TL;DR
Ice and water shield is a self-adhering rubberized-asphalt underlayment applied to roof decking at eaves, valleys, and penetrations, where its membrane seals around fastener shanks to block water backed up behind ice dams or driven by wind. The IRC requires this ice barrier in cold regions, extending from the eave edge to at least 24 inches inside the exterior wall line.
What it means
Ice and water shield is a self-adhering rubberized-asphalt underlayment applied to roof decking at eaves, valleys, and penetrations, where its membrane seals around fastener shanks to block water backed up behind ice dams or driven by wind. The IRC requires this ice barrier in cold regions, extending from the eave edge to at least 24 inches inside the exterior wall line. Solar installers prize roofs that have it because rack lag bolts pass through a self-sealing layer; without it, eave leaks are the classic February claim.
Where it sits in the glossary
Ice and water shield is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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