Identify the outdoor areas used by pedestrians which are most likely to be affected by ice, eg building entrances, car parks, pedestrian walkways, shortcuts, sloped areas and areas constantly in the shade or wet. Rock salt (plain and treated) is the most commonly used ‘grit’. It is the substance used on public roads by the Highways Agency and is available form builders’ merchants. Salt can stop ice forming and cause existing ice or snow to melt. It is most effective when it is ground down, but this will take far longer on pedestrian areas than on roads.
Gritting should be carried out when frost, ice or snow is forecast or when walkways are likely to be damp or wet and the floor temperatures are at, or below, freezing. The best times are early in evening before the frost settles and/or early in the morning before employees arrive. Salt doesn’t work instantly; it needs sufficient time to dissolve into the moisture on the floor.
If you grit when it is raining heavily, the salt will be washed away, causing a problem if the rain then turns to snow. Compacted snow, which turns to ice, is difficult to treat effectively with grit. Be aware that ‘dawn frost’ can occur on dry surfaces, when early morning dew forms and freezes on impact with the cold surface. It can be difficult to predict when or where this condition will occur.
Dry surfaces, when early morning dew forms and freezes on impact with the cold surface. It can be difficult to predict when or where this condition will occur.