Choosing a manhole cover
Most of us walk or drive over manhole covers every day without a thought.
When you need to fit one, a little care at the start means a cover that sits flat and stays safe for years. It comes down to the traffic it will carry and the place it will sit.
The load classes, from A15 to F900
In the UK, makers rate covers and gully gratings under the British Standard BS EN 124. The 2015 edition replaced the 1994 one.
The standard sorts covers into six classes. Each class name gives the test load in kilonewtons that the cover has to withstand in the maker's test. So an A15 cover is tested at 15 kN, and an F900 cover at 900 kN. The classes in between are B125, C250, D400 and E600.
The standard covers openings up to 1,000 mm across. It has separate parts for covers made of cast iron, steel or aluminium, reinforced concrete, composites and plastics.
Matching the class to the place
The standard also describes six kinds of place, from the gentlest to the most demanding. Suppliers set out the usual minimum class for each one like this.
- A15 for areas only people on foot can reach.
- B125 for footways, driveways and car parks that see only the odd vehicle.
- C250 for slow traffic in car parks and on forecourts, and at the edge of a road, up to 500 mm out from the kerb.
- D400 for roads, hard shoulders and other places that cars and lorries use.
- E600 for heavy loads, such as loading bays and docks.
- F900 for very heavy loads, such as aircraft stands.
Covers around the home
Building regulations guidance in England (Approved Document H) asks for inspection chambers and manholes to have removable covers made of a durable material. Cast iron, steel, precast concrete and plastics are all named. The cover should be strong enough for where it sits and should not let air through.
Small, light covers should be fixed down, for example with screws, so that children cannot lift them. Inside a building, a chamber should have a mechanically fixed airtight cover, unless the drain itself has watertight access covers.
Covers on business sites
GOV.UK pollution guidance for businesses asks you to paint manhole covers to a standard code. Blue means surface water. Red means foul water. A red "C" means a combined system, where all the water goes to a treatment plant.
The same guidance suggests painting an arrow on each cover to show which way the water flows. A matching arrow on the ground means a lifted cover goes back the right way round. A simple plan of your drains helps with upkeep and with any spill.
Covers on major roads
On motorways and major trunk roads, National Highways sets extra rules for covers in a standard called CD 534. It has been revised more than once since 2020. Standards for Highways publishes it, along with the other road design standards.
For a pothole or road defect, your local council is the place to report it. National Highways looks after motorways and the major A roads it manages in England.
Before you lift a cover
The space under a cover can hold bad air or fumes. The Health and Safety Executive (HSE) treats an enclosed space like this as a confined space when there is a foreseeable risk of fumes, low oxygen, fire or drowning.
HSE advises avoiding work inside a confined space wherever possible. Where someone has to go in, the work needs to be planned. The people doing it need training, and there should be a plan for getting them out.