Manhole Cover Replacement Guide

A manhole cover is a removable plate that acts as a lid over a manhole opening. The main purpose is to prevent any person or debris from falling in, to keep out unauthorised persons or animals, and to give access to the underlying drainage for inspection and maintenance. Old or unfit manhole covers pose a danger to both those working on site and people passing by.

Manhole Cover Guide

Modern drainage systems will typically have a plastic chamber riser that the manhole cover connects to.

Shallow Chamber Riser
Shallow plastic chamber riser

Most manhole covers come with both the cover itself and a frame, which is usually bedded on mortar set to a height to make the manhole cover flush with the surrounding ground when it is placed on top. The frame will remain in place while the cover is removed when access is required. The frame will screw onto the riser to hold it in place, and the manhole cover will lock to the frame with the use of securing screws.

Most manhole covers are round, for three good reasons:

  1. The cover cannot be dropped into the manhole, as the diameter will be slightly larger than the manhole itself.
  2. The cover can be rotated easily and will always fit.
  3. The round shape is more able to resist the natural compression forces of the earth around it.

In cases where the appearance of the landscape needs to be maintained, there are also recessed manhole covers (also known as driveway manhole covers). These include a tray where material such as bricks, screed or asphalt can be placed.

Recessed Manhole Cover
Recessed manhole cover

Cover Load Capacities

  • 2.5 Tonnes – suitable for gardens or pedestrian areas
  • 5 Tonnes – suitable for domestic cars (e.g. for driveways)
  • 10 Tonnes – suitable for small trucks and vans

How To Choose The Correct Manhole Cover

Measure the opening size

Manhole covers are measured by the size of the opening when the cover is removed – the distance/diameter between the inside walls of the frame. Measuring the size of the old cover will not be helpful!

Replace the cover and the frame

You should always replace the old frame completely with the new unit with the correct size and loading capacity for your purpose. Fitting a new cover in an old frame may lead to an imperfect fit, which can have safety implications and reduce the lifespan of your manhole cover and frame.

Select the correct loading capacity

Using the wrong load capacity of cover can lead to serious injury. You can avoid safety and financial risk by investing in the proper equipment. Take a look at our range of manhole covers and frames to find the right cover for your needs.

How to install the new manhole cover

Installing a manhole cover is usually a fairly simple process with the right products.

  1. Remove the old frame and the surrounding material.
  2. Level and bed the new frame.
  3. Backfill the installation.
  4. Install the manhole cover.

Drainstore are experts in installing all kinds of drainage systems, including manhole and access covers. If you have any queries or are looking for advice, call us on 01773 767611 or use our contact form.