Unisorb® IB-500 Isolation Pad material is manufactures in two densities:
IB – 500 – S2: a less dense material which is used to isolate the walls of the inertia block.
IB – 500 – B1: a more dense material which is applied to the base surface of the foundation, usually in two layers. Both materials are manufactured in 1/2″ thick sheets and are used layered where greater thickness is desired.

This isolation material is protected from moisture migrating from fluid concrete by a water resistant covering, which provides a tough abrasion and puncture resistant surface.