventilated attic space for housing rooftop mechanical systems [prevents accumulating snow next to exposed equipment].  The system is clad with an attractive, durable  standing seam metal roof.

Sustainable Results

If properly maintained, the sloped metal roof system will last up to 50 years and reflect over 80% of the solar energy when coated in a wide variety energy efficient “cool” colors. Adding un-faced fiberglass insulation in the newly created attic space will conserve HVAC energy.  The new roof is also ready for an easy future installation of solar panels.

Design flexibility enables a systems approach to enhancing entryways and other parts of the building with a seamless integration of the new aesthetically pleasing metal roofing system.

 

References:          

Snow induced roof failures and prevention methods

FEMA Snow Load Safety Guide