BIOKIL 20mm Stud Membrane – High Drainage Waterproof Tanking Membrane (2m x 20m)

The Biokil 20mm Stud Membrane is a heavy-duty waterproof cavity drain membrane designed for demanding basement waterproofing and civil engineering applications where effective seepage control is critical. Its deep 20mm stud profile creates a high-capacity drainage void while forming part of a Type C waterproofing system compliant with BS8102:2009.

Manufactured from durable HDPE, this membrane provides an impermeable waterproof barrier suitable for floors, walls, vaults, tunnels, and below-ground structures. Its exceptional drainage performance and high void capacity make it ideal for projects exposed to severe water ingress or persistent damp conditions.

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Key Features & Benefits

• 20mm stud profile – provides exceptional drainage capacity
• High water void volume – 14L/m² drainage capability
• Type C waterproofing system – compliant with BS8102:2009
• Ideal for severe water ingress – suitable for demanding below-ground environments
• Waterproof and salt inhibiting – protects against moisture and contamination
• Root and contaminant resistant – suitable for civil engineering applications
• Quick installation – easy to roll out over floors and slabs
• Minimal structural disruption – little or no damage to existing structures
• Low and high temperature tolerance – performs from -50°C to +80°C
• Heavy-duty HDPE construction – long-lasting and highly durable

Typical Applications

• Basement floor waterproofing
• High water ingress environments
• Walls and floors in below-ground structures
• Civil engineering projects
• Vaults and tunnels
• Commercial and industrial waterproofing

How the System Works

The 20mm stud profile creates a large drainage cavity between the substrate and finished surface, allowing water to pass freely behind the membrane and be safely directed into a drainage system.

This cavity drain approach manages water rather than resisting it, significantly reducing the risk of waterproofing failure while creating a dry and habitable internal environment. :contentReference[oaicite:0]{index=0}

Installation Overview

Floor Applications

• Apply Biokil Lime Inhibitor to concrete slabs before installation
• Roll membrane directly across prepared concrete floors
• Seal internal and external corners using Biokil Corner Strip Tape
• Overlap sheets by at least three studs to interlock the membrane
• Do not mechanically fix floor membranes to maintain free drainage

Wall Applications

• Install membrane with studs facing the wall
• Drill through the centre of studs and fix using Biokil Brick Plugs with seals
• Seal flanges using Biokil Sealing/Joining Tape
• Overlap joints by at least two stud rows (three in severe wet conditions)
• Use Biokil Sealing Rope and Corner Strip Tape for additional protection

Surface Preparation

All surfaces should be clean, sound, and level prior to installation. Remove any loose plaster, render, or screed and repair uneven areas using a suitable sand-cement mix with additive.

Where mould or fungal growth is present, treat the area with a suitable masonry biocide before installation. In above-ground applications, moisture sources should be addressed using a damp proof course such as Biokil BioDry ProCream.

Finishing Options

Floor Finishes: Basement floors are typically finished with a concrete pour or a minimum 65mm screed over the membrane. Ensure screed moisture content is below 75% RH before applying impermeable floor coverings.

Wall Finishes: Stud wall systems can be installed over the membrane. For project-specific finishes and detailing, consult the Biokil Technical Department.

Vaulted Ceilings & Special Applications

The membrane can be installed on vaulted ceilings and curved structures where required. All mitred joints should be fully sealed using Biokil Sealing Tape, Sealing Rope, and Corner Strip Tape to maintain waterproof integrity.

Flat soffits below ground level should not be lined unless a minimum slope of 10% is present.

Aftercare & Ventilation

The membrane creates a dry and habitable environment in areas previously affected by persistent dampness. However, effective condensation control remains essential in enclosed or poorly ventilated spaces.

Mechanical ventilation systems are recommended to reduce condensation and maintain healthy airflow.

Technical Specifications

Feature	Specification	Test Standard
Material	HDPE	-
Unit Weight	1kg/m²	-
Sheet Thickness	1mm	-
Stud Height	20mm	-
Colour	Black	-
Water Tightness	Pass	EN1928
Compressive Strength	170kN	BS EN ISO 25619-2
Tensile Strength (MD/CD)	416N / 488N	BS 12311-2
Resistance to Static Loading	>20kg	BS 12730
Reaction to Fire	Class E	BS EN 13501-1
Working Temperature	-50°C to +80°C	-
Life Expectancy	Lifetime of structure	-

Available Size

• 2m x 20m – 40m² coverage

Why Choose Biokil 20mm Stud Membrane?

With its deep stud profile and exceptional drainage capacity, this membrane is specifically designed for challenging waterproofing environments where lower-profile systems may not provide sufficient water management.

Ideal for basements, tunnels, civil engineering, and high-risk damp environments, the Biokil 20mm Stud Membrane delivers professional-grade waterproofing performance for long-term protection.