Manhole Covers – Do I need PVC, Steel or Cast Iron?
Manhole covers are created in a various number of materials to suit any and every need. Choosing the correct material for your application means your installation will remain safe and secure, so it’s crucial to get this right.
The three most common types of manhole covers are made from cast or ductile iron, steel and polypropylene (PVC).
Cast Iron Manhole Covers
Cast iron manhole covers are the strongest and most durable covers on the market. They are often able to carry maximum load ratings of up to 90 tonnes when choosing the highest-class option. Thanks to their strength, these manhole covers are ideal for high-speed areas, and areas of high traffic such as public car parks and main roads, as they’ll last longer under constant use.
Steel Manhole Covers
Galvanized and stainless steel manhole covers are lightweight yet an incredibly sturdy and strong alternative to cast iron manhole covers. Easy to install, they are able to withstand enough weight to make them suitable for domestic driveways and applications (around 17 tonnes). This means, they are not suitable for heavy traffic use such as on motorways.
PVC Manhole Covers
PVC, or polypropylene manhole covers are the cheapest and lightest manhole covers we stock. They are commonly used for light traffic applications, such as gardens and walkways. They can’t, however, be used in heavy traffic applications due to their load rating.
This is because the static mass of vehicles is very different to the load exerted when the vehicle is turning and braking - this can sometimes in fact be up to 3 or 4 times the static mass!
This then means that even in principle if your vehicles weigh less than the load rating, in practice, they are still far too heavy and too much force will be exerted through the wheels in movement, compromising the structural integrity of the manhole cover.
To find out what load our manhole covers can cope with take a look at our Manhole Cover Loading information.
Each of these materials will have their own range of classifications and load rating classes, therefore it’s important to do your research and figure out exactly what you in your application. If you’re ever unsure, choose a manhole cover in a class above what you think you need – going lower can have serious safety and security implications if breakage occurs.
For more information about our range of manhole covers, or help to decide which type you need, do get in touch.