Gas Membrane Installation

by Chloe Binns

Safeguarding a building can take shape in many forms, from fitting locks on doors to ensuring fire alarms are installed and regularly tested - but what many can forget about are the threats that you can’t necessarily see or hear or even touch. 

Hazardous gases are silent and invisible, making them difficult to pin down and tackle. Therefore, preventative methods are the best way to protect yourself and the occupants who inhabit the building that is being constructed.

This is where gas membrane installation comes in. Consult HomeFix’s quick and concise guide on gas membrane installation below, for a better understanding of the risks that you’re potentially up against and how to effectively protect against them.Do I need gas membrane? 

Hazardous gases and vapours are a growing challenge for the construction industry, so it is important that before any practical action is taken, care must be taken to determine the gas risks of the site you are working on. 

The harmful gases in question are known as ground gases. Occurring either naturally or as a result of contamination of land, ground gases are found amongst soil particles and predominantly include: radon (Rn), carbon dioxide(CO2), methane (CH4) and Volatile Organic Compounds / Hydrocarbons (VOCs)- although the full range of variants is extensive and possibly infinite.

The prominence of these gases varies across the UK and Ireland and they can be identified through gas monitoring and site inspection. 

Gas membranes are required on high gas risk sites. For more information look below for a breakdown of gases and the industry-standard guidance to refer to. 


  • (Refer to the guidance in BR211)
  • Invisible radioactive gas 
  • Is found everywhere but the prevalence varies
  • Derived from the decay of small amounts of uranium that is present in rocks and soils 
  • Known to increase risk of cancer 

Methane and Carbon Dioxide 

  • (Refer to the guidance in BS 8485:2015+A1:2019)
    • Dangerous when there is a build-up or sudden release
    • Flammable 

    VOC and Hydrocarbons

    • (Refer to CIRIA reports)

    What is gas membrane installation?

    Cracks, construction joints and cavity walls are amongst some of the possible ingress points where these gases can enter the building.

    Gas membranes are typically plastic sheet membranes that act as impermeable barriers to prevent ground gases from passing through them and entering the property. They usually are installed in the foundation stage of construction.

    How does gas membrane work?

    Gas membranes work by preventing the ground gasses from travelling from the soil and into buildings where they could accumulate and expose inhabitants to significant health risks. 

    There are multiple manufacturers of gas membranes, with different types of membranes available to cater to specific needs. These include radon barrier membranes, liquid gas membranes and self-adhesive gas membranes to name a few.

    What you may not know is that many of these gas membranes can also double up as damp proofing membranes (DPM) which possess similar protective properties to prevent moisture damage in the property. These dual-purpose membranes will sometimes be referred to as a radon DPM. 

    This Visqueen gas membrane barrier, for example, protects buildings against methane, radon and carbon dioxide as well as acting as a damp proof membrane.

    Look to our selection of gas membrane barriers to find the right product that suits your needs. HomeFix is a proud, official partner of Visqueen and Capital Valley, featuring reputable Radbar products known for their excellent gas membrane equipment.

    How to fit a gas membrane

    Gas membranes should be installed either above or below the slab of concrete ground floors. This means that they should be implemented early on in the construction process. 

    Additionally, since gas membranes and radon barriers are so vital in the prevention of significant health risks, they must be installed under all applicable building standards and regulations. 

    Here at HomeFix, we stock essential gas membrane accessories such as gas membrane tape in single and double-sided variations to securely bond any joints in the membrane.

    You should ensure that the gas membranes are kept puncture-free, as this kind of damage will mean that it is no longer gas-tight, essentially rendering the barrier useless. 

    Top Hat fittings are also necessary to place over any pipework that may come through the concrete slab and radon barrier sheet. Use these in combination with gas tape to ensure that the installation remains airtight. 

    If you are planning to carry out the installation process yourself, we’d advise looking at our handy Visqueen Radon Installation Guide and Radbar Installation Guide for specific, step-by-step instructions.

    Use our nifty on-site calculators to work out the gas membrane cost per m2. Simply enter the width and length of the area you need to cover and we’ll let you know the number of rolls required, along with the cost. You can find this tool on each gas membrane barrier product page.

    For more information and guidance regarding gas membrane installation and more, be sure to refer to our Gas Membrane Barrier FAQ's

    If you can’t find the answer to your queries or require specific, technical advice, please don’t hesitate to contact us and speak to one of our trained experts.