DJ Membranes Ltd Ground Gas Protection Specialists

Specialist
membrane installation
you can rely on

DJ Membranes Ltd installs ground gas protection membrane systems to BS 8485 and NHBC requirements on brownfield and contaminated land sites across the UK. Every job backed by full RAMS and a signed Certificate of Handover.

Get a Quote ↗ 📞 Call Us
16+
Years Industry Experience
BS8485
Compliant Installations
100%
Jobs with Handover Certificate
What We Do

Complete gas membrane installation,
from sub-base to sign-off

We supply and install ground gas protection membrane systems for housebuilders, main contractors, and geo-environmental consultants — handling the full scope from membrane laying through to detailed penetration sealing and handover documentation.

🛡️

Membrane System Installation

Supply and installation of ground gas protection membranes to perimeter, infill, and gridline configurations, fully in accordance with the geo-environmental specification and current manufacturer installation guidance.

Visqueen Cordek Permagard BBA Certified
🔧

Detailing & Penetrations

Gas-tight sealing to all service penetrations, columns, pile heads, manhole and inspection chamber surrounds, threshold junctions, starter bars, and perimeter upstands — using purpose-made detail components to maintain continuity.

Service Penetrations Pile Heads Upstands Junctions
📋

Quality Documentation & Sign-Off

Photographic record taken before any area is covered, full visual inspection of all joints and detailing, and a signed Certificate of Handover issued to the client's site representative on completion of each defined area.

RAMS Provided Photo Record Handover Certificate
Why DJ Membranes

What sets us apart from a general groundworker

Ground gas protection is a specialist discipline. The quality of the installation determines the long-term safety of the building's occupants — which is why we focus exclusively on this work.

16+

Years of specialist experience

Our technical director has installed gas protection membranes on brownfield, contaminated, and radon-affected sites throughout his entire career.

NVQ2

Qualified, competent operatives

All installation work is carried out by operatives holding or working towards NVQ Level 2 in Ground Gas Membrane Installation, and holding valid CSCS cards.

100%

RAMS on every job

Every site gets a job-specific Risk Assessment and Method Statement before work starts. We don't reuse generic documents — your site, your spec, your RAMS.

BS8485

Code-compliant installations

We work to BS 8485 and NHBC guidance, and coordinate with the geo-environmental design specification before every installation to ensure compliance.

The Process

From enquiry to handover

A straightforward process built around clear communication with you and the principal contractor at every stage.

1

Enquiry & Specification Review

Send us the geo-environmental report and design drawing. We review the specified membrane system, gas protection level, and site conditions before pricing.

2

Priced Quotation

We provide a fixed, itemised quotation with clear inclusions and exclusions — broken down by area, detailing, and protection board where applicable. No hidden extras.

3

Installation

RAMS briefed and signed before work starts. Membrane laid to spec, all joints and penetrations inspected before the area is protected or covered by follow-on trades.

4

Handover & Documentation

Photographic record provided and a signed Certificate of Handover issued. You get the paperwork you need for sign-off — first time, every time.

Who We Work With

The specialists who specify us

We work as a specialist subcontractor across the full supply chain — from early-stage specification through to on-site delivery.

Main Contractors

We're a reliable specialist subcontractor you can bring in when the groundworks spec includes gas protection. We work to your programme and your site rules, and give you the documentation you need.

Housebuilders & Developers

From a single brownfield plot to a multi-phase residential scheme, we handle gas membrane installation for housebuilders working to NHBC requirements on radon-affected or contaminated sites.

Geo-Environmental Consultants

We understand the spec you write. We install to BS 8485 and coordinate with your gas protection design, and we'll flag any site condition discrepancies before work starts rather than after.

Groundworks & Civils Contractors

Need a specialist to handle the membrane element while you focus on the groundworks package? We slot into your programme as a specialist subcontractor and hand over a signed certificate ready for your client.

Ready to get a price? Send us your spec and we'll turn around a quotation fast. Contact us today →

Get In Touch

Talk to us about your project

Whether you have a spec ready to price or you're at the early planning stage, we're happy to discuss your requirements. We aim to respond to all enquiries within one working day.

📞
Jordan Griffiths 07452 960811
📞
James Godfrey-Clarke 07824 721893
✉️
Email [email protected]
📍
Base Location Forest of Dean, Gloucestershire — covering the UK
🕐
Office Hours Monday–Friday, 7:30am–5:30pm