ASTM-Rated Safety Covers
Safety covers are distinguished from standard winter covers by their structural rating: ASTM F1346 requires that a compliant safety cover support at least 485 pounds over any 5-square-foot area, preventing a child or adult from becoming submerged if they step or fall onto a closed cover. Standard winter covers provide no such support — a person who falls onto a winter cover is at serious risk of entanglement and drowning, because the cover wraps around them and traps them at the water surface.
Safety covers come in two primary materials: mesh and solid. Mesh safety covers allow water to drain through the cover into the pool, eliminating standing water on the cover surface. Solid safety covers block debris and UV light more effectively but require a submersible pump to remove accumulated rainwater and snowmelt. For Boston's climate — significant snow load potential and spring rain — mesh covers are generally preferred because they eliminate the weight and structural risk of accumulated surface water.