Brownfield materials matched to contamination class.
Ground gas membranes, geotextile, structural waterproofing, contaminated fill, and remediation materials matched to your site's BS8485 characteristic situation (CS1–CS6). BBA certificate references included — your verification test passes first time.
B1 through B6 — full brownfield coverage
Categories will appear here once seeded.
Most CS2 sites use the wrong membrane grade
The classification problem
BS8485:2015+A1:2019 classifies brownfield sites from CS1 (lowest risk) to CS6 (highest). Most UK brownfield sites are CS2 — Amber 1 under NHBC. The required membrane grade and sub-floor ventilation differ significantly between CS1, CS2, and CS3 — and developers consistently buy CS1-grade products for CS2 sites.
The cost of getting it wrong
Wrong membrane grade means verification test failure under CIRIA C735. Failed verification means NHBC LQ03 condition not discharged — your warranty is refused. Units cannot be sold. We match your contamination classification to the correct certified system before procurement.