How water-based damping coatings reduce vibration and noise: the basics for buildings
A water-based damping coating uses water as its diluent. Once applied it forms a soft, elastic film that absorbs vibration energy through viscoelasticity and also weakens the transmission of sound to some degree.
How it differs from solvent-based coatings
Traditional damping coatings are often thinned with organic solvents such as toluene and xylene, which release harmful gas during application and curing. A water-based system is thinned with water and is generally less volatile, which can help reduce VOC release, but water-based alone is not a VOC or health guarantee; results depend on the formulation and documented measurements. The applied film is soft and elastic; crack resistance and absorption of external force depend on the formulation, substrate and test results.
Vibration mechanism
The coating contains polymers with viscoelastic behaviour. Under vibration the polymers deform and generate internal friction, converting vibration energy into heat. Factors that affect damping include the viscosity of the coating, the coating thickness, and the composition, curing time and application method.
Sound-insulation mechanism
The polymers absorb sound energy and turn it into a small amount of heat, fillers obstruct the path of sound, and the flexibility and sealing of the film help reduce sound transmission. The sound transmission class (STC) is commonly used to assess sound insulation.
A note on use
Vibration and noise in a building come from many sources, and a coating is only one part of the whole scheme. Whether it fits has to be judged against the substrate, the coating thickness, the frequency range and the acceptance criteria.