The type of a manhole cover is mainly determined by:

  • strength class;
  • shape;
  • dimensions;
  • components.

There is no legislation establishing the shapes and dimensions that manhole covers must have, so production rules are dictated by the market and customer needs.

KIO composite manhole covers are produced in the following shapes and sizes:

  • rectangular – 900×500 to 1000×558 mm
  • square – 300×300 to 950×950 mm
  • round – Ø425 to Ø1230 mm
  • square grid – 500×500 mm

The components of manhole covers are mainly defined by the market, but there are some features that are imposed by the relevant regulations.



According to EN 124-5, the locking system is mandatory for manhole covers in class D400. Polieco, in this case, uses a screw or spring bar locking system.

Although not required by regulations, class B125 and C250 KIO manhole covers are available with locking systems using a simple screwdriver or spanner.



The class B125 square KIO manhole cover is also available with a flat outer frame. This type is ideal for installation where there is paving composed of paving stones or natural stones.

Also for this strength class, above plastic manholes, a KIO round manhole with a female socket can be used for connection to elevations with diameters of DN 250/315/400/630.

In combination with the KIO 800 D400 cover, a floating cast-iron frame is also available. The floating part of the frame engages within the concrete manhole riser. The system can be raised and levelled during asphalting of the road, always remaining at the same level as the road surface. Furthermore, in the event of temperature variations throughout the year, the floating system is free to move, following the expansion/contraction of the road surface.



Polieco Group guarantees a perfect watertight and odour-tight seal for some models, thanks to a special gasket combined with a stainless steel locking system. A test according to the British technical specification PAS 26 was performed on these models, which involves creating a 50 mm water stagnation above the manhole cover for 7 hours and then applying a 5 tonne load without showing visible signs of leakage. This test was validated by the certification body ICMQ.


Characteristics of manhole covers                            KIO Composite manhole covers