Why Is My Concrete Flaking? Scaling, Spalling and Deicers in Spokane: Causes, Prevention and Repair (2026)

If the top of your driveway, garage apron or front walk is peeling off in thin flakes after a Spokane winter, you're looking at scaling. It's one of the most common concrete complaints in freeze-thaw country, and it usually isn't a sign the slab is failing structurally. It is a sign the surface took on water and deicer and then froze. Here's what causes it, how it differs from spalling, and what actually prevents it.

Scaling vs. spalling vs. popouts

People use these words loosely, but they describe different problems:

• Scaling: the top skin of the concrete flakes or peels away, usually starting thin and spreading. Industry groups describe it as a surface problem driven mainly by wet freeze-thaw cycles and deicing chemicals
• Spalling: deeper pieces break off, often at joints, edges or over rusting rebar or wire mesh close to the surface
• Popouts: small cone-shaped pits where an individual piece of weak or porous aggregate near the surface expanded and popped

Scaling is the one tied most closely to winter, deicers and how the concrete was mixed, finished and cured.

Why Spokane concrete is at risk

• Severe weathering: the City of Spokane's engineering design standards and Spokane County's permit design criteria put our area in the severe weathering category
• A long freeze season: at Spokane International Airport, average lows sit below freezing from November through March (NOAA 1991 to 2020 normals)
• Deicer exposure: salt and slush tracked in on tires end up on driveways, aprons and garage floors whether you salt them yourself or not

What actually causes scaling

The Pennsylvania Aggregates and Concrete Association describes scaling as a symptom of specification, construction, curing and exposure, typically triggered by wet freeze-thaw cycles and aggressive deicer use. The Federal Highway Administration explains the mechanism: ice forming in concrete's pores is expansive, and the tiny air voids deliberately entrained in the mix play a critical role in freeze-thaw durability. Deicer solution keeps the surface wetter, so when that saturated layer freezes without enough air voids near the top, the surface lets go.

The usual contributors:

• Not enough entrained air, or air knocked out during finishing
• Too much water in the mix, often added on site to make it easier to place, which weakens the surface
• Finishing too early, working bleed water back into the surface, or hard steel-troweling exterior concrete
• Poor or skipped curing, so the surface never gains full strength
• Deicers too soon, before the concrete has cured and had a period to dry out
• Aggressive deicers that chemically attack concrete at any age

What the code and industry guidance call for

Washington's residential code ties exterior concrete to a specific mix. Under IRC Table R402.2, porches, steps exposed to weather, carport slabs and garage floors in a severe weathering area need at least 3,500 psi at 28 days, and the concrete must be air-entrained with 5 to 7 percent total air by volume. The same table limits how much fly ash, slag and similar materials can go into garage slabs and exterior flatwork exposed to deicing chemicals.

Concrete industry groups that publish scaling guidance add:

• Water-cement ratio: keep the water-to-cementitious materials ratio at 0.45 or lower (the Pennsylvania Aggregates and Concrete Association and Ohio Concrete both use this figure)
• Air content: 5 to 8 percent entrained air is the range the Pennsylvania association recommends for scale resistance
• No water added on site beyond what the mix design allows
• Wait to finish until bleed water is gone and the surface has stiffened
• Cure right away with a curing compound or wet covering
• Seal before the first freeze-thaw cycles with a quality penetrating sealer

Deicers: what to use and when

This is the part homeowners control, and it matters most in the first winter.

• First winter, no deicers: concrete associations recommend skipping deicing chemicals during the concrete's first year, especially for concrete poured late in the season. Use clean sand or kitty litter for traction instead
• Why fall pours are riskier: the Michigan Concrete Association notes that concrete placed late in the season, such as October or November, may not get enough drying time, which it puts at 30 days, before deicers show up.
• Never use ammonium-based products: Ohio Concrete warns that ammonium-based salts and fertilizers chemically attack hardened concrete, and the Pennsylvania association says to avoid deicers that chemically attack concrete at any time
• Older concrete: the associations don't fully agree here. Ohio Concrete says rock salt (sodium chloride) and calcium chloride are considered acceptable on concrete over a year old when used per the label, while the Michigan Concrete Association says to never use calcium- or magnesium-based deicers on concrete and to use sodium chloride in moderation. Plain rock salt, used sparingly, is the choice both accept
• Use less and clear it fast: shovel or sweep off slush and leftover deicer promptly, and hose off salt that drips from vehicles onto a new driveway or garage floor when the weather allows

Can scaled concrete be fixed?

It depends on how deep and widespread the damage is.

• Light, early scaling: cleaning and a penetrating sealer can slow it down, though it won't restore the lost surface
• Moderate scaling: a bonded resurfacing or overlay product can work if the slab underneath is sound, but it needs careful prep and won't hold over a weak, still-flaking surface
• Deep or widespread scaling, or scaling with cracking and settling: replacing the section is often the more durable answer, and it's the chance to get the mix, finishing and curing right

We look at the slab in person before recommending any of these, because the right answer depends on what's underneath.

What we do on every exterior pour

• Air-entrained mix ordered to the code minimum or better for Spokane's severe weathering
• No extra water at the truck beyond the mix design
• Finishing timed to the concrete, with a broom or textured finish on exterior flatwork instead of a hard trowel
• Curing compound or covering right after finishing, and cold-weather protection when the forecast calls for it
• First-winter care instructions for every customer, including the no-deicer rule

Related guides: should you seal your concrete driveway in Spokane, why concrete driveways crack, pouring concrete in winter, when you can drive on new concrete and broom vs. exposed aggregate vs. stamped finishes.

Get your flaking concrete looked at

If your driveway, walk or garage apron is scaling, Raven Buildings can tell you whether it's a resurfacing job or a replacement and quote it. Call 509-350-2016 or request a free quote. See our concrete services.

Sources

• FHWA Tech Brief, Air Entrainment and Concrete Durability (PDF)
• Pennsylvania Aggregates and Concrete Association, Reducing Concrete Scaling (PDF)
• Ohio Concrete, Scaling Concrete Surfaces (PDF)
• Michigan Concrete Association, Preventing Scaling of Concrete Surfaces in Michigan (PDF)
• Washington State Residential Code 2021, Chapter 4 Foundations (Table R402.2)
• City of Spokane BUILD-21 Engineering Design Standards (severe weathering)
• Spokane County BP-06, Residential Building Permits (design criteria)
• NOAA NCEI 1991 to 2020 Monthly Normals, Spokane International Airport