Euclid Chemical HEY'DI K-11 Cement Based, Crystalline Waterproofing Treatment. HEY’DI K-11 is a breathable, two-part, polymer-modified, cement-based system for waterproofing concrete and masonry. HEY’DI K-11 has a texture and consistency similar to concrete and may be brush or spray applied. HEY’DI K-11 becomes an integral part of the wall and waterproofs the negative or positive side through a crystallization process. HEY’DI SB is the bonding agent used with HEY’DI K-11. It improves adhesion and flexibility, and reduces the permeability of the system. HEY’DI K-11 must be allowed to cure before applying a finishing floor system.