Winter Rock Salt: Your Questions Answered
In a recent edition of the Greengates Builders Merchants blog, we introduced our range of rock salt, which is an especially useful product during the cold temperatures and related ice and snow that occur during the frigid winter months here in the UK. For this article, we're going to answer some of the most frequently asked questions about rock salt.
What is rock salt?
Rock salt is a halite, which is the basic mineral form of sodium chloride. It is mined in vast quantities and has many uses. The massive mined slabs are crushed into smaller pieces, which are collectively referred to as 'rock salt'.
Is it the same as table salt?
Broadly speaking, the answer is yes though you certainly wouldn't want to sprinkle it on to your fish and chips! Table salt goes through numerous processes that purify it to make it fit for human consumption. Rock salt that is going to be used for de-icing purposes is not subject to such purification processes so cannot be safely eaten.
How does rock salt work?
The product works thanks to a process known to science as 'freezing point depression' . In the presence of liquid water (the freezing point of which is widely known to be 0°C), the component ions within rock salt begin to break apart. These additional particles interfere with the ability of the water to freeze, preventing crystals from forming. The net result is that the water's freezing point drops down to as low as -10°C, enabling it to remain liquid instead of forming into dangerous ice.
When should rock salt be used?
Rock salt works best when it is used in a preventative way. It's always a good idea to keep a close eye on the weather forecast and, when temperatures of freezing or below are predicted, to treat any outdoor surface that might be affected by snow or ice. It can be used to treat surfaces that are already covered by snow and ice though may take some time to work.
Are businesses responsible for salting surfaces?
While there is no specific legal obligation for a business to apply winter salt, they must comply with the Occupiers' Liability Act of 1957. This legislation obliges businesses to ensure the safety of its customers by taking 'reasonable care'. If a customer is injured by slipping and can show that the business did not take such care, a compensation claim could be successfully filed.
What is the effective coverage rate of rock salt?
It all depends on how you are using the salt and what the weather conditions at the time. When using the product to prevent the formation of snow and ice, between 10 and 20 grams per m² is sufficient but this should be increased to 30 grams per m² if conditions are severe. If used on snow and ice that has already formed, between 20 and 40 grams per m² should be used depending on severity.
What is the difference between brown and white rock salts?
Brown rock salt is less expensive but can cause marking and staining to internal surfaces and so it is mainly used for industrial and municipal applications. White rock salt, which is more purified and has less mineral contamination, is suitable where aesthetics are of concern, such as in domestic and commercial environments.
Greengates offer brown and white rock salt in bags of medium or bulk size. Please browse our website for further details and get in touch with our expert team if you have any further questions.