Gritting and roads
Salt and how it works
Find out how salt works and where you can collect it.
We use rock salt, which looks like light brown gravel, to treat roads and paths.
The salt works by reducing the temperature at which water freezes so it can prevent ice forming on the road surface.
Once it is spread on the road or footway surface it needs traffic on it to help in freezing conditions, and is effective at temperatures as low as -7 degrees centigrade. It is less effective down to -10 degrees, after which it does not work.
On a dry road, salt can be effective for a considerable time and we may not need to retreat the road even if there is a light frost.
Even if a road has been treated with salt, it can still freeze. For example, if it rains after we have salted the road, the water can wash the salt off.
Salt will not stop snow lying on roads, unless it is very light. So when it snows, we need to use snow ploughs to clear the snow then treat the road with salt. In very heavy snow conditions, we may add coarse materials, such as sand, to the salt to give traction for vehicles wheels and to help break up snow layers.
Residents can pick up small quantities of salt using their own container to treat their local streets from local grit bins or our recycling centres.
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