Cold Joint
An unplanned joint formed when fresh concrete is placed against concrete that has already begun to set, so the two do not knit together.
On an actual building
Unlike a construction joint it is unintended, so it has no water stop and often no surface preparation. It is a direct water path through a structure and a common source of basement and tank leakage.
What we most often have to correct
That it is cosmetic if the surface looks continuous. The discontinuity runs through the section.
Terms that come up alongside this one
- Construction Joint
The interface where one concrete pour meets a previous one that has already set..
- Honeycombing
Voids in hardened concrete where mortar failed to fill the spaces between coarse aggregate, usually from inadequate compaction or congested reinforcement..
- Water Stop
A PVC strip or swellable hydrophilic profile cast into a construction joint to block water travelling along it.
Cold Joint — questions we get asked
What does cold joint mean in waterproofing?
An unplanned joint formed when fresh concrete is placed against concrete that has already begun to set, so the two do not knit together.
Why does cold joint matter on a real project?
Unlike a construction joint it is unintended, so it has no water stop and often no surface preparation. It is a direct water path through a structure and a common source of basement and tank leakage.
What do people commonly get wrong about cold joint?
That it is cosmetic if the surface looks continuous. The discontinuity runs through the section.
Have a building showing this?
If a term on this page describes something you are looking at, a site inspection will tell you how far it has gone and what it needs. It costs nothing.
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