What is Polyurethane Waterproofing?

When come to the image of polyurethane waterproofing coating, many people may curious about what is polyurethane. However, polyurethane is a plastic material, which exists in various forms. It can be tailored to be either rigid or flexible, and is the material of choice for a broad range of end-user applications such as:

insulation materials, adhesive materials, and coating materials, etc.

Single Part Waterproofing Coating

As to polyurethane waterproof coating there is single part waterproofing coating which is is a reactive moisture-curing one-component polymer based waterproof coating. It used isocyanate and polyether as the main raw material, mixed with plasticizer, solid agent and other additives and produced through the reaction of high temperature dehydration and polymerization by using advanced production technology. It is widely used for floor waterproofing, roof waterproofing and wall waterproofing works.

Two Part Polyurethane Coating

And two part polyurethane coating which is a reactive moisture-curing two-component polymer waterproof coating consisting of A/B components. The A component is a polyurethane prepolymer, and the B component is a water-based curing agent. When using, the A/B components are mixed according to a certain ratio, brushed on the surface of the construction after mixing, and cured into a continuous, flexible and seamless rubber waterproof layer through reaction.

Unlike other waterproofing systems like sheet membranes and liquid applied membranes, this polyurethane application requires comparatively less skill and supervision. Application is fast and this type of treatment can be used for post construction applications as well.

Detailed methods for surface preparation and application are prescribed by the product supplier and often supervised by them in large project applications. Waterproofing is an expensive business, still it is better to prevent leakages and take all precautions during construction stage itself.

Advantages of Polyurethane waterproofing systems

Easy and fast installation

Seamless and continuous finished surface

Long term durability and wear resistant 

UV and weather resistant

Resistant to alkaline cleaners, battery acid and fuels

Polyurethane Waterproofing Application Procedures

Thoroughly clean the construction or working surface and is made free of any foreign materials;

Any cracks on the surface preparation bed is cut to V section, cleaned and filled with portland cement or other caulking materials or crack tapes. The surface must be neutralized by removing alkalinity through the means of acid application

Try to apply a polyurethane primer coating to the surface to serve as an adhesion coat. It is allowed to dry for at least 8 hours.

After the above procedures the brush-apply the 2 component polyurethane waterproofing coating after mixing as per design ratio. Each coat is allowed to dry for at least 12 hours before applying the next. Recommend to apply 2-3 layers to form a 1.0-2.0mm thickness waterproofing rubber layer

The PU coating is continued 150 mm up the parapets or walls. It should also be continued at least 100 mm into the rainwater pipes

The final Polyurethane coat is sprinkled with a layer of 300 micron of sand.

Post time: Jun-24-2021