How Waterproof Coatings Work?

Waterproof Coatings work by creating a continuous film that blocks water from penetrating or diffusing through. The polymer used in these coatings has a molecular structure with gaps of about a few nanometers. Since a single water molecule has a diameter of only 0.4 nm, it can pass through these gaps. However, water in nature usually exists in clusters due to hydrogen bonding, forming larger groups of water molecules. These larger clusters have a difficult time passing through the polymer gaps, which is the main reason why the coating can prevent water from getting through. Additionally, the coating may have hydrophobic properties, further preventing water from passing.

The Right Application Method for Waterproof Coatings

Is applying multiple layers of waterproof coating the key to better water resistance? Not necessarily. Applying a coat that is too thick can lead to cracking issues. From a cost-effectiveness perspective, applying too thick a layer prolongs the work period and increases labor and material costs, which is not economical. Conversely, if the layer is too thin, it is susceptible to mechanical damage and cannot withstand certain levels of pressure or movement. Over time, a thin layer will also age more quickly and lose its waterproof effectiveness.

So, how thick should the waterproof layer be for effective protection? The required thickness varies depending on the type of waterproof coating used, but generally, a thickness of 1.5 to 2 mm is recommended, with a usage rate of about 1.5 to 2 kg per square meter. This ensures good waterproof performance.

To achieve the correct thickness, it’s important not to rush and try to reach the required thickness in one coat. The principle of application is "thin coat + multiple layers." Typically, two coats of waterproof coating are needed, applied in a crisscross manner from top to bottom and from far to near. When applying the second coat, make sure the first coat is completely dry to avoid missed spots.

It's also crucial to apply the coats in a cross pattern to ensure complete coverage. Additionally, it's essential to take protective measures before the waterproof layer is fully cured—avoid walking on it to prevent damage, and if it gets punctured, repair it promptly.

During application, pay special attention to protecting entrances and wall areas to prevent contamination of the waterproof layer. By following these proper application methods and precautions, you can ensure the quality and effectiveness of the waterproof layer, providing reliable protection for home renovations and setting the stage for the next steps.