What's the difference between a broom-finished and exposed aggregate driveway for a home near the Fundy coast where salt air and road salt are constant concerns?

For a coastal Fundy property, both finishes can perform well — but exposed aggregate has a meaningful durability edge in salt-heavy environments, provided the mix and sealing are right.

The difference comes down to surface texture, maintenance, and how each finish holds up when salt air, salt-laden road spray, and freeze-thaw cycles attack the concrete simultaneously. Near the Bay of Fundy — whether you're in Saint John, St. Martins, Hampton, or one of the smaller coastal communities — your concrete faces a more aggressive environment than inland NB properties. Salt air accelerates chloride penetration into the concrete matrix, and road salt from November through April compounds that with additional freeze-thaw cycling at the surface.

Broom-finished concrete is the standard workhorse finish — the concrete is screeded flat and then dragged with a stiff broom before it sets, leaving fine parallel grooves that provide traction. It's the most common driveway finish in NB and the least expensive. The surface is relatively smooth and uniform, which makes it easy to shovel and clean. The trade-off is that the cement paste layer at the very top — called the laitance — is the weakest part of the concrete. In coastal conditions with heavy salt exposure, this paste layer is the first thing to deteriorate. You'll see it as surface scaling and spalling, where thin flakes of the top layer peel away. With a quality air-entrained mix (5-7% air content is your target for coastal NB), proper curing, and a penetrating silane/siloxane sealer applied within the first year and every two to three years after, a broom-finished driveway will serve you well for 25-30 years.

Exposed aggregate concrete removes that vulnerable cement paste layer intentionally. During finishing, the surface paste is washed away — either by surface retarder applied before the pour or by light pressure washing after initial set — revealing the coarse aggregate (stone) embedded in the mix. What you're left with is a textured, pebbly surface where the hardest material in the mix is what faces the weather. Because the weak paste layer is gone, exposed aggregate is inherently more resistant to the surface scaling that salt and freeze-thaw cycles cause. It also provides excellent traction year-round, which matters on a coastal property where frost and ice are regular visitors. The aesthetic is also a step up — the natural stone texture looks sharp and holds its appearance well as it ages.

The practical considerations for your Fundy-area property: exposed aggregate costs roughly $10-$16 per square foot fully installed versus $8-$15 for broom finish — a modest premium for meaningfully better surface durability in your conditions. Both require a minimum 32 MPa air-entrained mix for coastal NB (not the standard 25 MPa used inland), and both absolutely require a penetrating silane/siloxane sealer — this is not optional near the Fundy coast. Budget $40-$80 per gallon for a quality penetrating sealer and plan to reapply every two years given your salt exposure. Avoid acrylic sealers in this environment — they sit on the surface and will peel under NB freeze-thaw conditions.

One thing to discuss with your contractor: aggregate selection matters for exposed aggregate in coastal conditions. Rounded river stone aggregates tend to shed ice and debris more easily than angular crushed stone. Ask what aggregate is available locally and what your contractor typically uses for coastal projects.

For either finish, make sure your contractor specifies a low water-to-cement ratio (0.40 or lower) in the mix design. This is the single most important factor for chloride resistance — a tight, dense concrete matrix slows salt penetration dramatically. Never allow water to be added to the ready-mix truck at the jobsite to improve workability.

Both finishes are professional-only projects. A driveway pour involves coordinating a ready-mix delivery, placing and finishing 8-10+ cubic yards within a narrow time window, and cutting control joints at the right moment. The margin for error is small and the results are permanent.

Need help finding a concrete contractor experienced with coastal NB conditions? New Brunswick Concrete can match you with local professionals for free — browse the directory at newbrunswickconstructionnetwork.com/directory?trade=concrete.