Water Stop BS - Bentonite Based Swelling Waterstop
BS water stop
Water Stop© BS is a bentonite based waterstop produced to provide watertightness at cold joints in reinforced concrete. It is placed on the joint surface, after which the second pour is carried out and the waterstop remains between the two concrete masses.
On contact with water, the bentonite within the waterstop expands in volume. The expanding material fills the cracks, voids and pores along the joint, closing the path through which water could travel. Its volume recedes as it dries and expands again when it is rewetted.
Water Stop BS Functions
Water Stop© BS works to prevent water from travelling along the surface where two separate concrete pours meet. A cold joint is a region where fresh concrete is placed against hardened concrete, and for this reason no continuity exists in the structure at that point. When the waterstop is placed in this region, it expands on contact with water, conforms to the geometry of the joint and closes the cross section through which water could pass.
Joint Watertightness
Cold joints are the regions where water passage most frequently occurs in reinforced concrete structures. Water Stop© BS prevents this passage by forming a continuous barrier between the two pours. The weakest link in the waterproofing chain of the structure is closed in this way.
Volumetric Expansion
When the waterstop comes into contact with water, the bentonite within it gains volume. This expansion fills the irregularities, cracks and pores on the joint surface with the material itself. Watertightness therefore does not depend on formwork precision or surface evenness.
Continuity at Detail Points
Conventional waterproofing systems struggle to maintain continuity at detail regions such as pipe penetrations, lift pits and architectural recesses. Because Water Stop© BS can be applied along the cross section in these regions, it keeps the waterproofing chain uninterrupted. Since an opening formed at a detail can render the entire waterproofing ineffective, this continuity is of critical importance.
Expanding Filling That Does Not Depend on Formwork Precision
Conventional joint sealing solutions base watertightness on geometric fit. The smaller the gap remaining between the waterstop and the concrete surface, the better the seal, which means formwork evenness and workmanship quality determine the outcome directly. Water Stop© BS removes this dependency. Because the product gains volume on contact with water, it fills the gap itself, so watertightness comes not from the precision achieved at the moment of placement but from the expansion behaviour of the material. Irregularities, fine cracks and pores on the surface are closed by the expanding material. The same behaviour also accommodates movements that occur in the joint later, since every gap that opens is filled again with renewed water contact.
Water Stop BS Features
- Expands on contact with water and fills the joint gap
- Its bentonite based structure expands again when rewetted after drying
- Its flexible structure conforms to joint geometry and surface irregularities
- Does not sag or deform when correctly positioned
- Shows resistance to chemical reactions and impact
- Durable against high temperature variations
- Can be fixed with nails or mastic, requiring no additional equipment
- Provides watertightness without depending on formwork evenness or workmanship precision
- Can be applied without interruption at detail points such as pipe penetrations and lift pits
Frequently Asked Questions
1. What Is Water Stop BS?
Water Stop© BS is a bentonite based waterstop produced to provide watertightness at cold joints in reinforced concrete. On contact with water it expands in volume and fills the cracks, voids and pores along the joint, closing the path through which water could travel.
2. Why Is a Cold Joint a Weak Point in Waterproofing?
A cold joint is the surface where fresh concrete is placed against concrete that has already been poured and hardened. Because there is no structural continuity between the two pours, this surface forms an interface that is open to water passage. Even when the rest of the structure is sound, water can travel through this interface, which is why the joint requires separate sealing.
3. How Is Water Stop BS Installed?
The waterstop is placed on the hardened concrete surface before the second pour and fixed in position with nails or mastic. The purpose of fixing is to prevent the waterstop from shifting during concrete placement. Once positioned, the second pour is carried out and the waterstop remains between the two concrete masses.
4. Are Additional Measures Required at Pipe Penetrations?
Yes. When applied around the inlets and outlets of pipes passing through reinforced concrete, the waterstop must be covered with an epoxy based product. In these areas the concrete cover remains thin, so the expansion of the waterstop can go unrestrained and additional protection is required.
5. Do Weather Conditions Matter During Installation?
Yes. Installation should be avoided in adverse weather conditions. Because the product begins to expand on contact with water, a waterstop placed under rainfall may start expanding before the second pour is carried out and may lose its intended position within the joint.
6. In Which Structural Details Is Water Stop BS Used?
It is used at the connection points of precast concrete elements, underground structural joints, joints between concrete elements, vertical structural joints, pipe joints passing through reinforced concrete, and concrete to steel joints. It is also preferred in reinforced concrete structures exposed to high pressure water.