TL;DR
An isolation joint is a full-depth separation, filled with compressible material, placed where new concrete meets an existing structure, a foundation wall, column, light pole base, or older slab, so the two can move independently without cracking each other. It differs from control joints, which only weaken the slab to steer shrinkage cracks; this one breaks the bond entirely, with no reinforcement crossing it.
What it means
An isolation joint is a full-depth separation, filled with compressible material, placed where new concrete meets an existing structure, a foundation wall, column, light pole base, or older slab, so the two can move independently without cracking each other. It differs from control joints, which only weaken the slab to steer shrinkage cracks; this one breaks the bond entirely, with no reinforcement crossing it. Driveway pours against garage aprons and sidewalks meeting stoops rely on it, and the fiber or foam filler gets topped with sealant where water exposure demands.
Where it sits in the glossary
Isolation joint is part of the Certifications 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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