Hail

Like snow, hail can cause blockage and subsequent leakage. For this reason, sumps and rainwater heads should have leaf guards that are the same size as the sump, provide a large free overflow area and should not be tapered, because of the wedging action of hail.

Snow gutter boards should be provided for all internal gutters, as a baffle, to allow hail melt water to drain safely without overflowing the gutter.

In all areas prone to hail—spouting, gutters, and their supports—should have additional fixings. See Gutter Support Systems.