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Manhole Cover Sizes and Load classes

The application determines manhole cover sizes and load classifications. You must measure the area to ensure a precise fit whether you’re installing a new manhole cover or replacing an old one. Regardless of the load class, if your manhole cover doesn’t fit precisely, you risk compromising the structural integrity and it could fail.

How do you measure manhole cover sizes?

The internal dimensions of the hole, not the manhole cover itself, must be measured in order for the cover to fit snugly over the hole it is concealing. Since millimetres are the manufacturers’ standard measurement unit, it must be done in millimetres for precision. Once you have this measurement, you should explore our selection of manhole covers, just use table below to determine which product is appropriate for your job, or call our helpdesk at 0161 235 1214 to get assistance.

Manhole Cover Sizes

Manhole coverings are available in square and rectangular sizes ranging from 300 x 300 mm to 1200 x 1200 mm. We also offer circular manhole covers with 450mm and 600mm dimensions.

Ductile iron manhole cover weight classes.

The same weight class system that applies to channel drains also applies to ductile iron manhole covers.

ClassMax. weight load (tonnes)Users
A151.5For pedestrian areas including gardens, patios, and driveways, very light duty.
B12512.5Domestic driveway thresholds for family cars, vans and 4x4s
C25025Roads with little traffic and small private parking areas.
D40040Highways, main roads, and heavily travelled sites such public parking lots.
E60060Loading bays, industrial parks, and freight handling yards.
F90090Extremely heavy-duty applications including docks and airports.

Types of manhole covers

Other than manhole covers sizes and load classes, there are a few types of manhole covers to choose from.

Ductile Iron

Over a D400 class, ductile iron manhole covers are sturdy, resilient, heavy-duty covers that are frequently utilised. Cast iron, commonly known as ductile iron, is utilised because of its high strength. This material then lends itself to installation at docks, airports, and other high-use industrial sectors with a lengthy lifespan.

Ductile Iron Manhole cover


Recessed manhole covers are covers with a cut out in the tray that allows for the installation of brick pavement, cement, and screed. In pedestrianised areas where aesthetics are important, this makes it possible for the recessed manhole cover to fit in with its surroundings. In hospitals, workshops, and domestic gardens where homeowners don’t want an unsightly but required manhole cover jutting out, it’s also a viable alternative for internal manhole covers.

Recessed Manhole Cover

Solid top

Manhole covers with a solid top are intended to stand out in the floor. These are generally put in places where having a manhole cover visible would be better for safety and routine maintenance than having one hidden. A visible silver manhole cover with an anti-slip surface is a common example of a solid top. In some cases, depending on where they are situated, they might also be raised. They are simple to distinguish because of the contrast between the solid top manhole covers and the solid floors.

Solid Top Manhole Cover