Manholes

Manholes: the access point that protects what is buried

Manholes are the access boxes buried in an installation so you can reach it without breaking up the paving. Inside runs a joint, a branch, a change of direction or a connection that will have to be checked one day, and the manhole is what lets you open up, look and close again. They are used as cable draw pits for low voltage, street lighting and telecoms, and as waste water manholes for foul water, rainwater and irrigation. In this category we bring together the covers that close them, in cast iron and in galvanised steel.

Why a manhole is put in

A buried installation with no access points is an installation that can only be repaired by breaking things. The manhole puts an end to that: it places an accessible void exactly where the installation has a weak point or a branch. In electrical and street lighting networks it houses joints, junction boxes and the run from duct to duct. In drainage it takes changes of fall and of direction, and allows blockages to be cleared without digging. The golden rule is simple: wherever the route turns, splits or joins, a manhole goes in.

Cable draw pits and waste water manholes

They are not the same job. In cable draw pits what matters is room for the bending radius of the conductor, that standing water does not sit there permanently and that the cover can be opened with ordinary tools. In waste water manholes something else rules: the trap, the fall and, above all, the smell. Those are two different demands, and the difference almost always comes down to the cover you choose to close them with.

The cover is the piece that decides

The manhole is buried once; the cover is walked on, parked on and opened for years. That is why it is classified by load capacity under the EN-124 standard, and that is the figure you cannot get wrong. In the catalogue we work with three classes: B-125 up to 12,500 kg, C-250 up to 25,000 kg and D-400 up to 40,000 kg. Each class is meant for a type of traffic —pedestrians and cars, parking areas and hard shoulders, and carriageways with heavy traffic respectively— and fitting a class below what it will have to bear ends in breakage. In the Manhole Covers subcategory you will find the size guide and the detail of each class.

Cast iron or galvanised steel

Cast iron covers are the choice for strength: they take vehicle traffic, they do not deform and they are the ones that cover all three load classes. They are heavy, and that is a virtue when the cover has to stay where it is. Galvanised steel ones play a different part: they weigh far less, the galvanising protects them from corrosion and they allow a recessed build, that is, with a tray that is filled with the same paving —ceramic tile, terrazzo, stamped concrete— so the cover visually disappears into the floor. On a porch, a terrace or an internal courtyard that difference in looks shows.

Sealed and odour-proof manholes

When the manhole is connected to drainage, an ordinary cover lets the smell through. The answer is a sealed cover: a closure with a perimeter gasket that seals the frame against the surround and cuts off the escape of gases. That is what is needed in waste water manholes inside the home, in kitchens, in hospitality premises and anywhere the access point sits in a circulation area. If the access point is out in the open and only cable passes through, you do not need sealing; if it smells, you do.

Tell us what is underneath and we will tell you which cover

If you are not sure which load class applies to you or which size fits the surround that is already concreted in, write to us with the use, the traffic it will have to bear and the size of the opening. We will confirm the reference and availability before you buy.

Frequently asked questions

Do you sell the complete manhole or only the cover?

What we supply in this category are the manhole covers, in cast iron and in galvanised steel. The body of the manhole, which is either built on site or a precast concrete or polypropylene unit, is not in the catalogue. If you need the complete set, write to us and we will tell you which manhole sizes our covers fit.

Which load class do I need?

It depends on what will pass over it. B-125 for pedestrian areas and car parking, C-250 for hard shoulders and parking zones, and D-400 for carriageways with vehicle traffic. When in doubt, go up a class: the extra cost is small compared with lifting the paving to replace a cracked cover.

What is a recessed cover?

It is a cover with a tray that is filled with the same material as the floor around it, so all that shows is the perimeter joint. It is used when the manhole falls within a finished pavement and you do not want a metal square in the middle of it.

Does the same cover work for cables and for waste water?

Mechanically yes, if the load class is right. Functionally not always: for drainage a sealed cover that cuts off the smell is the sensible choice, and for cables a cast iron cover of the corresponding traffic class is normally enough.