Drainage
Inspection chambers, soakaway crates, geotextile membrane, underground drainage fittings, and channel drains — the below-ground products that move foul water to the sewer and surface water to a soakaway, and which building control inspects every joint of.
Channel Drain (Threshold Drain): The Strip That Stops Your New Bifolds Flooding the Kitchen
UK guide to channel drain at flush thresholds. ACO ThresholdDrain, AS350, BrickSlot. Installation, Building Regs Part M and H, outlet routing, costs from £29/m.
Geotextile Membrane: The Filter Fabric That Keeps Soakaways and Sub-Bases Working
UK guide to geotextile membrane for soakaways and driveway sub-bases. Why it isn't DPM, why Wickes weed fabric won't do, GSM grades, prices, and 300mm overlap rule.