Western Michigan contractor gets a flexible, durable solution with adjustable manhole riser

April 14, 2016
A completed riser project in Grand Rapids, Mich.

Founded in 1916, Rieth Riley Construction is a large paving firm, serving Indiana and Michigan with 30 asphalt plants. With that kind of paving volume, and a nearly century-long history, the firm has rigorously tested hundreds of infrastructure solutions, and the tools and techniques that make the cut are likely to be best of class when it comes to paving.

One such solution, in use at Rieth Riley for nearly 20 years, is the American Highway Products Pivoted Turnbuckle Manhole Riser—the firm has been ordering and installing them since 1996. “Just in our region, we use 200-500 annually,” says area manager Kirk Breukink. “And company-wide, of course, we use a lot more than that.”

Breukink’s area includes western Michigan’s Kent County, home to Grand Rapids and the Gerald R. Ford International Airport, and sometimes described as Michigan’s economic and manufacturing center. “We mainly use the risers in Kent County, because their specifications require it,” he explained. “And frankly, we use them whenever we have the option because they’re so convenient. But there are still some areas where we’re required to adjust utilities with grade rings or cast-iron risers.”

Breukink estimates that the material and labor cost of raising a manhole with adjustable risers totals less than $150. By contrast, adjustment with concrete grade rings costs at least $200 per manhole, and up to $500, depending on circumstances. And just as importantly, in his view, is the extra time required for raising rims with grade rings. “It can easily add a day to a project,” he said, adding that with risers quality is not an issue. “We’ve been raising utility rims to grade for a long time. And in all that time we’ve never noticed any difference in performance between adjustable risers and other methods—we’ve certainly never had a riser fail.”

A durable, convenient, cost-effective solution

American Highway Products Pivoted Turnbuckle Manhole Risers are flexible rings made of sturdy galvanized steel. Because they’re lightweight, custom-sized and flexible, they can be inserted easily into original manhole rims, usually by a one-man crew. A Phillips-head screwdriver is then used as a lever to crank the turnbuckle. The mechanical advantage afforded by the expansive turnbuckle is enough to exert thousands of lb of force with just a few cranks, and that’s more than enough to seat the new riser in the old rim tightly, securely, and permanently. The old manhole lid is then placed in the riser at the correct grade, matching the road profile so that there are no exposed pavement edges, which prevents premature cracking or crumbling.

Breukink is also asked to use cast-iron risers on occasion, again due to agency requirements. He doesn’t look forward to it. “Cast-iron risers are getting hard to find, for one thing,” he explained. “So they’re hard to get in less than a week, even from the foundries that make the manholes. And they’re heavier and harder to install, so we use a two-man crew instead of a one-man crew. And also, we feel that the adjustable steel risers are safer, mainly because they’re lighter, which means reduced exposure to strains, sprains and soft tissue injuries—our safety department loves that.”

The risers are installed just before paving. “We can install 20 per hour if we need to, so it’s convenient to have a crew moving ahead of the paver,” Breukink said. “It’s a very simple installation process, and takes ten minutes or less per manhole.” Sometimes, if manholes are exposed for a few days between milling and paving, Rieth Riley will use another American Highway Products product, Manhole Safety Ramps, to guard against vehicle damage. The safety ramps are tapered rubber rings that slide over exposed manholes for convenient temporary protection.

Breukink says that only two or three different manhole sizes are common in his region, and he tends to keep risers of that diameter in stock, in different thicknesses as needed to match paving lifts. If custom sizes are required, he is usually able to get them from the supplier, “within a week, or in just a few days if it’s a rush order.”

The risers are usually used on new paving projects, but they’ve been used on repairs as well. “They really saved the day for us on a highway project that saw some settling in late October, when our paving season was closing down,” Breukink explained. “There had been some tire rim damage, so we had to do something. We were given a six-hour window to close the lane and do our work, and we were able to get the risers on the five affected manholes in that time, and patch around them. They held over winter, until we could get back to the project.”

Tested over time by contractors and municipalities in all conditions, American Highway Products adjustable risers are a flexible solution appropriate for use on virtually all paving projects that require utility adjustment.

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