So Obvious That It Can Be Overlooked

March 1, 2023
Manholes must be level for asphalt longevity and sustainability

By Aaron Barr, Contributing Writer

Climate change drives extreme weather events, and this has a profound impact on the asphalt that covers 93% of America’s paved roads. Asphalt should last anywhere from 15-20 years. But as the climate warms and creates more severe weather, damage to roads will become more commonplace. It’s imperative that we examine ways to help maintain road integrity.

Utility covers are one of the first places to look. 

The U.S. Environmental Protection Agency (EPA) estimates that there are 20 million manholes in the country, often as close together as 300 feet on any city street.

When cracks and premature road wear develop around utility covers, it’s typically a sign there are problems with the utility cover’s elevation (be it tilted incorrectly, higher or lower than the roadway surface), resulting in cracks, ruts, bumps and crumbled asphalt. 

Consider this: in 2017 alone, 47% of manholes were flooded due to intense rainfall, sometimes leading to sewage spills as well as infrastructure damage.  

Manholes and other utility covers are one area where cities, counties, and other road managers have an opportunity to get ahead of the problem and invest in road sustainability – before a major weather event turns into an emergency road repair operation. 

To deliver modernized infrastructure for manholes, they should have safe and effective drainage systems, and entities in charge of them need proper maintenance plans to prepare for extreme weather events. 

Along with creating a climate action plan and sustainability goals, municipal governments should consider the state of their manholes and other utilities in roadways. They should ask themselves: How are we maintaining our manholes? And how can we install a system to ensure sustainability for the long term?

Replace outdated practices for manhole installation and maintenance 

Practices for installing and leveling utility covers haven’t been significantly updated in the last 75 years. In most construction and repair projects, leveling manhole covers to grade is done manually. Crew members lift heavy cast iron tops with prybars (or by lifting heavy precast concrete tops with equipment) and hold them up as other workers insert bricks, plastic wedges, or wood shims by hand to set the covers relatively close to grade. 

Relatively is the key word here because achieving a high degree of accuracy with this method is difficult, if not impossible. And depending on the material used for shims, they will degrade over time – some obviously quicker than others – leaving a void where water can get in and cause cracks, bumps, and dips to appear in the surrounding asphalt.

These practices are imprecise and can be costly in terms of injuries to crew. They are a weak link – and an opportunity – given the work that must be done now to repair nearly half the roads in the U.S. (the American Society of Civil Engineers reported in its 2021 report card that 43% of our public roadways are in poor or mediocre condition).

We have a lot of work to do as an industry. And, with more extreme weather ahead, we need to be strategic.

Use specified solutions to ensure consistency and safety 

Skillfully laying asphalt around manholes might be relatively straightforward work for a veteran construction crew, but with today’s employment challenges, many people working on roads are inexperienced. A new report by the U.S. Chamber of Commerce finds that 88% of contractors report moderate to high levels of difficulty finding skilled workers. This warrants a new look at current processes and training procedures.

The first step is upgrading engineering specifications to incorporate the latest, safest, and simplest tools for utility cover leveling. Engineered solutions, like bolt- and screw-adjusted manhole rings and precast concrete tops, provide a precise degree of accuracy, enabling even inexperienced crews to create smoother, longer-lasting road and sidewalk surfaces (and safer work sites).

Road crews benefit from having these specs and equipment to ensure they know exactly what is expected for safe and accurate installation of awkward and heavy objects, and roads suffer far less damage from utility covers that aren’t level to grade.

Cast iron rings and precast tops are premade with the capability to use specially engineered screws that can be turned from above with a single ratchet or screw gun. This allows the tops to be quickly leveled exactly to specification by one or two workers without the use of machinery, prybars, or shims. In addition, the screws are uniform in size and easy to carry in a pocket, so road crews don’t need to carry around buckets of different sized shims. 

Add manhole maintenance to your strategic plan

Given that imprecisely leveled manhole covers directly affects the longevity of our roads, why is manhole-leveling such an afterthought in the road construction process? Manhole leveling tends to be the last step in the paving process and is often in the back of a foreman’s mind in terms of priority.

Rushing to get the job done, particularly in an emergency, when relying on less experienced crews and outmoded manual methods, all influence job quality.

A well-run county or municipality will have a clearly laid out plan to replace and maintain roads. However, many do not have plans or specifications in place for how manholes should be maintained and repaired. This can be a costly oversight because when a poorly leveled utility causes bumps and cracks and water damage due to wear and weather, it’s often outside any warranty from the paving company (typically two years).

Then the costly road repairs are on the county or municipality’s dime. And even when it’s under warranty, if specs are in place and they are not followed, a municipality has a much stronger case to make for having the paving contractor make the needed repairs.

Looking to the future

Global Positioning System (GPS) satellites and lasers allow much greater precision when laying asphalt. The use of GPS is common on job sites today, but new advanced systems that use intelligent compaction technology help operators identify where they’ve made a pass in order to have consistently laid asphalt. With more precise tools to lay asphalt, it’s even more imperative to have engineered solutions for leveling manholes to precise grade – something that’s impossible when workers are winging it with prybars and shims.

Manholes may forever dot our city landscapes, but that doesn’t have to mean constant maintenance. By leveling manholes correctly the first time, municipalities are making a strategic investment in sustainability of roads for many years to come. R&B

Aaron Barr is the CEO of RimRiser

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