B1
BS8485:2015+A1:2019 · CIRIA C735
Ground Gas Membranes
BS8485 compliant gas membranes for CS1–CS6 sites. Wrong grade for contamination class = verification test failure.
Failure consequence: NHBC warranty refused — units unsellable
Materials
Certified products
| Product | Manufacturer | Certification | Application |
|---|---|---|---|
| Delta Vapour Membrane CS1/CS2 | Delta Membranes | BBA 09/4634 · BS8485 CS1-CS2 | Gas-resistant membrane for CS1/CS2 brownfield sites |
| Proctor Protech 800 CS3 membrane | A. Proctor Group | BBA 14/5167 · BS8485 CS3 · CIRIA C735 | High-performance gas barrier for CS3 Amber 2 sites |
| ITP Powerbase VOC barrier | ITP Membranes | BS8485 CS3-CS4 · VOC verified | VOC and hydrocarbon-resistant membrane for industrial brownfield |
Packages
Brownfield deal packages
Tier 1
Brownfield Gas Protection Pack
£200
48h turnaround
- Contamination class to membrane mapping
- Specific certified product
- BBA certificate reference
- Supplier contact (Delta / Proctor / ITP)
- CIRIA C735 compliance summary
Tier 2
Full Brownfield Materials Schedule
£450
48h turnaround
- B1 + B2 + B3 + B4 materials covered
- NHBC LQ03 ready documentation
- Multiple supplier comparisons
- Installation sequence notes
- 1 revision included
Tier 3
Brownfield Premium with Remediation
£700
72h turnaround
- All B1-B6 categories
- Remediation material specification
- Contaminated fill classification advice
- Specialist contractor shortlist
- 2 revisions included