Step 1 – Calculate the radius of the curve
Measure the width and depth of the curve; laying straight beams or gutters against the curve in the arrangement shown will help if plan drawings aren’t available.
Apply the following formula to these measurements to calculate the radius of the arc:
Radius = (d / 2) + ((w2)/(8 x d))
Step 2– Calculate the angle of the curve
Mark each end of the curve and measure the length of the arc.
Apply the following formula to calculate the angle of the arc:
Angle = ( l / r) x (180 / π)
Step 3– Calculate the number of brackets
Apply the following formula to calculate the minimum number of RSKR brackets required:
No. of RSKRs = (angle / 4) + 2
The result should be rounded up to the nearest integer.
Step 4– Calculate the gutter lengths
The required length of the gutter segments can be approximately calculated using the following formula:
Gutter length = l / (No. of RSKRs – 1)
Calculations are based on the assumption that the curve has a fixed radius and are for guidance only.