Additional Information on Manhole Covers
There are several different types of manhole cover and frame products for a range of applications, from plastic, cast iron or ductile iron, galvanised steel or composite products all at different prices. Feel free to search through our categories in which the manhole covers have been sorted to make finding the correct manhole covers, tools or products easy for you.
Manhole cover and frame products are a valuable construction element that provides several functions for the drainage system. Usually fitted onto an inspection chamber, the products enable maintenance workers to gain access to telecom lines or an inspection chamber for the drainage system.
Weight classes for manhole covers products are as follows:
A15 - 1.5 tonne loading.
Very light duty for pedestrian areas such as pedestrian driveways, patios, gardens or pedestrian foot paths or to block access to a small drain or inspection chamber. Usually made from plastic or steel. Usually the lowest cost manhole cover. Most recessed covers for block paving are A15.
B125 12.5 tonne loading.
Light duty. Ideal for occasional light pedestrian traffic with domestic pedestrian driveway thresholds. Used for a drain or inspection chamber. Usually galvanised steel, ductile iron or composite. Mid range.
C250 - 25 tonne loading.
Medium Duty. Perfect for lightly trafficked areas with slow-moving vans and cars and services, some recessed covers for block paving available. Usually ductile iron or cast iron, steel or composite material.
D400 - 40 tonne loading.
Heavy Duty. Suitable for heavily trafficked areas, highways, and main roads such as public car parks
E600 - 60 tonne loading.
Heavy Duty. Recommended for heavy-duty areas like warehouse applications, loading bays and industrial estates. Usually come at a high price.
F900 - 90 tonne loading.
Extreme heavy-duty applications such as airports and docks, usually come with a higher price tag.
Tips Before Buying:
Over the years the lid will wear out, they become weak because of exposure to the elements. The products eventually break, especially if they’re made of plastic or steel.
Broken lids allow drain odours to leak from drainage systems and are risky for vehicles and pedestrians, so the products must be replaced.
Here are the key factors to consider when buying a replacement:
All manufacturers use a similar technique to measure their lids: They are classified by their clear opening, which is the opening that they’re made to conceal.
For security reasons, it’s imperative that the replacement manhole covers are fit for the purpose and loading capacity required, and this boils down to the areas that they are to be fitted, and the traffic in the area.
Plastic, Ductile Iron or Steel?
As long as you stick to the guidelines as mentioned above, the decision is yours. Traditionally most manhole covers were made from ductile iron, but with modern-day advanced technology, the options are unlimited, and offer similar loading performance.
Galvanised manhole covers are easily installed and lightweight but can be rated up to 17 tonnes, so they are very versatile. On the flip side, a cast iron drain cover and plastic manhole cover and frames are dark in colour, so they’re perfect drain covers for tarmacked driveways. Once you find out the correct weight loading capacity and measurements the choice is yours! Plastic or steel lids are usually the cheapest option.
Polypropylene Inspection Chambers, Drain Covers and Access Covers
For those who own new properties, there is a high probability that the manhole cover might be on top of plastic inspection chambers as opposed to brick ones.
In such instances the width of the chambers must be measured, placing a tape measure across the inside to get the diameter (it’ll most likely be round). Then all that is required is to search for and buy manhole covers and frames to suit the measurements of the chambers (usually 320mm or 450mm in diameter).
Another thing to keep in mind is that you still have to ensure your drain cover is of the correct weight class when mounted on a polypropylene chamber! This is especially important when buying gully grates, because these grates will get heavy traffic and are used on public roads.
Block Paving and Patios
Recessed manhole covers are just a metal tray that lets you lay out a slab or blocks inside to match the surrounding area. Usually made from galvanised steel recessed manhole covers are also available in different loads and sizes, so if you’re having your driveway block paved, replace your lidaround the same time - just ensure that your recessed drain cover is of the right weight class.
Installation Tips and Hints
Once the correct drain cover and frame and any other required items or materials have been sourced a builder, drain installer or other capable person should install the drain covers. The drain covers and frame should be bedded in concrete and levelled correctly. The concrete should be allowed to cure for at least three days before any weight is put on to the drain covers and frame.
Can a square lid be fitted into a circular chamber?
Yes, there’re a few that are round to square, meaning they’ll fit in round or square chambers. These include the 300SR, and the T1G3, to name a few.
Why did a forklift break my heavy-duty lid?
Well, a forklift has rock-hard wheels, which exert pressure differently to typical pneumatic, so your manhole cover frame must be specifically designed to suit this.
How do I know which size I need?
All sizes are measured by the clear openings inside the frames, as this is the only true constant between manufacturers’ designs.
I have the correct measurements of my clear opening size, but I can’t find a match, why?
This is because your manhole cover is old-fashioned and in imperial measurements. However, we can provide custom-made solutions with covers made to the exact specs you need, including the correct load rating or in a custom measurement.
Can you give me any pointers on the installation process?
If you’re still hesitant after reading this comprehensive guide, feel free to get in touch with us. Search for our contact page to contact us.
I need to get into my access chambers regularly, is this possible?
Of course, some have inbuilt lift keys. However, the best way to get easy access is to order lids with hinges.