Curved walls can be formed in four general ways, using fixed-radius manufactured walers, fixed-radius job-built walers, adjustable walers, or modular form panels.
FIXED-RADIUS MANUFACTURED WALERS
Fixed-radius walers are made to a true curve, but they're not adjustable. For each radius desired, you need a different waler. With fixed-radius walers, you don't need to construct a curved jig or template to set the form to the desired radius. The precurved walers set the curve of the form, instead. Because the walers are made to a true curve, not a series of chords, the final form and the finished wall are true curves.
FIXED-RADIUS JOB-BUILT WALERS
On the job, you can make curved walers by cutting boards to the desired radius. Or you can use straight aluminum beams and nail boards cut to the proper radius to the nailer strips inside the beams.
ADJUSTABLE RADIUS WALERS
With adjustable radius walers, the same forms can be used for walls of different radii. However, each type of adjustable waler has its own range of adjustment, usually from a certain minimum radius up to a straight wall. Several types are available.
MODULAR FORM PANELS
Several form manufacturers make modular form panels for forming straight walls. Set on chords of a circle, these rectangular form panels also can form curved walls. The panels are supported with braces or curved walers, and narrow fillers are added when necessary to complete the circle.