Fiberglass manholes are handy devices that work well if you need to set up a flume or weir box that’s underground. Not all flow channels are exposed to the open air, but when they are underground, you’ll need an easy way to access them for maintenance and flow rate measurement. That’s where fiberglass manholes come in. It’s important to remember, however, that these manholes can be outfitted with a variety of different tops. Here’s everything you need to know about choosing fiberglass manhole tops.
Manhole Top Styles
Domed Tops
Domed tops are among the most common kinds of tops available, and that’s no accident. The reinforced design makes it sturdy and able to resist the elements, all while offering plenty of room for workers to enter. In fact, it uses a piano hinge with fully opening action, making it the easiest to enter and exit compared to all other types of manhole tops.
These tops are quite convenient as well. For example, a domed top is situated on the top edge of the manhole itself, so the seal between the top and the barrel of the manhole doesn’t have to be watertight. If standing water is common at the manhole’s location, however, the top of the manhole may be set a bit higher than usual when using a domed top.
Aluminum Hatch
An aluminum hatch top has a key advantage that any domed top design simply can’t offer. Aluminum hatches are flat and blend well with most sidewalk designs. This is the top you’ll want to go with if you’re looking to install a fiberglass manhole in an area that gets a lot of foot traffic, like a sidewalk, since they don’t stick out like a domed top would and aren’t a trip hazard.
Merely opting for an aluminum hatch isn’t enough to eliminate the risk of a trip hazard. You’ll have to work to make sure the hatch is flush with the top of the manhole itself. Even the most minor calculation error can create a trip hazard that’s especially dangerous since so many people view aluminum hatches as seamlessly integrated with the surrounding foot traffic area without even thinking about it.
Highway Loading
The only time you’ll need to opt for a highway loading top to your manhole is when it’s situated in an area that gets a lot of vehicle traffic. These tops are incredibly strong, able to resist force and pressure from heavy vehicles. Additionally, they tend to be a bit easier to make flush with the surrounding environment.
It’s important to remember that with highway loading tops, some errors are far easier to fix than others. For example, if your manhole is a bit too short, you can just add grade rings until it’s at the necessary height. If your manhole is too tall, however, that’s going to require some intense modifications, some of which may not be even possible to do in the field. Either way, it’s quite costly.
Manholes from Tracom
When you’re looking to get a manhole of your own, Tracom has got you covered. Our team makes choosing fiberglass manhole tops easy based on what you’ll need your manhole for. Contact us today to learn more!
