How to Waterproof Prefabricated Slab Houses

Waterproofing of prefabricated slab houses requires comprehensive measures in terms of slab joint treatment, roof blocking, and bathroom drainage. Specific measures are as follows:

1. Strictly treat the slab joints of prefabricated floors to prevent horizontal water seepage The floors of prefabricated slab houses are assembled from prefabricated components, and the slab joints are weak points for waterproofing. If the waterproofing in water-using areas such as kitchens, bathrooms, and balconies is not done properly, moisture may spread horizontally through the slab joints to other spaces, causing wall dampness, mold, and even leakage. Therefore, it is necessary to strictly implement waterproofing techniques for walls and floors:

• Waterproof layer construction standards: Waterproof coatings should be applied evenly to ensure the surface is free of sand holes and gaps. The drainage lines (such as slopes around floor drains) should be qualified, with straight edges to avoid water accumulation.
• Waterproofing heights in key areas: The waterproofing height on the walls of shower areas should be at least 1.8 meters, while the waterproofing height on the walls of other water-using areas should be no less than 30 centimeters. The floor waterproofing should cover the entire area and extend up the walls to a certain height.
• Treatment of dead corners: Areas such as wall corners, pipe roots, and floor drains should be reinforced with sealant or additional waterproof layers to prevent water from seeping into the slab joints through gaps.

2. Blocking treatment of roof prefabricated slabs to solve inter-slab leakage For roof prefabricated slabs that cannot be blocked by slotting, it is necessary to focus on solving the blocking problem between the slabs:

• Rigid waterproof layer: Lay a reinforced concrete rigid waterproof layer on the roof to reduce the risk of leakage by increasing the structural self-waterproofing capacity.
• Flexible waterproof layer: Add a flexible waterproof membrane or coating on top of the rigid waterproof layer to form dual protection, adapting to minor deformations of the roof and avoiding leakage caused by cracks.
• Node sealing: Seal the nodes on the roof, such as parapet walls, chimneys, and outlet pipes, tightly with waterproof sealing materials to prevent water from seeping in at the joints.

3. Secondary drainage in bathroom backfill layers to prevent water accumulation and leakage If water accumulates in the bathroom backfill layer and cannot be discharged, long-term soaking will damage the waterproof layer and cause leakage. The following measures should be taken:

• Secondary drainage system: Install hidden floor drains or drainage channels at the bottom of the backfill layer, connecting to the main drainage pipe, so that water seeping into the backfill layer can be discharged through the secondary drainage outlets.
• Reserved waterproof inspection ports: Reserve inspection ports during the construction of the backfill layer to facilitate later checks on whether the drainage is smooth. If water seepage is found, repairs can be made promptly.
• Selection of backfill materials: Prioritize the use of lightweight, permeable materials (such as ceramsite) and avoid using construction waste and other materials that are prone to water accumulation and can damage the waterproof layer.

By implementing these measures, the waterproofing performance of prefabricated slab houses can be effectively improved, extending the service life of the building and ensuring居住 (living) safety.