Actually this is true – sort of. Water freezes at 32⁰ and salt lowers the freeze point of water so it will not freeze until a lower temperature. In order for salt to do this it must mix with water to create a “brine” and this is what melts snow and ice.
If you were to throw a handful of salt onto some ice there needs to be an initial source of water to create the salt brine. Of course once the brine is created it begins a cycle of melting the ice which creates more brine and so on until the brine is too diluted to work any longer. So where does this initial source of water come from? Depending on temperature it can come from sunlight melting some ice, traction from car tires melting some ice, or it can be introduced to the salt by a method called pre-wetting. If that isn’t enough science for you let’s talk about temperature. Salt begins losing its ability to lower the freeze point of water at 25⁰ and becomes completely ineffective at 16⁰. This is important information because if the weatherman tells you it is 12⁰ outside salt will not work and if your snow removal contractor is salting your parking lot he is throwing your money down the sewer drain.
Now you have knowledge that quite frankly a lot of snow removal contractors do not have. Now you know how this lack of knowledge costs you money. The good news is that YOU now have the knowledge. Let’s look at an example. Let’s use the 12⁰ scenario. The 4 inches of snow that fell overnight is now plowed off and a residual coating of snow/ice remains. A salt truck is sent out to remedy the problem. The operator applies 1 ton of salt (which you will be billed for at the rate of $280 per ton). After he is finished he notices the lot is still white. This is not normal because usually it would be melting by now (like it does in a 30⁰ storm). What to do? He decides he must not have applied enough salt so he re-applies. Now you are 2 tons in ($560). He moves on and applies salt at some other lots and on his way back to re-load his spreader he passes by your parking lot and notices it is still white. After he re-loads his spreader he informs his boss what he observed and he is instructed to hit it again. At this point it is morning and you have received calls from 2 of your tenants complaining that the lot is still slippery and must not have been salted. The “old you” calls your snow removal contractor and reports this condition and insists that a truck be sent out to salt the lot. The “new you” will explain to the tenants that at 12⁰ they will need to be patient. In the meantime the salt truck has applied a 3rd ton of salt and you are now $840 invested in salt with no results. The fact is that the salt will sit on the ice until the temperatures rise back into the effective range. Both the second and third applications of salt are not needed and are a waste of your money. In fact a sure sign that the salt is being over-applied on your parking lots is that white “haze” of salt residue left over. If you see this after a storm too much salt is being applied to your lot. If you are lucky it will still be there at the start of the next storm and it will act as a form of pre-treatment. Any rain in between will wash it down the sewer drain.
As you can see a little bit of knowledge can create a much better outcome. It allows you to help meet the goal of snow removal operations which should be to achieve and maintain traction as soon as possible in the most cost effective way.
If you find this information valuable there is a lot more to know. General Building Maintenance is offering a free seminar presented to your people at your office. All you need to do is contact us and schedule it! I promise your employees will leave as experts.