Ground Gas Membranes
Be aware of toxic gases
When working below ground, it’s not just water that threatens a structure. Gases such as radon, methane, and carbon dioxide can accumulate beneath buildings, posing serious health and safety risks. Effective protection requires a design that considers both — waterproofing and ground gas protection — from the earliest stage of the project.
Waterproofing & Gas Protection
When working below ground, it’s not just water that threatens your structure — gases such as radon, methane, carbon dioxide (CO₂), and volatile organic compounds (VOCs) can migrate through soil and accumulate beneath buildings.
These invisible contaminants pose serious risks to health, safety, and structural performance. That’s why effective below-ground design must consider both waterproofing and ground gas protection from the earliest stage.
Modern engineering allows the integration of dual-protection systems — combining water-resistant and gas-resistant barriers into a single, continuous envelope. These systems not only prevent water ingress but also stop harmful gases from entering the internal environment.
Every project begins with a site-specific risk assessment and Characteristic Situation Score, determining the exact level of protection required. From there, our CSSW-qualified design team develops a bespoke specification tailored to your site’s ground conditions, drainage strategy, and intended use.
Understanding Ground Gas Protection
Ground gas protection aims to block or safely disperse hazardous gases before they can accumulate beneath or within a structure.
These gases can originate from natural geology, landfill areas, or contaminated brownfield land, and their impacts vary:
-
Radon — a naturally occurring radioactive gas that can increase long-term health risks if inhaled over time.
-
Methane — a flammable gas formed by decomposing organic matter, capable of causing explosive atmospheres in confined spaces.
-
Carbon Dioxide (CO₂) — an asphyxiant gas that can displace oxygen in basements or underground structures.
-
VOCs (Volatile Organic Compounds) — toxic vapours often linked to industrial pollution, affecting indoor air quality and occupant health.
Depending on the site’s contamination risk, protection may include:
-
Gas-resistant membranes – acting as continuous physical barriers against gas and vapour migration.
-
Structural barriers – watertight concrete or reinforced construction that resists gas flow under pressure.
-
Ventilation systems – dispersing gases safely away from occupied areas.
In higher-risk sites, two or more of these strategies are combined to achieve compliance with BS 8485:2015+A1:2019, ensuring full protection against harmful gases and water ingress alike.
Design Integration
Our CSSW-qualified design team creates fully integrated waterproofing and gas protection strategies that work together — maintaining structural integrity while defending against groundwater, soil gases, and environmental contaminants.
By merging BS 8102 waterproofing principles with BS 8485 gas protection design,
ARTI ensures that every below-ground system meets the highest standards of durability, safety, and compliance — protecting both the structure and its occupants for decades to come.