Ice-and-water membrane at eaves: protection, not a cure
Understand the self-sealing underlayment role: limit leakage during backed-up water without fixing the cause of ice dams.
VERT / GREEN
During reroofing, use tear-off access to inspect decking, eaves and membrane details.
JAUNE / YELLOW
The membrane improves water tolerance, but air sealing, insulation and thermal control remain priorities against ice dams.
ROUGE / RED
Adding more membrane as the only response to recurring frost/condensation/ice dams hides the cause and can let other damage continue.
Quick triage
What the professional checks
The roofer/envelope specialist checks membrane extent, decking, flashing, air sealing, insulation and the actual cause of ice dams.
Official sources
Checked 2026-08-23
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