What Do We Use For Winter Gritting?
What is used on roads to melt ice? Rock salt is the common material used in treating road surfaces before freezing. It’s mined from underground mines. In some instances, it’s used along with grit with the aim of providing traction and grinding up the salt. Rock salt is brown in colour since it’s unrefined and has impurities, and is usually called grit.
How does gritting work?
Rock salt, the material used to melt ice, works by lowering the road moisture’s freezing point. This stops ice from forming and causes the snow or ice already present to melt. However, for grit to produce the best results, it needs regular traffic to crush it and spread across the entire road. If it happens to snow heavily during the night, the snow will still settle on a gritted road. The first drivers on the road will unfortunately experience a slippery road.
Does grit keep?
If kept covered and without exposure to the rain, grit keeps for a long period of time. Councils keep it in barns or under a waterproof sheet to shield it. When kept in these conditions, stockpiles will keep for several years at least or much longer.
However, we never get to know how long since councils will use them and replace the stocks with time. If the stock is exposed to water, the pure salt will dissolve in water and will leave a high percentage of the impurities, which are orange-brown in colour. It will become less effective when it comes to thawing ice.
Why do councils grit the same stretch of road repeatedly?
They normally do this when there is an extended period of snowfall. The sludge, a result of past gritting and high traffic flow, will start to wash away the previous grit and risks freezing the road surface. Salt can also be washed away by rain.
Before the sub-zero night, gritting should be done after the rain but before freezing occurs. Grit that’s spread on the ice needs to be worked on by moving traffic to enable it to thaw. It’s often an extremely small window of opportunity that can be missed, and in some instances, an unexpected downpour may occur after the road has been treated. If the need arises, the local council will re-run the area.
Can it get too cold for grit to work?
Yes. Salt can only work at temperatures above -8 to -10 degrees Celcius. Below this temperature, salted roads will still experience freezing.
Do councils put grit on the roads as well as rock salt?
Stone grit is only used in most instances on hard packed ice and snow. In situations where the snow has settled already, salt can be mixed with grit to offer traction and help in breaking down frozen surfaces.
Winter Gritting Peterhead
For local gritting services contact our road gritting contractors. We work on private roads, carparks and entrances to offer winter gritting. Contact us today for gritting from Dundee to Aberdeen to Peterhead.