Background introduction
The basement slab is the lowest structural element of a building and is constantly subjected to groundwater and hydrostatic pressure from below. Since the waterproofing system becomes inaccessible after the concrete is poured, effective protection must be installed before construction. A pre-applied waterproofing membrane is the preferred solution because it bonds permanently with the structural concrete, preventing water migration even if minor settlement or shrinkage cracks occur.
Program description
2. Blinding concrete (if required)
3. Install Pre-laid HDPE Sheet with the bonding layer facing upward
4. Seal membrane overlaps and joints using compatible HDPE sealing tape
5. Reinforce critical details such as corners, pile heads, construction joints, and pipe penetrations
6. Install steel reinforcement
7. Pour reinforced concrete basement slab
Matters needing attention
● Ensure the substrate is smooth, compacted, and free from sharp objects, loose debris, and standing water.
● Install the membrane with the correct orientation and maintain the recommended overlap width.
● All membrane joints and overlaps must be completely sealed before concrete placement.
● Protect the installed membrane from puncture or damage during reinforcement installation.
● Repair any damaged areas immediately using compatible repair materials.
● Concrete should be poured as soon as possible after membrane installation to ensure optimal bonding performance.
● Special attention should be given to pile heads, construction joints, corners, and pipe penetrations to ensure complete waterproof continuity.
● Do not expose the membrane to prolonged UV exposure before covering with concrete.
