When you work on manholes, you know that there is certainly a difference between manhole covers, and not all of them are created equal. In fact, there are many different kinds of covers, and each one has its place. To make your decision though, you need to weigh where you are, and what the manholes in your area will be dealing with on a yearly basis. To make the best decision you possibly can, we recommend following our three guidelines to the best manhole covers:
Capacity refers to how much of a load can consistently cross over manholes. For example, a C class cover should be used where there are vans and trucks over 10 tonnes, while an A class is okay for gardens and other pedestrian areas, as they have a threshold of about 2.5 tonnes. If there are any manholes in your driveway, your best bet is probably a B class, which supports five tonnes.
Many people don’t realize it, but manhole theft is a serious issue. While it does happen quite often in the United States, one of the biggest issues was in Calcutta, India, where over 10,000 covers were stolen over the course of just two months. Officials replaced them with concrete covers, but these were stolen as well. Composite manhole covers have zero scrap value, which means they are much less likely to get stolen.
As with any product you want to find the best possible quality in a product as you possibly can. Composite covers can last upwards of 20 years with normal maintenance. Compare this to the 10 to 15 year lifespan of other cover types and you can see the benefits!
Are you looking into upgrading your manhole covers soon? What do you think are the most important qualities?