Cold-Climate & Snow-Load Roofs
Northern roofs: freeze-thaw, ice damming and the snow guard layout that keeps a sliding sheet off the entry porch.
Freeze-thaw and absorption
The relevant property is water absorption. Dense, low-absorption slate—Buckingham, Vermont unfading, Peach Bottom—handles freeze-thaw cycling indefinitely. Soft, high-absorption slate delaminates. Every batch we sell is sounded, and we grade for northern service where it is relevant.
Ice damming
Slate does not cause ice dams; inadequate ventilation and insulation do. Detail a self-adhered membrane at the eaves to well above the interior wall line, and fix the attic before you fix the roof.
Snow guards
Guards are a load calculation, not a decoration. Layout depends on pitch, roof length, ground snow load and what is below—entries, walkways, gutters and mechanical units. We supply copper and bronze pad-and-prong guards and fence rail systems, and salvaged pre-1940 guards for landmark work.
Talk it through with us
Call 225-954-8393 and describe the roof. We will tell you what is realistic.
