Earthing Compound B2

B2 (used where there is a permanent water table)
Sodium Bentonite …………60% by mass
Gypsum ………………………40% by mass
Swells greatly (approx 600%) when wetted from dry state & shrinks greatly when drying occurs from wet state causing the formation of extensive cracks and voids.
The resistivity of B2 when wet is relatively low – typically 1-4 Ω.m and it has moderate water retention.