Allco offers a full range of waterproofing and damp proofing membranes, and understanding their differences before specification is critical. While below-ground bitumen membranes provide a barrier against moisture and vapour, preventing dampness from rising into a building’s structure, Allco's waterproof membranes are designed to resist water ingress entirely, forming a robust protection against water penetration. Selecting the right solution will depend on the specific requirements and conditions of the project.

This article covers the key differences between the CETCO Volclay waterproofing range and Casali Damp Proof Membranes.

CETCO Volclay Range: The ultimate waterproofing solution

CETCO Volclay is a world-leading waterproofing solution designed to provide robust protection against water ingress in below-ground structures. The Volclay range utilises sodium bentonite, a naturally occurring clay with remarkable swelling properties, which expands upon contact with water to form a dense, impervious barrier.

Key features and benefits:

All-weather installation

One of the standout features of the CETCO Volclay range, which includes Voltex and Swelltite, is its ability to be installed in virtually any weather condition, including rain and snow. This flexibility significantly reduces weather-related construction delays.

No priming required

Unlike other tanking membranes, Volclay products do not require a priming layer. They can be installed directly onto compacted slab substrates, saving valuable time and resources.

Pre-applied and post-applied options

Voltex is a pre-applied membrane suitable for use around formwork and horizontal surfaces. Its patented carpet-like geotextile fibres ensure the bentonite stays in place, protecting against wet weather and construction damage.

Swelltite is a post-applied membrane ideal for vertical concrete walls and block work. It combines bentonite with butyl rubber, offering flexibility and resilience, and adheres easily to concrete walls.

Self-healing properties

Both Voltex and Swelltite hydrate and swell upon contact with water, forming a dense, impervious membrane. This swelling action allows the products to self-heal and seal around penetrations and small cracks, ensuring long-term protection against water ingress. 

Casali Damp Proof Membrane: Managing moisture effectively

The Casali Damp Proof Membrane (DPM) range is specifically designed to control moisture in below-ground structures by preventing water vapour from rising into the building. Unlike waterproof membranes, which are designed to resist water ingress entirely, DPMs are ideal for non-hydrostatic conditions where there is no significant water pressure.

Key features and benefits:

Designed for non-hydrostatic conditions

The Casali DPM range is specifically designed to manage moisture in the form of water vapour rather than resist water ingress entirely. This makes it ideal for low-risk project conditions where hydrostatic pressure is not a concern.

Versatile application methods

Casali membranes can be applied using peel-and-stick or torch methods, offering flexibility in installation.

High-quality material

Manufactured from premium modified bitumen, Casali DPMs ensure durability and reliability.

Compatibility and warranty

The Casali DPM range is compatible with Allco’s Volclay Waterproofing range, ensuring seamless integration for comprehensive moisture protection. Allco offers a 20-year product warranty, providing peace of mind to specifiers, builders, and developers.

Product variants for specific needs

• Casali Aderix: Self-adhesive membrane ideal for wall applications requiring a peel-and-stick method.
• Casali Olympia (PBS): Suitable for under-slab applications with torched laps or wall applications.
• Casali Dermafil: Chipped cap sheet membrane for walls with torched applications and transitions to above ground.
• Casali Eradix: Root stop membrane designed for planter boxes.

Choosing the right solution

Selecting between waterproofing or damp proof will depend on the specific requirements and conditions of the project. For instance, if the site is likely to encounter hydrostatic pressure, CETCO Volclay is the ideal choice due to its ability to form a dense, impervious barrier and self-heal around penetrations and cracks, ensuring long-term protection against water ingress. On projects with no water pressure and where managing water vapour is sufficient, the Casali Damp Proof Membrane offers an effective and high-quality solution to prevent water vapour from entering the building

It is also important to consider the weather and site conditions of the project. The Volclay range can be installed in most weather conditions, whereas a rainy day will grind the application of DPM bitumen membranes to a halt, creating delays. Volclay products can be installed in any weather, making them highly versatile and reliable, saving time and money in the long run.

Understanding these differences and benefits will help you choose the best below-ground protection for your project, enhancing the longevity and integrity of your structure. Allco offers a comprehensive range of solutions and has dedicated technical support ready to help you make the right choice every step of the way.