Vermont's average annual snowfall of seventy to ninety inches creates extraordinary snow loads that accumulate on steep-slope roofs, and the sudden release of these loads poses serious safety and property hazards.
An engineered snow retention system is not an accessory but a critical safety component that must be integrated into the roof design from the initial structural analysis.
Load Analysis and Placement
Snow retention systems must be designed to withstand the specific shear and tensile forces generated by snow creep and glide on each unique roof geometry. Factors including roof pitch, cladding material, solar orientation, and local snowfall data determine the required number and spacing of snow guards. Our engineering team performs a zone-by-zone load analysis that accounts for thermal differentials across the roof plane, ensuring protection at transitions, valleys, and above entry points without exceeding the structural capacity of the roof deck.
Material Compatibility
Snow retention components must be metallurgically compatible with the roof cladding to prevent galvanic corrosion. Stainless steel guards on standing seam metal roofs require isolation shims, while copper roofs demand copper-alloy retention systems. For slate and synthetic slate roofs, we specify snow guards that attach through the sheathing rather than clamping to the slate itself, preventing stress concentrations that could fracture the roofing material during thermal movement.
