Swellable vs PVC Waterstops: Which is Best for Your Project?

Water has shaped the world around us. What starts as a trickle can, over time, cause giant canyons. In concrete construction, water can cause big problems as it travels through joints, putting the structure and surrounding areas at risk.

Waterproofing solutions like waterstops can prevent this problem, but for maximum effectiveness, you need to choose the right type for your project.

Illawarra Industrial Supplies has put together this guide on swellable and PVC waterstops, weighing up their advantages and disadvantages in different applications so that your selection meets your long-term requirements.

What Are Waterstops?

In most major construction projects, cast-in concrete is used. This process involves pouring and curing the concrete on-site in its finished position. Waterstops serve as a physical barrier to stop water and other fluids from running along the concrete joints between each pour, or old and new concrete.

Waterstops create a watertight seal in both movement and construction joints, offering protection to the structure and helping to strengthen it. They are categorised into two types: joints without movement (construction cold joints) and joints with movement (dilation joints). Waterstops are most often required in water-retaining structures like pools, or when the joints sit below the water table.

Factors to Consider When Choosing a Waterstop

Before you contact Illawarra Industrial Supplies to discuss your waterstop needs, consider these factors so that we can help you make an informed decision on the best product for your waterproofing project.

• Project location
• Environmental conditions and degree of exposure
• Exposure to chemicals
• Resistance to corrosion
• Performance in low temperatures
• Budget
• Size and thickness of concrete
• Long-term performance requirements
• Adhesive properties
• Ease of application

Understanding the Benefits of Swellable Waterstops

In a construction joint with no movement, known as a cold joint, swellable waterstops are used to generate a strong pressure seal. They are applied between pours, once the slab has set, and a hydrophilic waterproofing sealant is placed on the face of the concrete joint. After the second pour, the strip swells to seal the concrete joints that may be exposed to water.

Swellable waterstops are made from bentonite clay, rubber compounds and polymers. They work to prevent water leakage by absorbing moisture from the environment. Installation is generally straightforward, and the materials ensure a tight seal is maintained by expanding up to 300%.

Why buy swellable waterstops from Illawarra Industrial Supplies?

Illawarra Industrial Supplies stocks a range of swellable waterstops, each with unique benefits. For example, Leakmaster is a gun-applied waterstop paste that provides excellent water sealing without losing its rubber-like elasticity. It offers great compatibility with rough concrete and adheres to other materials like glass and metal. In comparison, Sikawell S2 is a 1-part polyurethane hydrophilic sealant that’s permanently water-resistant through both wet and dry cycles, while Cetseal is low VOC and UV resistant.

When you buy swellable waterstops from Illawarra Industrial Supplies, you can rest assured you will be offered the best advice to choose the right product for your project based on the features you require.

Understanding the Benefits of PVC Waterstops

PVC waterstops are designed for longevity while allowing for movements that cause concrete joints to open and close, such as in expansion joints. Typically, a PVC waterstop is cast 50% in one pour and 50% in the second pour, forming a physical seal in the joint that prevents water from passing in either direction.

They are commonly used as an exterior waterproofing system for framing structures like bridges or buildings. When used in expansion joints, PVC waterstops feature a bulb profile to allow for movement. However, they can also be used for construction joints, but they don’t feature the same bulb profile.

Made from high-grade PVC compounds, these waterstops offer durability and flexibility. They are usually joined at intersections by welding and are resistant to salt and contaminated water. They have the added benefit of chemical resistance, making them suitable for harsh environments.

Why buy PVC waterstops from Illawarra Industrial Supplies?

With uses from dams, sewage tanks and pools to roof decks and underground carparks, PVC waterstops are available in a range of profiles to suit different needs. The Sika Waterbar from Illawarra Industrial Supplies is suitable for high-water pressure areas and is particularly suitable for thinner concrete components. By comparison, our Supercast PVC Waterstops are available in a range of profiles and are designed to minimise site joining with factory-produced intersections.

Whether you’re working on slabs, basements or tunnels, we can work with your selection criteria to find the best product for your waterproofing requirements for any sized project.

Swellable vs PVC Waterstops: A Comparison of Two Types

From cost to effectiveness, both swellable and PVC waterstops have their benefits and disadvantages.

Advantages of swellable waterstops

• Effective compression seal for joints with no movement
• Superior performance in a humid or wet environment
• Can be more cost-effective than PVC
• An eco-friendly choice
• Durable
• Non-swelling types can self-seal, making them ideal for pipes, retaining walls and foundations

Disadvantages of swellable waterstops

• They can deteriorate as the joint cycles from wet to dry
• Can cause blowouts if applied too close to the face of the concrete

Advantages of PVC waterstops

• Ideal for water-retaining structures like pools, dams and tanks
• Versatile
• Strong yet offer elasticity
• High resistance to acids, corrosion and chemicals

Disadvantages of PVC waterstops

• Can become brittle in low temperatures
• Less elasticity than rubber
• Can be harder to install
• Prone to damage during concrete pour

Seal the Deal and Shop Waterstops with Us Today

As their name suggests, waterstops are specially designed to protect concrete structures from water damage. But in order to fulfil their function and provide an effective seal, you need to make the right choice between swellable and PVC.

At Illawarra Industrial Supplies, our highly trained team is more than happy to help you compare products to select the right type and brand for your project, whether it’s a big job or a small one. Learn more about our waterstops range here or call us on (02) 4271 3888 for expert advice.