The two types of cementitious coating: Crystalline and flexible:
Broadly speaking, cementitious coating can be divided into two types – crystalline and flexible. Both include proprietary blends of crystalline powder material containing cement and silica their formulations
CRYSTALLINE CEMENTITIOUS WATERPROOFING:
Crystalline coating is composed of cement, specially treated quarts (or silica), and proprietary chemicals. When combined with water, it undergoes a reaction and forms a crystalline structure that permeates and fills pores, micro cracks, and capillaries in concrete. This effectively blocks off those channels that would otherwise allow the ingress of water and damaging chemicals. Crystalline coatings are resistant to hydrostatic pressure and chemicals, and can be used for both positive and negative sides of water-retaining concrete structures.
Application: Crystalline coating works like a surface treatment, diffusing through the surface of the concrete and bonding with it. It can also be included in the wet concrete before pouring, providing waterproofing in its own matrix, or sprinkled onto the wet slab.
FLEXIBLE CEMENTITIOUS WATERPROOFING:
Also called polymer-modified cementitious waterproofing, this is a breathable, flexible, and versatile option that is can be used for a wide range of applications including foundation walls, water storage tanks, basements, secondary containment bunds, swimming pools, digesters, pumping stations, sewers, and the protection of marine structures. This versatility is down to the ability to include the powder cement admixture in a range of polymer coatings.Flexible cementitious coatings provide waterproofing for positive and negative side installations, can be used for crack bridging, and are breathable.
Application: Flexible cementitious coatings are two component – mix the powder component with the liquid binder component then, when properly combined, apply it by airless spray, brush, trowel, or skid leveller. Can be reinforced.
The benefits of cementitious coatings:
The waterproofing you choose needs to match the requirements of your project. No one coating will work for every situation, and the wrong one can lead to costly repairs and reworks. Cementitious waterproofing has the benefit of a wide range of suitabilities and strengths, including:
- Monolithic – Cementitious waterproofing provides a seamless coating system
- Abrasion resistant and weather resistant – Important where wear or exposure is an issue
- Chemical resistant – Can be used where chemical spills or storage is necessary
- Excellent bonding capability – Bonds to porous and non-porous surfaces
- Works with both negative and positive side pressure
- Resists carbon dioxide and chloride ion diffusion – Prevents concrete cancer and spalling
