01/24/2026
Ice Dams are ridges of solid ice that form along roof eaves, created when melting snow refreezes on cold overhangs.
They are primarily caused by heat leaking from the house, causing uneven roof temperatures, resulting in trapped water that seeps under shingles, causing interior damage, mold, and mildew.
Key Facts About Ice Dams
FORMATION PROCESS:
Heat from the attic warms the upper roof, melting snow.
As this water runs down the colder eaves (not heated by the house), it freezes, building a dam.
The “DAM” Effect:
The ice build up prevents melting water escaping, creating a pool that works its way under shingles, plywood, and into insulation, causing ceilings and walls to leak.
Common Causes:
Insufficient attic insulation (allowing heat loss) and poor ventilation are the primary culprits. Clogged gutters can worsen the problem, but are not always the root cause.
Risk & Damage:
Beyond leaks, ice dams cause water damage, mold/mildew growth, structural damage to roofs, and ice build up in gutters, which can cause them to tear off.
Prevention Measures:
Insulate and ventilate:
Keep the attic floor, roof deck, and knee walls insulated to keep the roof cold.
Remove Snow:
Use a long handled (roof rake)
to remove snow from the roofs edge.
Keep Gutters Clear:
Remove debris to allow water to flow.
Safe Removal:
Avoid using hammers, axes, or salt. (which kills landscaping).
Use a roof rake, a specialized steamer (hired professional),
or a pantyhose filled with calcium chloride to melt a channel through the dam.
