The right manhole cover is chosen with four questions: (1) what passes over it → EN 124 class; (2) chamber opening in mm → clear opening; (3) theft/odour/unauthorized-access risk → material and locking; (4) which authority spec applies → marking and certificates.
Step 1 — Load Class
Think of the heaviest vehicle that can cross: B125 footpaths, C250 kerbside, D400 anywhere trafficked. Details in our EN 124 guide.
Step 2 — Size (Clear Opening)
Size means the frame's clear opening, not the lid's outer diameter. Man-access chambers use Ø600 mm; valve and meter chambers use 300–500 mm. Measure the chamber mouth and check the frame seating dimensions in the product table.
Step 3 — Material & Hardware
| Need | Recommended |
|---|---|
| Heavy supervised traffic | Ductile iron D400 |
| Theft risk (telecom, lighting) | Composite or locked cast |
| Power distribution chamber | Composite (non-conductive) |
| Odour/water sealing | Gasketed cover |
| Frequently opened point | Hinged or lightweight composite |
| Coastal/corrosive setting | Composite |
| Gardens, green areas | Plastic or B125 composite |
For the material dilemma see Cast Iron vs Composite.
Step 4 — Certification
The surface must carry the cast EN 124 class mark, standard number and maker's name. Public works require certificates and test reports — request them at quote stage.
Pre-Order Checklist
- Class matches the spec (one up when in doubt)?
- Clear opening matches the chamber?
- Cover + frame together, same manufacturer?
- Lock/gasket/hinge needs set?
- Quantities and delivery programme confirmed?
Every cover's class, opening, weight and drawing is tabulated in our catalogue; use the quote form for multiple items at once.
Sık Sorulan Sorular
How is a manhole cover measured?
Measure the chamber's clear opening — not the lid's outer diameter. Ø600 mm is standard for man access.
Round or square?
Round for round chambers — it cannot fall through. Square/rectangular suits valve chambers and wide openings.
Can I buy the cover without the frame?
Not recommended: the class test certifies the cover-frame set, and mixed frames rattle and wear early.
Best anti-theft solution?
Composite covers first (no scrap value), bolt-locked cast covers second.
When is a gasketed cover needed?
Near buildings where odour must not escape, and on lines where surface water must not enter the chamber.
[{"q": "How is a manhole cover measured?", "a": "Measure the chamber's clear opening — not the lid's outer diameter. Ø600 mm is standard for man access."}, {"q": "Round or square?", "a": "Round for round chambers — it cannot fall through. Square/rectangular suits valve chambers and wide openings."}, {"q": "Can I buy the cover without the frame?", "a": "Not recommended: the class test certifies the cover-frame set, and mixed frames rattle and wear early."}, {"q": "Best anti-theft solution?", "a": "Composite covers first (no scrap value), bolt-locked cast covers second."}, {"q": "When is a gasketed cover needed?", "a": "Near buildings where odour must not escape, and on lines where surface water must not enter the chamber."}]