Does Rock Salt Erode Pavers?

You're standing in your driveway at 6 AM, ice everywhere, and you've got that bag of rock salt in your hand. You need to melt this ice, but will you wreck your pavers in the process?

TL;DR: Rock salt can erode pavers over time, but there are safer alternatives and preventative steps that could save you thousands in repairs.

Will Rock Salt Damage Pavers?

Generally speaking, yes, rock salt damages pavers gradually through repeated exposure. We’ve worked with many paver patios and walkways where salt was the main culprit for damage.

Salt seeps into the tiny holes in your pavers, bringing moisture with it. When temperatures drop again (and in Boston, that's every night from November through March), that moisture freezes and expands… over and over again. Each cycle cracks the material from the inside out.

Concrete pavers are especially vulnerable. Natural stone holds up better in some cases, but nothing's immune.

What Kind of Salt is Safe for Pavers?

"Safe" is relative, but some better options include:

• Calcium chloride: Between 0-30ºF, calcium chloride is more effective than magnesium chloride. A study found that calcium chloride melted 42% more ice after 30 minutes than magnesium chloride.

• Magnesium chloride: In general, magnesium chloride causes a slow deterioration for concrete surfaces. It can lead to crumbling and breaking on concrete, and can corrode metal surfaces. That said, most companies pride magnesium chloride on being a more eco-friendly option. 

• Calcium magnesium acetate (CMA): Generally the safest but it’s the most expensive and can be less effective than calcium chloride in extreme cold.

None are perfect, but they're considerably better than straight rock salt.

Is Salt Water Bad for Pavers?

Yes, the residue from salt water sits on your pavers, draws in moisture, and creates a constant wet-dry-freeze cycle.

If you’re near the coast, unfortunately that means you're dealing with double exposure. We’ve seen beautiful North Shore paver installations completely compromised within a few years.

What Ice Melt Won't Damage Pavers?

Nothing is 100% harmless, but better options:

• Sand or kitty litter (this will only help with traction, it won't melt ice)

• Calcium magnesium acetate

• Specialty paver-safe deicers

The key is moderation. Even "safer" products cause problems if you're dumping them every other day.

When Not to Use Rock Salt?

Never use it on:

• New pavers (give them the first winter or two to cure)

• Already damaged or unsealed pavers

• Decorative or high-end installations

• When it's below 15-20°F (it stops working around this temperature)

Does Rock Salt Ruin Your Concrete?

Rock salt causes spalling (surface flaking and pitting). Since most pavers are concrete-based, this is directly relevant to your situation.

Understanding How Salt Affects Masonry Surfaces

Salt lowers the freezing point of water but also draws moisture into your pavers' porous structure. When that moisture refreezes, it expands with enough force to crack stone and crumble concrete.

How Freeze-Thaw Cycles Worsen Salt Damage

As we all know, Boston's winters are brutal. We get 35° one day, 18° the next, back to 40°, then down to 10°. Every temperature swing is another freeze-thaw cycle, and each one compounds the damage. Our crew sees this constantly in commercial properties and historic buildings around Greater Boston.

How Long Does It Take for Salt to Damage Concrete?

Depends on frequency, freeze-thaw cycles, and whether pavers are sealed. Could be one brutal winter or it could be 3-5 years. Either way, prevention is always cheaper than replacement.

Safe Winter Maintenance Tips

• Use deicers sparingly (or skip them when you can just shovel)

• Shovel early and often

• Apply sand for traction instead of melting agents

• Rinse pavers in early spring to remove salt residue

• Work with a masonry team for professional sealing before winter

When to Call a Masonry Professional

Call if you notice:

• Spalling, cracking, or surface flaking

• Pavers haven't been sealed recently

• Historic or high-value installations where DIY risks are too high

At JMS Masonry & Restoration, we handle commercial buildings and historic restorations throughout Greater Boston.

Preventative Sealing and Long-Term Care

Sealing creates a protective barrier against salt and moisture. Reseal every 2-4 years depending on exposure. You can spend a few hundred on sealing now, or several thousand on replacement later.

At JMS Masonry & Restoration, we help property owners keep their masonry in tip-top shape year-round: winter protection, freeze-thaw damage repair, long-term preventative care.

If your building’s pavers are showing wear or you want to protect them before the next freeze or get a brand new walkway this Spring, give us a call. We've been doing this in Boston for decades, and we know what works.