Exposed Aggregate Concrete Driveway Guide

What Is an Exposed Aggregate Concrete Driveway?

An exposed aggregate concrete driveway is created by pouring a standard concrete mix embedded with decorative stones or pebbles, then carefully removing the top cement paste to reveal the colorful aggregate underneath. The result is a rugged, slip-resistant surface that hides stains and stands up to decades of vehicle traffic.

Homeowners love the custom look—choose from river rock, quartz, granite, recycled glass, or even seashells—while contractors appreciate the straightforward installation process that uses familiar concrete tools.

Top 5 Benefits of Choosing Exposed Aggregate

1. Built-In Traction

Because the stones remain slightly proud of the surface, tires grip even when the driveway is wet or covered in light snow. No need for salt-heavy de-icers that damage standard concrete.

2. Extreme Durability

With a 6-inch thick, 4,000 psi concrete base plus a low water-cement ratio, exposed aggregate easily supports SUVs, RVs, and garbage trucks without rutting or spalling.

3. Hide-and-Seek Maintenance

Oil drips, tire marks, and leaf stains disappear among the multicolored stones. A simple annual pressure wash keeps the driveway looking new.

4. Design Flexibility

Borders, bands, and custom logos are easy to add by switching aggregate colors or seeding contrasting stone into specific areas before the surface is washed off.

5. ROI & Curb Appeal

Real-estate agents consistently rank upgraded driveways in the top three outdoor projects for resale value. Expect 70–80 % cost recouped at sale.

Planning Your Project Like a Pro

Set a Realistic Budget Window

National averages for 2024 fall between $10–$18 per square foot installed. A 20×40 ft (800 sq ft) two-car driveway therefore ranges $8,000–$14,400, including tear-out of old pavement. Add 10 % contingency for unforeseen soft spots or color upgrades.

Check HOA & City Rules Early

Many municipalities classify driveways as “impervious surface.” If you exceed lot-coverage limits, you may need storm-water retention. HOAs often restrict color palettes—bring a sample board to the design-review meeting to avoid costly re-pours.

Decide on Seeded vs. Mix-Design

• Seeded: Base concrete placed, then aggregate broadcast by hand and troweled in. Cheaper, but may create inconsistent stone density.
• Mix-Design: Aggregate blended throughout the load. Higher material cost (extra stone + trucking), yet color runs deeper, allowing future crack repairs to match.

Choose the Right Aggregate

Pea gravel (⅜") feels smooth under bare feet; ¾" river rock adds dramatic texture but may twist high-heel shoes. Darker stones absorb heat and melt snow faster; light quartz stays cooler in summer climates.

Step-by-Step Installation Guide

1. Site Prep & Base

1. Call 811 for utility locates.
2. Remove old pavement to a minimum 8" below final grade.
3. Install 4" of compacted crushed concrete (21AA) in 2-inch lifts; plate-compactor passes until no visible footprints remain.
4. Add geotextile fabric if soil is clay-heavy to prevent future settlement.

2. Forming & Reinforcement

Use 2×4 or 2×6 lumber braced every 3 ft. Driveway should slope ⅛" per foot toward street or swale. Lay #57 rebar on 2-inch plastic chairs or 6×6-inch wire mesh pulled up into the pour—middle third of slab equals strongest placement.

3. Concrete Placement

Order 5–7 % air entrainment for freeze zones. Keep slump ≤ 4 inches to reduce stone migration. After screeding, bull-float once; excess floating draws paste upward and can weaken exposure later.

4. Surface Retarder Application

Spray a water-based retarder (type “EX” for same-day wash) evenly at manufacturer-listed coverage—usually 100 ft² per gallon. Shield adjacent garage slabs with plastic to prevent accidental staining.

5. Washing & Brushing

Wait until concrete reaches a surface PSI of 1,500 (typically 4–8 hours in 70 °F). Use a 3,000 psi pressure washer with 15° tip held 12 inches away. Begin at the top of the slope and work downward. Lightly scrub with a soft-bristle broom to loosen stubborn paste. Stop when aggregate is uniformly exposed ⅛–¼".

6. Control Joints

Saw-cut ¼-depth joints within 24 hours using a ⅛" blade on a walk-behind saw. Spacing formula: slab thickness (inches) × 24–30. Example: 6" slab = cuts every 12–15 ft. Align with existing sidewalk joints for visual continuity.

7. Curing & Sealing

Apply a breathable acrylic sealer after 28 days. Two thin coats (cross-rolled) deliver UV stability and deepen stone color. Re-seal every 2–3 years or when water no longer beads.

Low-Effort Maintenance Checklist

Spring

• Pressure wash on low setting to remove winter salts.
• Inspect joints; refill with polyurethane caulk where gaps exceed ¼".

Summer

• Re-seal if beading fails the “splash test.”
• Trim nearby tree roots to prevent slab uplift.

Fall

• Blow or rake leaves weekly; tannic acid can etch sealer.
• Apply magnesium-chloride ice preventer before first freeze—safer for concrete than rock salt.

Winter Care

Use plastic shovels; metal blades can chip exposed stones. Spread sand for traction instead of continued de-icer applications.

Common Problems & DIY Fixes

Small Pop-Outs

If a single stone dislodges, vacuum the cavity, dampen, and press in a premixed polymer-modified concrete patch blended with matching aggregate saved from original install.

Hairline Cracks

Clean crack with 150-psi air wand, fill with gray self-leveling sealant, then dust exposed surface with matching sand to camouflage.

Oil Stains

Cover with kitty litter overnight, sweep, then scrub with biodegradable degreaser. Avoid acids—they dull sealer and etch cement paste.

Sealer Whitening

Usually caused by moisture trapped under thick coats. Strip with xylene-wipe or hire a pro for light grind and re-seal.

Exposed Aggregate vs. Other Driveway Options

Stamped Concrete

Offers tile or brick patterns, but surface coloring can fade and sealer needs yearly refresh. Stamped averages $12–$20 per sq ft—similar upper range to aggregate—yet provides less slip resistance.

Pavers

Individual brick units allow spot repairs, however edge restraint can fail and weeds sprout in joints. Lifetime cost creeps higher due to polymeric sand renewal every 5 years.

Standard Broom-Finish Concrete

Cheapest at $6–$10 per sq ft, but plain gray shows stains instantly and lacks upscale appearance. Aggregate offers mid-range cost with premium aesthetics.

Hiring the Right Contractor

Must-Ask Questions

• “Do you use a mix-design or seeding method, and why?”
• “Can you provide a 24-hour test board with my chosen aggregate?”
• “What retarder brand and wash-window do you follow?”
• “Is saw-cutting included, and at what spacing?”
• “Will you supply a written sealer schedule with warranty?”

Red Flags

Demands full payment before pour, refuses to share batch ticket, or claims “no joints needed.” Proper contractors hold at least $1 M liability and offer 1–2 year workmanship warranties.

Frequently Asked Questions