Quick Answer
Concrete spalls when de-icing salt meets freeze-thaw cycling on non-air-entrained or unsealed surfaces, especially during the first winter after pouring.
Spalling is a surface failure, and it is largely preventable. B.G. Concrete pours air-entrained exterior mixes and gives written care steps because the first winter is when a new slab is most vulnerable in the Chicago suburbs.
How salt and freeze-thaw cause concrete spalling
De-icing salt drives extra water into the surface, which then freezes and expands, popping off thin flakes of concrete. On non-air-entrained or unsealed slabs this freeze-thaw scaling is the most common cause of a pitted surface.
Why the first winter matters most
r/Concrete contractors repeatedly tell homeowners to keep salt off new concrete the first winter, because concrete that has not fully cured and sealed has little defense. Sand provides traction without the chemical attack during that period.
How to prevent concrete spalling in Chicago
Air-entrained concrete builds in microscopic air pockets that absorb freezing pressure, and a quality sealer reapplied periodically keeps water and salt out. Proper finishing and cure timing round out the defenses against spalling.
Related Questions
Can I use salt on new concrete?
Avoid de-icing salt the first winter; use sand for traction while the slab cures and seals. Read more about new concrete care.
Why does concrete crack?
Shrinkage, freeze-thaw, and base settlement cause cracks; control joints direct them. Read more about why concrete cracks.
How long does concrete take to cure?
Walkable in 24 to 48 hours, full strength at 28 days. Read more about cure time.
B.G. Concrete pours concrete across Wood Dale and the NW Chicago suburbs — see our new concrete care guide or call 630-595-1518 for a written figure.