Bentonite
Sodium bentonite clay, supplied in panels or geotextile-encased sheets, which swells on contact with water to form a dense self-sealing gel against a structure.
On an actual building
It self-seals around minor punctures and settlement movement, which is valuable below grade where nothing can be inspected afterwards. It needs confinement to seal.
What we most often have to correct
That it works in any groundwater. Brackish and saline water inhibits the swelling the system depends on — a real constraint across coastal Mumbai.
Terms that come up alongside this one
- HDPE Membrane
High-density polyethylene sheet with a coated face, laid before concrete is poured so that the concrete bonds mechanically to it..
- Box Type Waterproofing
A continuous barrier wrapping an entire below-grade structure — beneath the raft, up every retaining wall and sealed above ground level — so the structure effectively sits inside a sealed box..
- Geotextile
A permeable fabric used in construction to separate, filter, protect or drain.
More systems terms
Bentonite — questions we get asked
What does bentonite mean in waterproofing?
Sodium bentonite clay, supplied in panels or geotextile-encased sheets, which swells on contact with water to form a dense self-sealing gel against a structure.
Why does bentonite matter on a real project?
It self-seals around minor punctures and settlement movement, which is valuable below grade where nothing can be inspected afterwards. It needs confinement to seal.
What do people commonly get wrong about bentonite?
That it works in any groundwater. Brackish and saline water inhibits the swelling the system depends on — a real constraint across coastal Mumbai.
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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