Waterproof Membrane Installation on Bridge Slab in Sydney

The Waterstop Solutions NSW team in Sydney recently provided an effective and durable solution to a leaking concrete bridge slab from which the occupied area underneath suffered water ingress during rainfall.

Water was leaking through shrinkage cracks* from the above-mentioned concrete bridge slab, into the gift shop and restroom areas that are situated below the bridge. Unfortunately, during wet weather events, this resulted in the loss of stock, revenue and productivity for our client.

Why was the bridge slab lacking waterproofing?

The bridge lacked effective waterproofing prior to Waterstop Solutions NSW being brought on board because a suitable membrane with the ability to withstand heavy vehicle traffic, the exposure to environmental and chemical stresses had not been available to our client.

The solution

Based on the requirements and the desired results for this site, we selected to install a heavy-duty, trafficable, UV-resistant, slip-resistant, ultra-premium elastomeric membrane coating system that is specifically designed for waterproofing concrete slabs and protecting occupied areas underneath from water damage. This membrane coating system comprises of 4 coats including primer.

Thorough surface preparation before installing the membrane system to all penetrations and junctions is the key to success.

Before applying primer plus 3 coats of the membrane, the following preparation was carried out:

1.  Removed all steel plates from the surface of the bridge.
2. Concrete Preparation: Concrete is required to be free of laitance** which otherwise may inhibit sufficient adhesion. Due to the significance of the adhesive bond of the primer, all concrete surfaces were shot blast prior to any coating application.
3. The primer assists in preventing bubbling or blistering, ensuring the durability of the system.
4. After the primer was cured, three (3) coats of the membrane system were applied and detailed to all penetrations and junctions.
5. The system is supported by manufacturer warranty for 15 years and extendable for a further 10 years with a maintenance application.

* Concrete shrinkage cracks

Whilst concrete shrinkage cracks commonly occur during rapid early drying, they rarely impair the strength of a concrete element. However, with subsequent drying shrinkage, thermal movement and/or loading, the cracks can be deepened, widened and/or extended.

The cracks in this bridge slab led to water ingress problems by acting as a passageway for moisture and dissolved salts.

If this issue had been left untreated, it could potentially lead to rusting reinforcement steel, concrete deterioration and spalling. The corrosion of reinforcement steel leads to reduced resistance of the steel bars, which depending on severity, may negatively affect the load-bearing capacity and service life of the concrete.

** Laitance: A weak, milky layer of cement and aggregate fines on a concrete surface that is usually caused by an over wet mixture, overworking the mixture, improper or excessive finishing or combination thereof.

Are you interested in finding out more about the various remedial building services we are providing?

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Waterstop Solutions Capability Statement is now available to download as PDF. (The image is clickable and opens up a link to our Capability Statement). 

Good maintenance begins with a proactive approach to maintain, keep, preserve and protect a building. 

It takes licenced remedial waterproofer and leak sealing experts like us at Waterstop Solutions to ensure that the pathways for water to ingress are properly sealed off. A depth of technical knowledge and experience, along with a proud reputation for integrity and reliability, has made Waterstop Solutions the go-to company for many Defect Managers working for major construction companies across Queensland and New South Wales.

We at Waterstop Solutions have the technical and practical expertise to diagnose the source of the leak and will provide you with our recommended solution to achieving an effective, high-quality, long-lasting repair to stop the water ingress with minimal disruption

We believe in and are committed to always delivering high-quality solutions by utilising the right products and techniques for each specific project combined with our industry-leading know-how on tap. We have a large talent pool of specialist leak sealing and concrete repair technicians with Certificate III in construction waterproofing in Queensland and New South Wales that are extensively trained in our systems and project execution methods.

The leadership positions on every Waterstop Solutions project are operated by highly qualified, certified and experienced industry professionals. Our in-house skills and expertise gained from more than 60 years of industry experience provide a full range of high-quality remedial waterproofing and concrete repair works to commercial buildings, civil infrastructures, industrial sites and residential properties. From waterproofing diagnostics, preventative and remediation solutions – All of our waterproofing solutions are quality guaranteed.