Ice Melt vs. Rock Salt - What’s the Difference?

There’s a bewildering array of choices for ice melt, ranging from rock salt to blends with additives designed to jump up performance. What’s the best choice?
#snowmelt #icemelt #icemelting
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The winter is coming and for areas that enjoy snowfall, that means controlling snow and ice deposits outside your door, on sidewalks, and in your driveway. Snowblowers and snow shovels are mainstays in your snow management arsenal, but good snow and ice melt can make a difference in how manageable snow and ice are.
First, a bit of chemistry. Salty water freezes at lower temps than fresh water does. That’s why you won’t see seawater frozen as often as fresh water. So, if you can create a saltwater layer (brine) when applying salt or ice melt to a surface, your control of the ice or snow can be effective.
When it comes to snow and ice control, brine is the key factor and that affects everything else.
Creating a brine layer is easier the closer the temperature is to 0° Celsius/ 32° Fahrenheit. Even a moderate application of ice melt/salt, with a light snow or ice covering, will have an almost immediate effect on brine formation and melting happening right away.
Brine formation is best accomplished BEFORE snowfall by applying the product to areas where you want to control snow or ice buildup. The second best time is when there is only a light layer of snow.
But what if it is extremely cold, ice has formed, or there is snow already in place? If you are using plain old rock salt, you’ll need to remove the snow and apply salt scattered across the surface as evenly as possible.
If the temps are so low that ice still forms, you’ll need to consider using ice melt products with additives that boost performance. Magnesium Chloride is one such additive. This will lower the freezing point of the brine even further. This chemical is very effective as a pre-treatment and is used by many cold-weather municipalities to treat freeways in advance of a snowstorm. It greatly reduces the bond between snow and ice and the road surface and allows for efficient snowplow operation.
Calcium Chloride is the next step up. When this compound mixes with water, it produces heat. This is called an exothermic reaction, and the heat is real! In very low temps, this allows enough brine to form to break the bond between the ice and surface. When you buy an ice melt product with calcium chloride, is one of the ingredients, but not the entire product. It is mixed with sodium chloride.
Granule size also differentiates between regular rock salt and ice melt products. If the granules are too big, then brine formation is very slow. If too small, the compound melts almost immediately and has very little staying power. The size needs to be just right to allow brine formation but to “slow-release” it.
Another important consideration is the amount of product it takes to get the job done. If you need to apply a lot of salt, and there are flower beds or turf adjacent to the slab, driveway or sidewalk, you risk sterilizing the soil or at least greatly diminishing the ability for plants to grow well. Using ice melt products, at their recommended application rate, means less salt (sodium chloride) will be in the soil, with less effect.
Snow and ice melt products also typically have a colorant added to them that is safe for pets, and won’t stain concrete. This helps you to not over-apply the product as it’s easier to see where it has already been applied. It’s hard to see a white product on white snow or ice!
Also, NEVER apply rock salt or snow-melt products to concrete surfaces that are less than one year old. They haven’t properly cured enough to resist spalling, and surface damage will occur when melt product has been applied and very low temps are reached.
JUST DO IT YOURSELF!
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[@rodneycaupp5962]

Very nicely done. No rock Salt left unturned; I like this guy. I got the exact info I hoped for, concerning Plant toxicity, and advantages to added Magnesium Salt -Ice Melt. Thee 40 # bag of Rescue Sodium pellets sits in the back of the little Mustang, to help with traction. The SUV, Drives over top the snow, with its excellent rear wheel drive and slide control. CAN YOU MAKE IT SNOW HARDER GOD ? We need the spring melt...

[@wolfeadventures]

Perfect timing. Thank you for addressing the concrete damage aspect.

[@DirtFarmerJay]

You're welcome!

[@JohnSmith-gz3eg]

On the coast of NC and waiting for the bitter cold and ice. Thank you for this kind sir!

[@DirtFarmerJay]

My pleasure!

[@HandsIntoHistory]

Found an 'Easter egg' while watching this video-- caught sight of your camera person in the window, lol 😆 Thanks Jay for great information, as always!

[@DirtFarmerJay]

Love it. That's Rob, our friend and business partner. Thanks for writing!

[@jacquilewis4663]

Best explanation for steep drives and what to apply - 'create a brine'! Thanks.

[@DirtFarmerJay]

You bet!

[@boromoose]

Thanks for this informative video. I just had a new concrete driveway installed in October and knew not to use salt on it, but thought it would be OK to use other ice melts on it. Now I know not to use anything on it, other than maybe some sand for traction if I can’t get it clean enough with my snowblower.

[@DirtFarmerJay]

You're welcome. Next year, you'll be ready to go. Best, DFJ

[@slimwantedman6694]

Good morning from Southeast South Dakota

[@DirtFarmerJay]

Morning!

[@LeahYYC]

Great video however, how do you make the ‘bribe’ you’re talking about with the magnesium one. I live in 🇨🇦 have a high traffic corner sidewalk lot that gets no sun due to N facing & fence so by the time I get home, I shovel the show but left with a hard packed 1” ice under. Would the ‘brine’ you speak of work for that? Keep in mind our winter temps are usually 10f to -57f. I would really appreciate your advice & thank you in advance. Leah ❤️

[@preethoo5]

*_Can you do a review of heating mats for the driveway?_*

[@AngieUploaded]

Southern here and moved up north. Trying to figure out the best for driveway, before winter storm hits. The melts we bought say to remove the slush to prevent refreeze. Wouldn’t that make it worse? What’s the best as a preventative?😊

[@DirtFarmerJay]

The idea is to get a barrier between the surface and falling snow or build up. So, preventative coating takes car of the a moderate first snow fall and allow it to be moved of. Each time you can start with with a clear surface, the better. The slush will eventually get enough water content in it that the snow melt is at a low concentration and can't keep the ice melted. No ice melt will take care of heavy snow falls, it's a tool to reduce work and allow walking surfaces to be kept clearer longer. I hope that helps. Best, DFJ

[@crazysquirrel9425]

calcium chloride = prestone driveway heat. I have mixed a little calcium chloride in with rock salt as a booster. Calcium chloride is best used for ice treatment. I bought water softener salt (large pieces too). Put that down on the road by my house early. Traffic will break it up to much smaller pieces. Longer lasting but slower to work. Best way to use salt and similar is to wait till the snow/ice turns into slush, then shovel it way, not allowing it to dry on the surface. Less damage to driveways and sidewalks that way.

[@DirtFarmerJay]

Good insights, Crazysquirrel!

[@crazysquirrel9425]

@@DirtFarmerJay Thanks! Lernt from skool of hard knox ya kno! lol Interesting thing about Calcium Chloride is that it melts little holes in the ice surface then melts underneath the ice. At least it is easier to break up and remove the ice. Wish I could still get Ammonium Nitrate. Worked great and runoff was fertilizer for the lawn. Need a license now to buy it.... And paperwork...

[@ROJO25]

Over time ice melts destroy concrete regardless its age. Moreover, marble and/or wood flooring etc.. can be damaged by these caustic chemicals when inadvertently tracked inside on shoes. I don't use any of these products for those reasons. It will ultimately be an expensive fix for a temporary problem. Snowblowing works well for me, the snow and ice typically clears out within 24 hours after using a two stage machine. The single stage machines with rubber paddles clear closer to the ground delivering even faster clearing times.

[@DirtFarmerJay]

Thanks for weighing in and sharing your insights! Best, DFJ

[@Andrew-pv8oz]

What about asphalt?

[@beltycat5490]

Is any product 100% safe on concrete?

[@DirtFarmerJay]

To much of any product is not a good think. The least amount to do the job is the best way to approach this.

[@MsSkipperkim]

Not just the mountain west using eco melt. I live in eastern Kansas. We had an ice storm followed by a foot of snow.

[@DirtFarmerJay]

Thanks for sharing your experience with eco melt!

[@rancid216]

All I use is Prestone Driveway Heat that is calcium chloride. Throw it on an icy sidewalk and it eats up the ice.

[@DirtFarmerJay]

Yep, calcium chloride creates actual heat, so it cuts the ice to get a brine going under the ice sheet. Thanks for writing and sharing! Best, DFJ

[@superdog1964]

It is also eating up your cash. In most areas, calcium chloride is available in 40 or 50lb bags that cost 1/3 the price at your local hardware store. Let Prestone and it's marketing team handle your car's radiator and you deal with your sidewalk and wallet Lol.

[@rancid216]

I have a row home with no basement or attic, so I don't have room for 50 pound bags. I just buy 4 or 5 of the 9 pound Prestone jugs each year.@@superdog1964

[@WhoOwl-o4f]

@@superdog1964I bought one of those products from the car section because Walmart was all out of the forty pound bags, worst hole in my pocket I ever made, but at the time I needed it, I went through most of the product just salting my walk way

[@jaycawthon3463]

One option is to use the lawn or garden fertilizer that you may have left over. I think it needs to be chemical not organic. Organic might give you some traction but not melt the ice.

[@DirtFarmerJay]

Yes, I've done that before with light snow. I used up some grass fertilizer, ammonium sulfate. It worked moderately well. Thanks for watching and writing! We appreciate it. Best, DFJ

[@Mrs0114]

Which is best for wooden patios??

[@DirtFarmerJay]

I think ice melt with either magnesium or calcium chloride additives would be the best choice as it would get the ice film off your deck faster with a smaller amount of product compared to using regular salt granules. I hope this helps! Best, DFJ

[@mpgisbtsarmybaefighting2838]

Good question. Thanks for asking as I was wondering about that. Take care.

[@gordonmoen6038]

How about for melting ice on aluminum patio roof systems

[@DirtFarmerJay]

You need a magnesium chloride melt, not sodium or calcium chloride. They are highly corrosive to aluminum. When temps allow, any ice melt residue should be rinsed off thoroughly. Best, DFJ

[@ccdogpark]

I bought a squeegee for this purpose. The first thing I do after heavy snow is clear off our aluminum awning that protects the side door from the elements. I'm 74 YO and need to climb a ladder to do this, but I don't want the weight of snow or ice to undermine this piece that would be annoying to replace.

[@markd9105]

Amazon left a 40lb box or cat litter on my door by mistake I was wondering if it could be used on ice. It's free what the hell lol.

[@DirtFarmerJay]

It'll give you some grip, but no melt. It's clay-based, so it will tend to become sticky and be tracked into your home. Heads up! Best, DFJ

[@marjoriebiedron740]

What about pet friendly?

[@DirtFarmerJay]

All salt based ice and snow treatments (which almost all are), carry some inherent risk, depending on your pet's preference for the taste of salt. Since you use less with the ice melt products, there is less for pets to have access to. However, when pets walk in treated areas repeatedly, they will get more exposure. The typical response is for the pet to lick their paws, which can lead to ingestion. In products like what we featured, magnesium chloride is not the major ingredient, but it is there. There is a lot of strong opinions on the safety for pets, but an overlying principle seems to be to keep doses of the brine to a minimum, if there is concern, you can rinse your pet's paws. Also, in the products we used as samples (from Brody Chemical), the colorant used is food grade, but it can be tracked into your home, so some people prefer a poduct like EcoMelt, which doesn't have colorant. Best, DFJ

[@boromoose]

I use Morton Pet Care Ice Melt. It says it melts down to 10 degrees Fahrenheit and is salt and chloride free. Ingredient list is Urea CAS #57-13-6. Says it is “safer for pets, people, plants & surfaces *. The asterisk directs you to the back panel for details, which includes that it was developed with veterinarians, and that you shouldn’t use it on poor quality concrete, and concrete less than a year old.

[@SledDog5678]

The calcium Chloride? WHAT ABOUT ANIMALS THAT WALK ON IT??????

[@DirtFarmerJay]

Yes, indeed. That is a topic we covered in the episode. Calcium chloride is not the best choice when pets are involved. They can track it and it can cause burns or irritation to their paws. In that case, a magnesium chloride product is the best choice and we featured a few in the episode. Best, DFJ