Safely De-icing Natural Stone, Pavers, and Concrete

If you live in the Nashville area, you know that we never know when we’ll have icy roads and walkways, but it does happen and often enough that it’s a good idea to be prepared.

If you’re in a more northern climate, chances are even higher for you!

Keeping your home, your family, and your visitors safe is a top priority when winter comes around and part of that is ensuring that driveways, walkways, sidewalks, porches, and patios are free from ice.

Ice in these areas presents a serious slip and fall hazard. Thankfully, there are several ways to reduce the risk of accidents on iced over surfaces.

Most people immediately think of rock salt for de-icing – with good reason. It is definitely effective. Unfortunately, it is damaging to natural stone, pavers, and concrete.

Let’s look at some ways to de-ice natural stone or concrete without causing damage

Salt is for Food, Not Stones

Salt is a tough substance to work with. It can cause a lot of damage, but it can also be used to melt ice and snow. If you want to de-ice your stone walkway or patio, salt is not the best option, as it will harm the material over time. Salt works by lowering the freezing point of water, thus melting ice and snow. 

When using salt on any type of natural stone material, such as travertine or limestone (both are actually types of limestone), there are several ways that this could affect its appearance:

• Flaking – Salt can cause flakes in these materials which will then easily break off; this makes them more susceptible to future damage from weather conditions such as rain or wind erosion.* 
• Corrosion – If left untreated after using salt solutions repeatedly over time; corrosion may occur where chemicals have been absorbed into porous surfaces, causing them to deteriorate.* 
• Bleaching – Exposure to high concentrations of sodium chloride (salt) damages colored pigments within these rocks, resulting in bleaching effects like white spots appearing where once there were colors present before applying too much sodium chloride solutions during winter.

Skip the Rock Salt – Then What? 

The best way to keep your natural stone and concrete safe is to prevent ice from forming in the first place. This is far easier said than done. There are some tips that can help with this:

• Keep up with the shoveling – ice forms after snow builds up. If you can keep these places clear of snow, you may stay ahead of the ice.
• Put down a layer of fine sand or biodegradable kitty litter before it snows. This makes it harder for the ice to adhere to the surface (and then break off when someone steps on it).
• These also are excellent for providing traction on icy surfaces. Other traction materials include gravel, wood chips, and straw.

Alternatives to Rock Salt 

If you’re worried about the effects of rock salt on your stone and concrete, there are alternatives available. Some are better than others, some safer for pets or the environment. Below is a list of commercially available de-icers and their pros and cons:

• Magnesium chloride (MC) – this is perhaps the safest option for pet owners* because it contains no toxic substances. It can also be used as a fertilizer, so it has many benefits beyond de-icing that you might have not considered before. Because MC does not melt ice as effectively as rock salt does, though, its use should be limited to areas where nothing will be damaged if they get wet after a storm/snowfall (i.e., patios). 
  • *It is considered safe for pets in general, however, it can be fatal for a pet with kidney disease. 
• Calcium Magnesium Acetate (CMA) – this compound has been known to cause damage when used on concrete surfaces, yet it is often used successfully on pavers and other natural stones, such as marble and granite due to the fact that those materials tend to have higher porosity levels than concrete does (which provides enough space for moisture evaporation).
• Potassium chloride – this is often used as a de-icing agent because it melts snow and ice at lower temperatures than rock salt does. It is also less corrosive than other salts and doesn’t leave behind the residue that can cause damage to concrete surfaces. Like magnesium chloride, potassium chloride is considered safe for pets, except for those with kidney disease.
• Calcium chloride – this is often used in conjunction with magnesium chloride because it has a lower melting point than magnesium chloride, which allows it to be effective at colder temperatures. Calcium chloride can also be used as a de-icer on its own in warmer weather because it doesn’t leave behind a residue like other compounds do.

What About Homemade De-Icers?

You’ll see a lot about homemade de-icers on the internet. Many are isopropyl alcohol based. Isopropyl alcohol has a freezing point of -97º so even when mixed with water, it can melt ice. Here’s a common “recipe:”

• 3 parts water to 1 part rubbing alcohol
• Mix them together and apply with a spray bottle or some other method (if using an applicator). Be sure to sweep or shovel away excess water or you’ll have new ice to contend with.

Since we’re on the topic, it has been reported that the alcohol solution can also be used for de-icing car windows. Just put it in a spray bottle and spray your icy car windows.

Vinegar based homemade de-icers – 50/50 vinegar and water will break up sheets of ice; be sure to clear the water when finished.

Sugar Beet Juice – completely safe & effective, but watch for staining! 

Fertilizers that include ammonium sulfate, potassium chloride, or urea are slower than rock salt but less damaging.

Other options? 

Electric snow melting mats are heating pads for your porch, driveway, and walkways. Cost varies greatly, as does effectiveness, we assume but have not tested. They can be purchased for as little as $100 to over $2,000.

Conclusion

While de-icing is a necessary part of winter, it can be done in a way that preserves the look and feel of your natural stone. The key is to make sure you take the proper precautions when working with these materials to avoid damaging them or compromising their looks. The good news is that it’s possible when you know what to avoid and what to consider. We hope this article has given you the information you need to care for your concrete and natural stone while keeping your walkways safe.

As always, if you have landscape design needs in the Nashville area, contact us for an estimate. Our work has been featured on HGTV and can be seen throughout the area. Be sure to check out our website portfolio for examples of past work.