Negative side waterproofing implies the method in which an Integral cementitious crystallizing coating is applied to entire interior surface to make a barrier against the hydrostatic pressure of water and make a damp wall dry from inside.
Sometimes, the name refers to Injection Technique which could be applied on both sides of the wall and is more likely to be categorized under locally waterproofing techniques and is not to be discussed here.
For information about Injection Techniques and Products, please click here.
When leaking infrequently occurs, then Negative Side Waterproofing could be the right choice to avoid a big construction job in your property.
In Negative Side Waterproofing, the preparation of substrate is the primary step and vital for the premium bonding level of old concrete to final waterproof coating, and “to achieve the best grip”.
To provide the unobstructed access of bonding agents to the base substrate materials, any old coatings, paints, dirt and efflorescence should be removed.
Depends on the condition of surface, chemical cleaning products or mechanical means could be used.
A variety of Commercial Cleaning Products are available but most effective way is using a wire brush to scrub the old surface.
All cracks should be found and repaired and the entire surface should be etched entirely for an unsmooth surface to be reached; which allows more grip and easier penetration of “Active Components” in the mixture, through the capillary paths inside the base substrate.
The Crystallizing mechanisms in Negative Waterproofing Mixture acts as capillary barriers which form crystals when they get in contact with water.
This system prevents the penetration of water to the surface layer. In this technique the integrity of final coating, as a main factor for a long-term performance of system, should not be underestimated.
An “Integral Waterproofing System” could manage preventing the water penetration to the surface.
To achieve the maximum performance of coating, thickness should not be less than 2mm.