How to Install Water-swelling Rubber Waterstop Strips – Full Version

4. Concrete Pouring — Final Protection of the Waterstop

4.1 Concealed works’ acceptance before casting

4.1.1 Acceptance contents and standards

A supervisor or owner’s representative must accept the work before casting. Check the model and specs. Center the location on the joint. Ensure overlaps are at least 50 mm and that the surface condition is intact. Record checks per standards (e.g., GB50208) and sign off before allowing concrete placement.

4.1.2 Participants and records

Participants: contractor’s technical lead, quality inspector, supervising engineer, and owner’s rep. Keep written concealed work acceptance records with signatures and photographic evidence.

4.2 Protection during casting

4.2.1 Prevent direct contact of vibrators with waterstop

Do not allow vibrators to strike the waterstop. Maintain at least 10–15 cm distance and use small-diameter pokers near the waterstop. Use “quick in, slow out” vibrator technique; supervise vibrator operators strictly to avoid damage.

4.2.2 Ensure full concrete encapsulation.

Ensure concrete flows to fully surround the waterstop without exposing the top or sides. The recommended minimum cover around the embedded waterstop is ≥ 50 mm. Pour in layers and avoid cold joints.

4.2.3 Layered pouring and vibration requirements

Control pour layers to 300–500 mm depending on slump and vibrator effectiveness. Proper vibration ensures density; insert the vibrator into the next layer by 50–100 mm to achieve interlayer bonding. Verify that there are no voids or honeycombing by observation and tapping.

5. Quality Control and Protection of Finished Work

5.1 Quality control during construction

5.1.1 Incoming materials inspection

Inspect incoming batches per contract. Randomly sample for dimensional tolerance, appearance, and expansion properties. Send suspect batches for third-party testing if required. Reject non-conforming batches.

5.1.2 On-site saw inspection of critical steps

Check key processes (substrate prep, fixing, joint treatment, and casting). Supervisors should measure overlaps and inspect critical details in person (witness testing).

5.2 Finished product protection and later inspection

5.2.1 Prevent premature swelling

Cover installed waterstops with tarps to shield them from rain or construction water. Also, don’t install or cast in the rain. If exposed, replace or rework affected areas.

5.2.2 Water-holding or spray test

After concrete reaches design strength, conduct water-holding tests (≥48 hours) for tanks or spray tests (≥2 hours) for non-holdable structures. Have inspectors check for leaks on the opposite face.

5.2.3 Leak repair and remediation

If leaks appear, identify root cause (joint, damage, honeycombing). Small leaks can be fixed with polyurethane or epoxy injections. For larger defects, you might need localized demolition. Then, install new waterstops. Document repairs and retest.

6. Notes & Safety Requirements

6.1 Environment and storage

6.1.1 Temperature and humidity requirements

Install above 5°C and in dry conditions. Low temperatures reduce adhesive tack and elasticity. Take heat measures in cold environments and avoid high humidity exposures during installation.

6.1.2 Storage and transportation

Store rolls indoors, off the floor, under cover, labeled with batch info. Avoid sunlight and moisture. Handle gently during transport; do not drop or crush.

6.2 Construction safety & occupational health

6.2.1 Personal protective equipment (PPE)

Require helmets, gloves, safety shoes, and masks for dust operations. Use chemical-resistant gloves and goggles when working with adhesives or grout materials.

6.2.2 Safe operating procedures

Enforce tool safety (earthing of power tools), scaffolding and fall protection, and fire safety for flammable materials. Keep site tidy and maintain clear walkways.

Summary & Final Recommendation

To ensure long-term waterproof performance with water-swelling rubber waterstop strips, follow these guidelines closely. Also, maintain strict quality control, accept proper concealment, and protect the finished product.

Focus on these key areas:

• Material acceptance

• Substrate preparation

• Proper jointing (laps and corners)

• Mechanical or adhesive fixing methods

• Careful protection during concrete work

Document every acceptance and test result to ensure traceability and quality assurance.