Manhole riser prevents infiltration and improves public safety
Problem: The St. Louis Water department raised manholes to grade by manually exposing and lifting concrete grade rings, a process that takes several hours and compromises new paving lifts. After jackhammering and raising, the newly raised rims have to be sealed in with new concrete, creating seams in the new pavement that wear faster than undamaged concrete. It was clearly a problem, so it made sense to do a pilot test with an adjustable riser.
Solution: The American Highway Products riser relies on a pivoted turnbuckle that can be expanded with a screwdriver. The screwdriver, used as
