Concrete joints below ground are a prime entry point for water. Stopping that infiltration demands a positive, active barrier, not just a passive resistance. Pasco Aquastop delivers certainty in these critical areas, transforming a potential leak path into a permanently sealed barrier, even under pressure.

Why this product exists

Leaks in basements, lift pits, or tunnels start small. They escalate into structural degradation, demanding costly remediation. Pasco Aquastop exists to prevent this from the outset. It’s a flexible hydrophilic polymer rubber waterstop, specifically engineered for non-moving construction joints and penetrations in concrete structures below ground. Unlike traditional PVC or rubber waterbars that rely on complex welding or split forming, Aquastop integrates a bentonite clay mechanism. On contact with water, its charged microscopic platelets attract water molecules, initiating a controlled expansion of 100-300%. This forms an impermeable, self-healing, pressure-tight seal. As hydrostatic pressure increases, these platelets compact further, reinforcing the seal against water ingress.

The numbers that matter

• Hydrostatic Head Resistance: >70m (25 cycles): This isn't just water resistance; it’s a direct measure of performance under extreme pressure. A 70-meter head means Aquastop reliably holds back water in deep underground structures, even through repeated wet/dry cycles.
• Expansion: 100-300%: This controlled expansion is the core of its self-healing capability. It ensures the waterstop actively fills voids and irregular surfaces, accommodating minor shifts without compromising the seal.
• Elongation: >450%: Combined with expansion, high elongation means the material remains flexible and robust, even when subjected to movement within the joint, maintaining integrity rather than cracking under stress.
• Operating Temperature Range: 40°C to 80°C: This wide range ensures performance reliability in Australia's varied climates and internal conditions of underground structures, from cool subterranean environments to warmer enclosed spaces.

What it's like to use

Installation is straightforward, designed to simplify a complex waterproofing task. Surfaces must be sound, clean, and dry, free from contaminants and standing water. Apply a compatible adhesive, such as Pasco Aquastop Adhesive, along the concrete surface. While the adhesive remains tacky, press the Aquastop firmly into place, ensuring good contact. Joins are simply butt-ended, forming a continuous barrier without the need for welding or complex overlaps. Crucially, do not pre-hydrate the waterstop or submerge it before concrete placement; its activation must occur in situ.

Where this product excels

Pasco Aquastop excels in demanding below-ground waterproofing applications where long-term performance is critical. It is a proven solution for sealing non-moving construction joints and details in:

• Concrete foundations and basements: Forming a primary watertight barrier in lift pits, retaining walls, and sub-grade concrete slabs.
• Civil infrastructure: Securing construction joints in tunnels, box culverts, underground stations, and manholes against persistent water ingress.
• Irregular surfaces and penetrations: Its malleability allows it to conform around pipes, conduits, and other penetrations, or to bridge minor irregularities in concrete, ensuring a continuous, positive seal where rigid waterbars cannot.

How it fits in a real system

In critical systems like capping beams, construction joints, and penetrations, Pasco Aquastop is typically the first step in the waterproofing sequence. It is cast into the concrete itself, establishing a primary, active water barrier before any other membrane or detailing layers are applied. This ensures the joint itself is sealed from within, providing robust protection against hydrostatic pressure that external systems might struggle to contain alone.

Choose this when

• You need a permanent, active waterstop for non-moving construction joints in below-ground concrete structures.
• The application requires a self-healing barrier that expands to fill voids and seal against hydrostatic pressure up to 70 meters.
• The joint needs a waterstop that simplifies installation by eliminating welding and split forming.
• You are sealing around concrete penetrations or along irregular concrete surfaces where traditional waterbars are unsuitable.
• The specification calls for a potable water safe, non-toxic waterstop.

Don't use this when

• Not for: Expansion joints. Aquastop is designed for non-moving construction joints, not for accommodating structural expansion or contraction.
• Not for: Saltwater or organically contaminated groundwater, unless specifically approved by Pasco Construction Solutions. Contaminants can impair the bentonite’s expansion properties.
• Not for: Applications without minimum 75mm concrete cover. Adequate confinement is essential for the waterstop's expansion and sealing mechanism to function correctly.
• Not for: Use as a post-applied surface sealant. This is a cast-in waterstop, requiring full encapsulation within the concrete joint for optimal performance.