TL;DR
An exterior waterproofing membrane is the seamless barrier applied to the outside face of a foundation wall — spray-on rubberized asphalt, sheet-applied bentonite or HDPE, or troweled polymer — that blocks liquid water under hydrostatic pressure, a step beyond the thin damp-proofing coat code minimally requires. It is installed during construction or after excavating an existing foundation, typically paired with a dimple drainage board and footing drain.
What it means
An exterior waterproofing membrane is the seamless barrier applied to the outside face of a foundation wall — spray-on rubberized asphalt, sheet-applied bentonite or HDPE, or troweled polymer — that blocks liquid water under hydrostatic pressure, a step beyond the thin damp-proofing coat code minimally requires. It is installed during construction or after excavating an existing foundation, typically paired with a dimple drainage board and footing drain. Excavated retrofits cost many times an interior drain system but fix the wall from the wet side.
Where it sits in the glossary
Exterior waterproofing membrane 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.
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