How to Repair Leaks in Prefabricated Slab Houses

Leak repair methods for prefabricated slab houses include asphalt treatment, adding a layer of tiles, using professional waterproof materials, full-coverage method, and partial repair method, as detailed below:

Asphalt Treatment

Melt the asphalt into a liquid state and pour it onto the leaking prefabricated slab. Advantages include good waterproof performance and relatively simple construction that does not require complex tools or techniques. Disadvantages are the limited warranty period, as leaks may reappear after about 3 years, necessitating regular maintenance and re-treatment.

Adding a Layer of Tiles

Add a layer of tiles on top of the prefabricated slab to form an additional waterproof layer. Advantages include good waterproof performance and high durability, enabling long-term resistance to rainwater erosion. Disadvantages are the high cost, as tiles need to be purchased and construction fees paid, along with relatively complex construction that requires professional tile installers and a longer construction period.

Using Professional Waterproof Materials

It is recommended to use polymer cement-based waterproof coatings/slurries. Construction Method: First, prepare the base surface where waterproofing is to be done, ensuring it is firm, flat, clean, and free of debris and dust. Then, use a brush or roller to evenly apply the waterproof material to the base surface, typically requiring two coats with each coat not exceeding 1mm in thickness. Pay special attention to treating wall corners into rounded shapes before applying the coating. Pipes passing through walls should be sleeved and holes filled with leak-stopping compound to ensure waterproof effectiveness.

Full-Coverage Method

For leaking roofs, apply waterproofing to the entire roof surface. Preferred material is hot-melt type roll materials, which are resistant to aging and high temperatures and suitable for roof application. Before construction, clean the roof surface and apply a cold primer. During laying, start from the drainage outlet and move upwards, heating and moving simultaneously. The best condition is when the heated roll material leaves no obvious footprints when walked on, and black grease appears on both sides of the roll material.

Partial Repair Method

• Locate the Leak: Leaks in prefabricated slab roofs usually occur at the joints between slabs. After identifying the joint location, knock off the roof protective layer within a width of five centimeters on both sides of the joint, clean up the debris, and sprinkle water.
• Repair the Joint: Use leak-stopping compound to refill the prefabricated slab joint. Quickly stir an appropriate amount of water into the leak-stopping compound to form a porridge-like consistency, pour it into the joint, and use a hog bristle brush to quickly and evenly apply it, coating it to a thickness of 3 centimeters. Finally, pour some water to prevent cracking during solidification, and after solidification, use sand mortar to smooth the joint.