Use B125 (12.5 tonne test load) for driveways and light-traffic areas, C250 within 500mm of the kerb, and D400 (40 tonne) on carriageways and car parks. Always match the location to the minimum class defined in BS EN 124.
Selecting Load Classes & Sizes for Access Covers and Gratings
Manhole covers and drainage grates in this range include solid-top ductile iron lids, recessed tray covers for paving, galvanised steel options in 5 tonne and 10 tonne ratings, compact polypropylene covers, and matching frames in common clear openings such as 320mm, 450mm, 600mm × 450mm and 600mm × 600mm. Typical uses span pedestrian areas, driveways, car parks and carriageways, with selections guided by BS EN 124 load classes (B125 for driveways, C250 near kerb channels, D400 for roads). These products pair naturally with Sewer Pipe & Fittings when completing inspection points on new runs, and with Manhole Lifting Keys for safe removal and maintenance on site.
Recessed tray covers accept block paving, flags or screed to blend access points into the surface while maintaining load capacity; installers typically bed the frame on a sand and cement mortar and match the finished level with the surrounding surface. Where surface water capture is required at kerb lines or channels, open pattern grates link with Line Drainage and Land Drainage to manage runoff and protect the network. For service routes, covers and grates also interface with Underground Ducting for power and comms, maintaining secure access to draw pits and junctions.
Selecting or replacing a lid is based on the clear opening (internal chamber size), not the outer lid dimensions; common materials include ductile iron for higher traffic areas, galvanised steel for lighter applications and recessed finishes, and polypropylene for light duty chambers. Compliance is defined by BS EN 124 parts 1–6 across materials, with markings that indicate the class and manufacturer. These covers are typically sited over 110 mm/160 mm inspection chambers and gully pots, providing secure access while resisting movement under load.
Manhole Covers & Grates FAQ's
Measure the clear opening, the internal width × length (or diameter) of the chamber, not the external lid size. Record in millimetres and match this value to the product specification to ensure correct seating and support.
Yes. Set the frame on a firm mortar bed, level to the finished surface, then infill the tray with blocks or flags on a semi‑dry screed, keeping the tray removable and the joint gap clean for lifting.
A manhole cover fully closes an access opening for inspection or maintenance; a gully grating is open‑pattern to admit surface water into the drainage system while preventing debris from entering.
Yes. Double sealed and locking covers create an odour tight seal and secure the lid to the frame, useful for internal floors, patios over chambers, or areas where tamper resistance is needed.