Why Are Manhole Covers Round?

By Columbia PrecastNovember 23, 2022No Comments

Why are manhole covers round? Have you ever wondered why they are that shape — and not rectangular or square?

Manhole covers and manholes themselves are an essential part of city and residential life. We walk over them and drive over them every day without thinking a bit about them. In fact, we produce precast concrete manholes every day at Columbia Precast Products. That’s a sign of how ubiquitous they are.

But why are manhole covers round? Let’s find out why the world has decided on circular manholes.

#1: They are unable to fit through smaller openings.

The manhole itself needs to be protected. A round cover cannot fall through the manhole. No matter how you angle it, a round cover can’t be pushed into a manhole. If it were a square cover, there may be a way for it to be inserted diagonally or for someone to drop it in or try to finagle it into the hole.

#2: Ease of use.

Depending on the size of the manhole cover, they can be awkward and heavy to lift. In fact, they can sometimes weigh up to 200 pounds. Because of its round design, rolling the circular cover can make it easier to take off and on.

#3: It requires less material.

It’s true: There is an economical reason that manhole covers are round, too. The more surface area that needs to be covered, the more material is required. So, if there is less material needed to manufacture, the less money it costs.

#4: Circles are stronger.

The perimeter of a manhole only has a small lip and a round cover is the strongest way to ensure it is sealed well. If it were any other shape, it simply would not be able to be held as strongly in place. So the compression of the earth surrounding the manhole is best met with a cylinder.

We’ve been in business for a long time now, and we have the skills, tools, and expertise to help you with your precast concrete project.

That’s right: At Columbia Precast Products, we have the material needed for manholes and more. Contact us today to learn more about our wide variety of products, or visit us today to see how we can help with your urban project.

We look forward to speaking with you!

In the meantime, check out our other blog pages for additional topics.

Round Manhole Covers