How to Protect Waterproof Material Properly to Avoid Water Leakage?

During the engineering construction, there are five reasons may cause the basement leakage including improper metal waterstop setting, improper pour strip concreting, improper waterproof material protection, poor through-wall pipe area sealing and improper outdoor grade waterproof closure height. Here, we’d like to discuss the water leakage arising from improper waterproof material protection.

During the basement construction period, waterproof materials are easy to break and cause water leakage after application due to its long retention period and multiple subsequent procedures. According to our analysis, waterproof material leakage may arise from the following reasons.

• Waterproof protection measures at the basement waterproof guide wall are not fully implemented. For example, if the mortar protective layer is not completed in time, it will lead to insufficient protective layer thickness and strength.
• During the floor structure construction period, no dedicated passageway is reserved. Construction workers step on and damage the waterproof protective layer when they are in and out or handle materials.
• When cutting the split bolts on the basement external wall, the bolt head exposes out and pierces the waterproof layer later.
• When removing the basement exterior wall scaffolding, improper operation causes waterproof layer damage.
• When backfilling the slot, the truck dumps directly, resulting in excessive backfill thickness and waterproof layer cracks.
• When the slot is backfilled, the area from the outdoor grade to the waterproof closure is not properly protected and waterproof layer exposes for a long time, causing waterproof material damage.

Improper waterproof protective layer protection

Truck dumping waterproof protective layer damage

Waterproof material puncture

All reasons mentioned above will lead to serious water leakage. We must take the following measures to address the water leakage.

• Before pouring the basement exterior wall, construction workers and small materials from non-lane areas are prohibited.
• Before conducting the floor reinforcement construction, a special-assigned person shall be appointed to check the waterproof protective layer (especially the guide wall part) and repair it timely if any damage is found.
• During the backfill construction period, the waterproof protective layer shall not be directly applied to the top of the basement exterior wall. Generally, the protective layer shall be about 1.5 m above the backfill surface.
• Backfilling shall be carried out in layers, and truck direct dumping is strictly prohibited.
• When the slot is backfilled, the vertical waterproofing between the outdoor grade and the waterproof closure shall be timely protected with polystyrene boards. When the waterproof layer construction on the top of the extended basement is finished, fine stone concrete protective layer shall be concreted timely.
• When the waterproof construction on the side and top of the guide wall is completed, the waterproof materials shall be covered with soil timely for protection. The side and top of the guide wall shall be plastered timely for protection.
• When the split bolt heads on basement external wall are cut off, check all bolts one by one along the axis. Make sure there is no bolt head exposure. Seal the bolt heads with mortar, and the sealing part shall be leveled with the external wall.
• When the basement exterior wall scaffolding is removed, a comprehensive inspection shall be carried out along the axis. Mark the damaged part clearly and repair it in time.
• Brick protection wall is preferred for the basement exterior wall waterproof layer protection.
• If possible, a three-section sealing screw is preferred.