Successfully maneuvering a large, heavy paver through tight turns, such as those required for parking-lot islands or cul-de-sacs, requires a skilled operator working under ideal jobsite conditions. Before tackling a tight-radius job, assess the capabilities of the paver and the geometry of the jobsite. To make tight turns, the machine usually needs to be equipped with an offset paving mold and have a low center of gravity.
One of the most important requirements for successful curb placement is proper subgrade preparation. Be sure to remove excess subgrade using grading equipment so that the paver can move freely around the turn. Proper installation of the stringline is critical because it controls paver steering and elevation sensors, thus determining final line and grade of the curb. Accurate stringline placement is needed to meet specified tolerances. Radius wheels are typically used to guide string-line placement for outside radius turns of 7 feet or less, which are often required when placing curbs for parking-lot islands. To choose the proper size radius wheel, the sum of the wheel radius and the paver offset should equal the distance from the radius point to the back of the curb.