Walk through almost any established Salt Lake City neighborhood and you’ll find exposed aggregate concrete — the distinctive pebbled finish where colorful stones are visible at the surface. It’s been a popular choice for driveways, patios, and walkways for decades, and its enduring popularity is well-deserved. Exposed aggregate is attractive, highly textured for slip resistance, and holds up well in Utah’s demanding climate. Here’s a complete guide to this versatile finish option.
What Is Exposed Aggregate Concrete?
Exposed aggregate is concrete in which the surface cement paste has been washed away during finishing to reveal the stone aggregate beneath. The result is a textured surface studded with visible pebbles or stones. These can be standard rounded river rock (the classic look), decorative specialty aggregates like quartz, granite chips, glass, or colored stone, or simply the natural aggregate in the ready-mix concrete if it has visual appeal. The aggregate can be “seeded” onto the fresh concrete surface for a more controlled appearance, or the aggregate already in the mix can be exposed for a more random look.
Why It Works Well in Salt Lake City
Several characteristics make exposed aggregate particularly appropriate for the Wasatch Front. The natural stone texture integrates beautifully with Utah’s desert and mountain landscape aesthetic — earth tones, warm browns, and terra cotta tones found in local aggregates complement the natural environment. The textured surface provides excellent traction in wet or icy conditions, important for Salt Lake City driveways and walkways during winter. And because aggregate — rather than the cement paste — is what you see, normal wear from freeze-thaw cycling affects the appearance less dramatically than it does on smooth concrete.
Choosing Your Aggregate
The aggregate you choose determines the character of the finished surface. Options available from Salt Lake area concrete suppliers and landscape material yards include: local river rock (warm brown and tan tones, rounded, classic appearance), pea gravel (small, uniform, smooth), quartz aggregate (sparkles in sunlight, available in many colors), basalt (dark, dramatic), limestone (light tan, common in Utah), and decorative colored glass or specialty stones for distinctive custom looks.
Consider scale: small-diameter aggregate (3/8 to 5/8 inch) works well for walkways and patios where foot traffic is the primary use. Larger aggregate (3/4 to 1 inch) creates a bolder texture appropriate for driveways and larger expanses. Seeded aggregate gives you the most control over the finished appearance and is the method used when premium decorative stones are specified.
Installation Process
Exposed aggregate is installed using standard concrete methods with an additional finishing step. Concrete is poured, screed, and floated normally. During the finishing window, after initial stiffening, a chemical surface retarder is sprayed onto the surface. This retarder slows the hardening of the surface paste while the underlying concrete continues to set. The following day, workers use a stiff broom and water to wash away the retarded surface paste, revealing the aggregate beneath.
Timing and technique are critical — the exposure window is narrow, and washing too early removes too much paste; washing too late leaves the surface too hard to expose properly. This is skilled work that benefits significantly from an experienced contractor.
Sealing Exposed Aggregate in Utah
Exposed aggregate should be sealed to protect both the stones and the surrounding matrix from freeze-thaw damage and staining. A penetrating silane-siloxane sealer is the best choice for driveways and walkways — it protects against moisture without changing appearance. A solvent-based acrylic sealer is used when an enhanced, wet-look finish is desired on patios. Apply sealer once the concrete has cured fully (28 to 30 days), and reapply every 2 to 3 years to maintain protection in Salt Lake City’s conditions.
Maintenance
Exposed aggregate is relatively low-maintenance. The textured surface holds some dirt and organic material in the aggregate pockets, which requires periodic power washing to keep the surface looking its best. Annual or biannual pressure washing with a concrete cleaner maintains appearance effectively. Apply concrete-safe ice melt alternatives (sand or CMA) rather than chloride-based products in winter — salt can bleach and damage the aggregate surface over time.
Cost in the Salt Lake City Market
Exposed aggregate concrete runs $8 to $18 per square foot installed in the Salt Lake area, depending on aggregate type, complexity, and project size. Standard river rock exposed aggregate is at the lower end; premium seeded aggregate with specialty stone at the higher end. This compares favorably to pavers ($10 to $25/sq ft) and natural flagstone ($15 to $35/sq ft) while providing a more durable, monolithic surface.
Design Ideas for Salt Lake City Homes
Use exposed aggregate as a border around a standard brushed concrete driveway field for a sophisticated two-tone look. Combine smooth stamped concrete with an exposed aggregate apron at the street entrance. Use small-aggregate exposed concrete for garden paths through a naturalistic yard design. For mountain-area homes in neighborhoods like Holladay or Sandy, use locally sourced river rock aggregate to connect the hardscape to the surrounding natural environment.
Final Thoughts
Exposed aggregate concrete is a time-tested finish that works beautifully in Salt Lake City’s landscape and climate. It’s more distinctive than standard brushed concrete, more durable than most pavers in freeze-thaw conditions, and genuinely attractive when executed with quality aggregate. If you’re planning a driveway, patio, or walkway project, exposed aggregate deserves serious consideration alongside other finish options.