One, Polyurethane Waterproof Coating Application
1、Process Flow
- Substrate cleaning → Detailed finishing work → First coat application → Second coat application → Waterproof layer inspection and acceptance → Surface finish application.
2、Construction Method
1) Mixing: Carefully mix the polyurethane waterproof coating kit (A and B components) according to the instructions, using a clean, dry handheld electric mixer. Mix thoroughly (mixing time should not be less than 15 minutes). The quantity should be determined reasonably based on the construction speed, ensuring that the coating can be applied within 20 minutes after mixing.
2) Apply the first coat of coating (horizontally): After detailing and applying the first coat of coating, ensure the film is completely dry. Apply the first full-surface coat evenly, avoiding any localized buildup. Use multiple coats and scuffing to ensure the coating and substrate do not trap air bubbles.
3) Apply the second coat (in a vertical direction): After the first coat has dried sufficiently (typically to the point where it is no longer tacky to the touch), apply the second coat. The application direction should be perpendicular to the first coat. Allow each coat to dry completely before applying the next, until the desired thickness is achieved.
4) After waterproofing is completed, conduct a 24-hour water retention test.
Two. Construction of Polymer Cement Waterproof Coating
1、Process Flow
Substrate cleaning → Apply primer → Detail finishing → First coat application → Second coat application → Top coat application → Waterproof layer inspection and acceptance → Protect the facing layer construction.
2、Construction method
1) Mixing: According to the instructions, first pour the liquid material into the mixing bucket. Gradually add the powder material while continuously stirring with a handheld electric mixer for at least 3-5 minutes, ensuring that the mixture is completely homogeneous, forms a paste-like consistency, and contains no lumps or particles. Note that the mixed material should be used within 3 hours after mixing.
2) Apply a roller-applied primer: To enhance the bonding between the coating and the substrate.
3) Apply the first coat of coating: After detailing work is completed and the coating is completely dry, apply the first coat of the main coating. Ensure even application without any localized accumulation, and apply multiple coats to eliminate air bubbles between the coating and the substrate.
4) Apply a second coat of coating: After the first coat has fully cured (typically when it is no longer tacky to the touch), apply a second coat of coating. The application direction should be perpendicular to the first coat. Allow the surface to dry completely before applying the next coat, until the desired thickness is achieved.
5) Topcoat Application: The final coat is applied by troweling a diluted, water-based coating onto the surface to enhance the smoothness and gloss of the coating. When applying the topcoat, use multiple coats of waterproof coating to ensure complete waterproofing.
6) After the waterproofing layer has completely dried for 24 hours, a water retention test should be performed.