Concrete Problem Guide
Concrete Pitting: What It Is, What Causes It, What Actually Helps
By Mike Romer, Owner · OKGN Concrete Sealing · Updated July 2026
Quick Answer
Pitting is small holes and craters opening up across a concrete surface — from pinholes to coin-sized pockmarks. It happens when weak spots in the surface (air voids, soft cement paste, small aggregate pops) erode and open up under weather, traffic and freeze-thaw. Pitting itself is cosmetic at first, but every pit is a little cup that collects water — and in the Okanagan that water freezes, turning pits into spalls. Sealing can't fill existing pits, but it hardens and waterproofs the surface so pitting stops spreading and the pits stop feeding deeper freeze-thaw damage.
What You're Seeing
What Pitting Is — and What's Happening Underneath
Pitted concrete looks peppered — dozens or hundreds of small holes across the surface, often worst in wheel paths and low spots. Individually the pits are shallow; collectively they make the slab look old and rough, and they hold water, dirt and salt.
Pits start at weak points: entrained air voids near the surface, spots where the cement paste was thin, or small soft aggregate particles that pop out. Weather and traffic open those weak points into visible holes, and each hole then traps the water that drives freeze-thaw damage deeper.
Root Causes
What Causes Pitting in the Okanagan
Surface voids and weak paste
Every slab has microscopic voids near the surface. Where the cement paste over them is thin or weak, traffic and weather wear through and the void opens into a pit.
Freeze-thaw enlargement
Once a pit exists it holds water. That water freezes, expands, and widens the pit — which holds more water. In a climate with 100+ frost days a year, pits grow every winter.
Salt and chemical exposure
De-icers and harsh cleaners etch and weaken the cement paste, accelerating the erosion that opens new pits.
Freeze-thaw is the engine behind most Okanagan concrete damage — see the government climate data for your city in our city-by-city freeze-thaw breakdown.
The Honest Verdict
Sealing stops pitting from spreading — it doesn't fill the pits
A penetrating sealer does two useful things for a pitted surface: it hardens the cement paste (making it more resistant to the erosion that opens new pits) and it waterproofs the slab (so the water sitting in existing pits can't soak in, freeze, and turn them into spalls). What it won't do is cosmetically fill the pits — the surface keeps its texture. If the pitting is light-to-moderate and you mainly want to stop it getting worse, sealing is the right move. If the surface is so heavily pitted you want it smooth again, that's a resurfacing job first — a different trade — and sealing protects the new surface afterward.
Prevention
How to Keep Pitting From Starting (or Spreading)
Seal early — a hardened, waterproofed surface resists the erosion that starts pits and the freeze-thaw that grows them. Rinse off salt in spring, avoid harsh acid-based cleaners, and fix drainage that leaves standing water on the slab.
FAQ
Concrete Pitting: Common Questions
01Can a pitted concrete driveway be saved?
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Usually, yes. Light-to-moderate pitting is mostly a durability problem, not a structural one — the fix is stopping the pits from growing and multiplying, which is what sealing does by hardening and waterproofing the surface. The pits that exist stay (sealer isn't a filler), but they stop feeding water into the slab. Heavy pitting where you want a smooth surface back means resurfacing first, then sealing the new surface.
02What causes small holes in concrete?
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Small holes — pitting — come from weak points in the surface eroding open: air voids near the top, thin cement paste, or small soft stones popping out. Freeze-thaw then enlarges them, because each hole holds water that expands when it freezes. Salt and aggressive cleaners speed the process by etching the cement paste.
03Will sealing make pitted concrete look new?
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No — and anyone who tells you it will is overselling. A penetrating sealer doesn't change how concrete looks; the pits remain visible. What you get is a surface that stops deteriorating: no new water intrusion, dramatically slowed erosion, and pits that stay pits instead of becoming spalls. If appearance is the priority, resurfacing (a different contractor) then sealing gives you both.
04Does road salt cause concrete pitting?
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It's one of the main accelerants. De-icing salt and the meltwater it creates etch the cement paste and keep the surface wetter, so more freeze-thaw cycles run through it each winter — both of which open and enlarge pits faster. Winter salt scaling and salt-driven pitting are the same chemistry. In the Okanagan the fix is to seal (a hardened, waterproofed surface resists the etching and the freezing), go easy on salt in favour of sand, and rinse salt residue off the slab in spring.
Not Sure How Bad Your Pitting Is?
We'll look at it in person and tell you straight — whether sealing is the right fix, or whether you need a repair contractor first. Free, no-obligation, anywhere in the Okanagan.