The why, what and where of waterstops

Architectural details of modern apartment building.

As specialists in leak detection, Danrae Group has a robust understanding of common waterproofing issues – and best remedies. We also know that in waterproofing, the smallest leak can make a huge impact, so it’s crucial to stop it at the source.

Water is most likely to enter a property in tears or at the edges of waterproofing membranes and at property joints and seams. To help prevent this, we typically use waterstops in our solution design.

Waterstops work as a barrier to water ingress in concrete, and while they’re small, they’re very effective. Here’s everything you need to know about the why, what and where of waterstops.

Movement joint on a bridge

Why we use waterstops

While membrane waterproofing is crucial to protect your property, it’s just one part of a thorough waterproofing design. When we provide you with a waterproofing solution, we consider every location in your building – including the rooftop, balconies and planter boxes – and every structural element.

Waterstops are one part of the solution, specifically designed for expansion joints, cold joints and other concrete seams.

Concrete is a substance that naturally expands in heat and contracts in cooler temperatures.

Concrete structures, as such, need mid-structure gaps or separations to alleviate structural stress, which is where these joints come in. While expansion and cold joints help prevent cracking due to movement, they also need to be sealed to ensure they’re not a pathway for water.

Red car driving up to the parking lot through spiral entrance ramp

What are waterstops?

Waterstops are waterproofing components specifically designed to completely seal concrete joints such as expansion joints. There is a wide range available, made from materials including PVC, stainless steel and copper.

Waterstops generally fit into two main categories – to suit non-moving and moving joints. Non-moving joints, such as a joint between footing and foundation, typically need a PVC waterstop that expands when exposed to water, creating a watertight compression seal. There are also mastic waterstops, which are applied with a primer adhesive to create a self-sealing barrier, and crystalline products such as spray-application waterstops.

Mechanical waterstops are usually the option for moving joints, and we would need to install these during the concrete pour.

Our team selects the best choice and brand of waterstop based on the property type and location, the joint type and joint movement requirements, hydrostatic pressure and the likelihood of exposure to chemicals.

Large multi-storey underground car parking garage

Where we use waterstops

We install waterstops at expansion joints and all other concrete seams, to make sure you have a watertight property.

Waterstops are nearly always found in concrete structures, from the rooftop to the basement.

It’s also very important to include them anywhere a joint or seam comes into contact with water. Common applications, as such, also include water tanks and dams, tunnels, lift pits and roof decking.

Expertise for every project

Danrae Group has the expertise and industry know-how to provide waterproofing solutions for strata, construction, civil, commercial and government projects, and we always guarantee our quality.

With an in-house team of waterproofing experts and trades specialists, we also look after end-to-end project management, from diagnostic through solution design, waterproofing, remediation and preventative maintenance.

Please take a look at our articles on waterproofing techniques, and contact us if you need a leading, high-quality and permanent waterproofing solution.

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