Water turned Ice + Salt + Brick, Stone & Mortar = Broken Masonry

The Pyramids in Egypt and throughout Mesopotamia are phenomenal brick work on a grand scale. Having lasted thousands of years without maintenance, they would be nothing more than a pile of rubble had they been built so long ago in our own home town. These hot arid lands host little threat to these masonry structures. Granted, the sun and sandstorms have played a role in the slow deterioration of these ancient monuments, they have not seen the brutal effects of a St. Louis Winter.

Freeze Thaw cycles are why I have a job. The devastating effects of water and ice are literally powerful enough to carve a Grand Canyon. Inevitably, all masonry structures will succumb to the powerful effects of the ever-changing weather, especially here in St. Louis. This past winter has been the most unusual in my career. Those who reside here in the STL, I’m sure, have heard “If you don’t like the weather in St. Louis, stay a day or two, it’ll change.” Not the case for 2014. It was cold, always. It’s still cold, now, as I write.

Atek Answers

Why Salt is bad for your Brick, Block and Stone Structures.

Understanding the deteriorating process.

We can start by identifying a few things first.

  1. When water freezes and thaws it expands and contracts respectively. If water or any kind of moisture is in your brick block or stone structure, the masonry materials are being pushed out and settling back in with the freeze thaw cycles. 
  2. Rock Salt (NaCl or Sodium Chloride) is a common cure for iced steps, patios, walks and driveways. But dumping salt on your brick, stone or concrete can be as damaging or worse than freeze thaw cycles. Salt is a hygroscopic material. Hygroscopic materials absorb moisture. (For those familiar with the product, this is how Damp-Rid works.)
  3. Masonry materials such as brick, block, stone and concrete are “breathable” materials. They naturally absorb and release air and water. This is normal.

Combining this information, concludes us with…

  • When salt is spread onto an icy masonry surface, the ice melts and salt water enters voids and cracks of the surface such as deteriorated mortar joints in need of tuckpointing or cracked and broken brick. In addition to masonry materials being “breathable”, your brick walk, stone porch or concrete driveway is now loaded with salt and water.
  • When the water evaporates from the area, they salt is still left behind. Being a Hygroscopic material, the residual salt now allows these surfaces to take on more water than before, intensifying the already brutal effects of freeze/thaw cycles.
  • Another negative impact salt takes on brick is efflorescence staining. Efflorescence stains appear as white smears on masonry surfaces.

Safer Alternatives to Salt For Masonry Surfaces

Forgoing the use of rock salt will leave you with a slippery surface, but there are other methods to maintain safety while preserving your masonry steps, walks and driveways. Below are some alternatives to piling the salt on. Listed in order from least damaging to most damaging.

  1. Aggregates like sand or small gravel, even kitty litter can be spread on ice. In addition to absorbing heat from the sun and causing a safe melting process, sand and small gravel will also provide a bit or traction in your steps. The down side would be having to clean up the mess after the ice and snow dissipate. But another plus, you can re-use the material for the next snow. This option is the greenest, most safe way to deal with ice, but can sometimes be less effective and more laborious than the following.
  2. Salt Free Ice melters like Safe-Paw® or Morton® Safe-T-Pet®. Chemical compositions without the use of chlorides make this a great way to be a pet and masonry friendly way of de-icing your paths. The down sides are cost and they don’t provide the same melting power as a salt based melter.
  3. Potassium Chloride (KCl). Still a salt, but poses considerably less damaging effects than it’s more commonly used cousin (Rock Salt/Sodium Chloride). Potassium Chloride blends are also available to reduce costs and provide excellent melting power.
  4. Less Rock Salt (NaCl). If you insist on using rock salt for your ice melting needs, consider using as little as possible and only as needed. Expect rapid deterioration of exposed areas and prepare yourself for repair costs associated with them.

If you’ve found yourself in need of new steps, tuckpointing of your walkway/patio or any masonry repairs due to the brutal effects of winter, give us a call, text or email for a free, no-hassle estimate. Thanks for reading, and have a great day!