The CM Range

The CM Range by Wykamol stands at the forefront of structural waterproofing technology, providing a fully integrated suite of cavity drain membranes and essential accessories to meet the diverse needs of below-ground waterproofing across both the UK and Northern Ireland. Whether the challenge is groundwater ingress in a basement renovation or damp retention in an older structure, the CM Range offers a high-performance, Type C solution that’s trusted by professionals, contractors, and specialist installers alike.

Recognised for its reliability, compliance, and adaptability, the CM Range includes a variety of membrane types such as CM3, CM8, and CM20 alongside drainage channels, fixings, jetting eyes, plugs, corner pieces, and more. Every component is engineered for maximum performance, ease of installation, and compatibility with BS8102:2022 standards for protection against water ingress in structures below ground.

BS8102:2022-Approved Waterproofing

At the heart of the CM Range’s success is its adherence to British and Northern Irish waterproofing regulations. All products within the system are developed to comply with BS8102:2022, the recognised code of practice for below-ground waterproofing in the UK and Northern Ireland, and the de facto standard for Type C systems in Northern Ireland. This ensures that the CM Range not only delivers robust protection against moisture but also meets the professional and regulatory expectations of architects, surveyors, and warranty providers.

The CM membranes are especially well-suited to create a Grade 3 internal environment (defined as one suitable for domestic habitation) through mechanical drainage and water management rather than relying solely on tanking or coatings. The system allows water ingress to be safely collected and diverted to a sump or natural drain, protecting internal finishes, floor coverings, and building structure over the long term.

CM3 – Lightweight Versatility for Internal Walls and Finishes

The CM3 membrane is a 3mm studded cavity drain membrane ideal for use on walls where a lighter, thinner solution is required. It allows direct application of plasters, render systems, or dot-and-dab plasterboard, thanks to its integrated mesh face. Particularly effective in conversions or retrofits, CM3 is a favourite for professionals working on basement walls, vaulted cellars, or heritage structures where preserving the existing substrate is essential.

The CM3 membrane installs quickly with minimal surface preparation and provides excellent resistance to salts, contamination, and low or high temperature conditions. It is available in various roll widths, including a specialist 1.2 metre version to prevent salt banding near wall bases. When used with Wykamol Brick Plugs or Plaster Plugs and Fibre Tape, the membrane delivers a consistent, breathable damp-proofing solution that transforms wet internal spaces into dry, habitable environments.

CM8 – Increased Drainage Capacity for Challenging Projects

When a greater stud height is required to handle more aggressive moisture conditions, the CM8 membrane steps in with a robust 8mm stud profile. It is available in two key formats – plain membrane and CM8 Mesh Membrane, which includes a bonded HDPE mesh suitable for direct plaster or dry lining finishes.

This membrane is ideal for demanding waterproofing scenarios, such as basement conversions, retaining walls, and projects where deeper cavity space is required to manage persistent or fluctuating groundwater levels. The CM8 membrane is also available in higher-density formats such as HD700, providing greater compressive strength and resilience in commercial or high-traffic installations.

Contractors working in areas of high lime or silt risk often combine CM8 membranes with Waterguard Channels and regular jetting access to maintain performance over time. The membrane is crystal clear, allowing installers to precisely locate plugs and overlaps during application – saving time on site and improving long-term reliability.

CM20 – Maximum Water Void for Heavy-Duty Applications

The CM20 membrane is the most robust in the Wykamol CM lineup, offering a 20mm stud profile and a water void volume of 14 litres per square metre. It’s specifically designed for areas with serious water ingress risk or where substantial drainage flow is required – such as large domestic basements, commercial underground developments, or retaining structures on sloping terrain.

Thanks to its larger cavity depth, CM20 is also highly favoured for use beneath floor slabs and insulation layers. Installers can overlay closed-cell insulation, floor screeds, or floating floors directly onto CM20, creating a multi-layered, insulated waterproofing build-up that remains compliant with BS8102:2022 and NHBC Chapter 5.4. The membrane’s strong HDPE construction resists root intrusion, contamination, salts, and freeze-thaw cycles.

The CM20 Hi-Vis version is especially popular in low-light working environments. Its vibrant yellow finish improves site safety, particularly in cellars and basements, and enhances visibility of joints and seals to reduce trip hazards.

Drainage Channels That Work With the Membranes

Complementing the membranes are Wykamol’s drainage channels, including the standard Waterguard Channel and the Wykamol Floor Drain Channel. These components serve as the engineered backbone of the system, guiding collected water toward a sump chamber or drainage outlet.

The Waterguard Channel features an upstand for placement at wall-floor junctions, while the Wykamol Floor Drain Channel is flangeless, allowing it to be laid centrally across slab floors – ideal for irregular layouts or areas with stepped footings. Each is pre-drilled and manufactured from rigid, impact-resistant PVC for long-term durability in active environments.

Both channels connect easily to a suite of system ancillaries, including T-Pieces, Jetting Eyes, and Swept Corner Pieces. These components make complex installations faster, safer, and more maintainable. Push-fit designs, smooth internal curves, and lime build-up resistance help create an uninterrupted flow path throughout the structure, reducing blockages and long-term maintenance burdens.

Plaster and Brick Plugs

Wykamol’s CM Brick Plugs and CM Plaster Plugs are specialist fixings designed to provide a watertight and mechanically secure attachment between the membrane and the substrate. Brick Plugs are suited for standard membranes like CM8 and CM20, while Plaster Plugs are tailored to mesh membranes like CM3 Mesh and CM8 Mesh, offering a broad head for plaster finishes.

Each plug features a reinforced head to prevent deformation during installation and is available with or without pre-attached thermoplastic elastomer seals. These seals compress upon insertion, ensuring a complete waterproof seal around every fixing point. This attention to detail not only improves system performance but also simplifies installation for contractors, even in tight or awkward spaces.

Enhancing System Performance With Jetting Eyes, Outlets, and Connectors

The CM Range wouldn’t be complete without its essential finishing components. These include Jetting Eyes (rigid and flexible), Stop Ends, 50mm Outlets, Jointing Sections, and Universal Outlets – all of which are designed to improve flow, accessibility, and adaptability of the drainage system.

Jetting Eyes provide vital access for camera inspection and high-pressure cleaning tools. Positioned every 10 to 12 metres, they allow for quick maintenance access and prevent silt or lime buildup within the channel network. The flexible version bends easily around corners and fits wall port applications.

T-Pieces, 50mm Outlets, and Universal Outlets allow for controlled transitions between channel sections and connection to sump systems, gullies, or natural drainage routes. These ensure the Type C system is fully integrated and adaptable to on-site requirements, terrain variations, and design changes.

CM8 Geotextile

A standout addition to the CM Range is the CM8 Geotextile Membrane a dual-layer solution comprising a robust studded HDPE core and a UV-stabilised non-woven geotextile. Designed for horizontal or vertical applications, this membrane is suitable for use behind retaining walls, under ground slabs, or even on green roofs and landscaped terraces.

The geotextile fabric acts as a filtration layer, preventing fine silt from clogging drainage paths while still allowing free water passage. Its combined insulation, compressive strength, and drainage performance make it ideal for applications where water pressure or soil movement could compromise simpler systems.

Because the CM8 Geotextile allows backfilling with excavated earth, it helps contractors reduce site waste while improving waterproofing reliability. Its rugged build and high water flow rate make it a preferred choice for civil engineering works and eco-conscious developments.

Dampstop and Damp Kits

The CM Range also includes convenient all-in-one kits like the Dampstop Mesh Membrane Kit, designed for fast-track damp proofing in domestic settings. Featuring a slimline 3mm stud mesh membrane and accompanying plugs and tapes, this solution enables rapid refurbishment of interior walls, particularly in heritage homes or buildings where traditional plaster is being replaced.

Such kits provide an ideal entry point for DIY users or small-scale contractors looking for a professional, compliant solution without needing to purchase components separately. They’re also widely used by property maintenance teams who need to act quickly and reliably in reactive environments.

Trusted by Specialists Across the UK and Northern Ireland

Whether you’re a contractor waterproofing a basement in London, a structural engineer designing a Type C system in Belfast, or a local tradesperson tackling a damp-proofing job in Glasgow or Bristol, the CM Range provides a solution you can rely on. Backed by the expertise of Wykamol and compliant with modern waterproofing standards, every component of the CM system is designed to make installations faster, safer, and longer-lasting.

With membranes, fixings, and channels engineered to perform as a complete system, the CM Range offers unmatched flexibility and peace of mind. It’s the trusted choice for thousands of professionals working across the UK and  Northern Ireland in new builds, renovations, commercial developments, and heritage restorations.