Sealing of construction joints in concrete structures is commonly performed by a Dual Seal Water-stop, a Bentonite / HDPE based water-stop which reacts in contact with water by swelling to form a watertight seal.

In contact with water, hydrophilic strips react and swell by up to 300% of their original dimensions to form a compression seal.

It can be installed directly by nailing-down onto surfaces and will swell into honeycombing of concrete or voids up to 12mm deep.

Pipe nozzle penetrations through concrete walls can also be successfully sealed. Dual Seal Water-stop requires a minimum of only 25mm cover so can be placed

beyond the outer layer of rebar to protect this layer, rather than be placed in the centre of the construction joint in the traditional manner.

Changes of direction and end joints are simply achieved by butting together, no welding or adhesives are required.

Most of current producers have Dual Seal Water-stop independently tested up to 30 meters head of water.

Here are few examples from Reinforced Concrete Water Tank where swellable water-stop was successfully used.

Application of Dual Seal Water-stop

Water Reservoir’s Inlet & Surge Shaft

Application of Dual Seal Water-stop

Water Reservoir’s Outlet Shaft & Overflow

Vertical Construction Joint Sealing (Base Slabs)

Vertical Construction Joint Sealing (Base Slabs)

Vertical Construction Joint Sealing (Slabs)

Cold Joint - Sealing

Due to concrete pump malfunction, continuation of concrete pouring could not continue. Loose concrete was removed by air-blasting, chipped, contact joint shaped and dual seal water-stop placed above the upper layer of re-bars.

Cold Joint Sealing

2,5cm distance to the surface.

Horizontal Construction Joints Sealing (Walls)

During concrete installation to Base Slab – a kicker for later Wall is left H=10-15cm. Within the kicker, prior of concrete hardening, a wooden lath is placed to form a groove (3x2cm) where dual seal water-stop will be placed.

Horizontal Construction Joints Sealing (Walls)

Installation of water-stop without a groove.

Horizontal /Vertical Construction Joints Sealing (Walls)

Horizontal Construction Joints Sealing (Walls)

Horizontal /Vertical Construction Joints Sealing (Walls)

Horizontal /Vertical Construction Joints Sealing (Walls)

Horizontal Construction Joints Sealing (Walls)

Base slab with wall kicker and starter bars, groove for water-stop.

Horizontal /Vertical Construction Joints Sealing

Each of the base / roof slab modules (bays) have dual seal water-stop between construction joints.

Pipe-Wall Penetrations

Drain Pipe

Pipe-Wall Penetrations

Drain Pipe prior of water-stop installation

Drain Pipe prior of water-stop installation

Pipe-Wall Penetrations

Drain Pipe after installed water-stop

Pipe-Wall Penetrations

Pipe-Wall Penetrations

Pipe-Wall Penetrations

Outlet Shaft Pipe

Pipe-Wall Penetrations

Dual Seal Water-stop placed on Wall’s Horizontal & Vertical Construction Joints, Overflow Pipe

Pipe-Wall Penetrations

Overflow Pipe with installed water-stop, elastic sealant

Pipe-Wall Penetrations

Overflow Pipe with installed water-stop, elastic sealant

Pipe-Wall Penetrations

Overflow Pipe with installed water-stop, elastic sealant

Pipe-Wall Penetrations

Overflow Pipe after centering and closure of shutter.

Pipe-Wall Penetrations

Inlet Pipes

Pipe-Wall Penetrations

Inlet Pipes

Pipe-Wall Penetrations

Inlet Pipes

Pipe-Wall Penetrations

Inlet Pipes

Pipe-Wall Penetrations

Inlet Pipes

Pipe-Wall Penetrations

Overflow Pipe

Pipe-Wall Penetrations

Overflow Pipe with dual seal water-stop and elastic sealant tape.