The answer is yes, salt does indirectly damage your concrete driveways, patios and sidewalks. Bumps and potholes don't just appear due to regular wear and tear – salt damages concrete over time by causing corrosion to occur under the surface, leading to discolored, cracked and crumbling concrete.
Magnesium chloride is a great choice! While magnesium chloride is more expensive than sodium chloride and calcium chloride, it is less likely to damage your concrete or your lawn. This type of salt only works in temperatures down to 0° F, which is better than sodium chloride but not quite as good as calcium chloride.
Sodium chloride (commonly known as rock salt or table salt) is the safest de-icer for use on concrete.
Ultimately, efflorescence itself isn't dangerous. However, it can lead to potential moisture problems that can cause structural damage to building materials. That means if you find efflorescence in the basement or on concrete and other structures, it's important to take action.
You should NOT use salt on a concrete driveway.
Salt can and will eat away at the surface of your concrete and asphalt.
Rock salt is not only poisonous for your pets and plants but also highly corrosive. Its harmful chlorides cause health risks to children and pets—salt damages concrete driveways, patios, and sidewalks indirectly. Salt corrodes concrete beneath the surface, resulting in discolored, cracked, and crumbling concrete.
In short, efflorescence is rarely indicative of serious structural damage to your foundation. It poses no serious threat to the overall health of your foundation; however, the excess moisture that is causing the efflorescence breakout may be problematic.
Overall, efflorescence is a common phenomenon that is individual with each and every case. It is not harmful but can look unappealing and unattractive. However, over time, efflorescence will gradually disappear.
In many cases, efflorescence will disappear on its own over time (usually after the first year of a paver or retaining wall installation). Efflorescence can also be removed with special cleaners like the Gator Efflorescence Cleaner. On average, you should wait about 60 days before applying an efflorescence cleaner.
You can also use regular table salt, instead of rock salt, for older concrete. If you're feeling adventurous, some recommend using pickle brine or even sugar beet juice to safely melt ice on concrete.
Chemical Attacks
Not even non-porous surfaces are safe. Salts (both sulfates like epsom salt and chlorides like table salt) can react chemically with many minerals found in masonry and cement.
The best time to treat the ground is before snowfall begins. Treating areas before snow (and freezing rain/ice) begins can help prevent ice from forming and prevent snow from settling. Because salt has a lower freezing point than water, it reduces the opportunities for moisture to freeze on treated surfaces.
As with other chloride-based ice melters, over exposure to calcium chloride can harm lawns and other plants if deicer is over-applied or large quantities are directly applied to grass or other vegetation. However, magnesium chloride is considered to be safer for vegetation, plants, people, and pets.
If the damage is a thin layer of salt that can be cleaned off with a broom or a pressure washer then this method will usually work. If the salt has penetrated deeper into the concrete, however, homeowners may have better luck using one of several concrete resurfacing products from their local home improvement store.
Traditional Rock Salt Can Be Damaging to Your Driveway, Walkways, and Lawns. One of the most significant advantages that calcium chloride pellets hold over common rock salt is that they're much less damaging to the concrete and asphalt used your driveways.
Efflorescence and alkali salts can be removed by dry brushing with a stiff bristled brush followed by wet sponging the surface with a mild 5% solution of white vinegar (acetic acid) in water. The whole area should then be wiped down with a damp cloth and allowed to dry thoroughly.
Vinegar and water solution—Efflorescence can be removed by using a dilute solution of household white vinegar and water. A vinegar and water solution is relatively inexpensive, non-toxic, and easy to obtain, mix and apply. Dilution ratio is 20–50% vinegar in water by volume.
Efflorescence itself isn't dangerous or harmful. It can lead to potential moisture problems that can cause structural damage to building materials. So it is important to take action when you notice efflorescence in your basement, on your paving stones, or on other structures.
In general, most efflorescence can be removed by dry-brushing followed by flushing with clean water. If brushing is not satisfactory, it may be necessary to use a very light (brush) sandblasting to remove the deposits.
If your wall started out with only a small amount of water-soluble salts within it, the efflorescence might stay away on its own after one cleaning, or only lightly return. But if you wall has a high salt content, the efflorescence could develop again and again.
Using low alkali Portland cement can help reduce efflorescence. A well-graded aggregate, using a low water-to-concrete ratio, and preventing premature evaporation of water during curing are all good ways to reduce mineral salts. And finally, water sources used in construction should be clean, potable, and salt-free.
Clear all snow from driveways and sidewalks before it turns to ice. Salt should only be used after the snow is removed and only in areas needed for safety.
Driveway salt, sometimes called rock salt, is what you will want. If you want to provide traction and melt the ice, use salt and not just sand. A combination of salt and sand can be used for this, or salt alone. Salting in extremely cold temperatures will not work well, as salt is only effective up to -12 degrees.
Though using sand for snow and ice might be helpful at times, salt is a significantly more effective and efficient solution. The difference between salt and sand is that salt melts ice while using sand to melt ice simply does not work, it just makes surfaces less slippery.