Exposed Aggregate Concrete: What to Know
Exposed aggregate concrete reveals the natural stones within the mix, creating a textured, slip-resistant surface with visual depth. It's made by removing the top layer of cement paste to expose the decorative aggregates beneath—pebbles, crushed granite, river rock, or other stones.
Exposed Aggregate Concrete: What to Know
Exposed aggregate concrete reveals the natural stones within the mix, creating a textured, slip-resistant surface with visual depth. It's made by removing the top layer of cement paste to expose the decorative aggregates beneath—pebbles, crushed granite, river rock, or other stones.
This finish sits between plain concrete and stamped concrete in both cost ($8-14/sqft) and visual interest. It's particularly popular for driveways, pool decks, and patios where slip resistance matters.
What Is Exposed Aggregate?
Standard concrete contains aggregate (gravel and sand) throughout, but it's hidden beneath a smooth cement paste surface. Exposed aggregate finishes reveal this aggregate by washing or brushing away the surface paste before it fully hardens.
The result is a textured surface showing the natural beauty of the stones—their colors, shapes, and sizes create visual interest impossible to achieve with plain concrete.
How Exposed Aggregate Is Created
The Process
- Pour concrete with decorative aggregate (or standard aggregate if natural look is desired)
- Screed and float as normal
- Apply surface retarder that slows curing of the top layer
- Wait until concrete beneath sets but surface remains soft (timing is critical)
- Wash and brush surface to remove paste and expose aggregate
- Cure normally
- Seal after curing
Timing Is Everything
The washing window is narrow—typically a few hours after pouring, depending on temperature and humidity. Too early, and aggregate dislodges. Too late, and the surface won't wash off.
This timing sensitivity is why exposed aggregate is typically professional work, though experienced DIYers can achieve good results on small projects.
Aggregate Options
| Aggregate Type | Appearance | Best For |
|---|---|---|
| Pea gravel | Small, rounded, natural | Patios, walkways |
| River rock | Smooth, varied colors | Natural landscapes |
| Crushed granite | Angular, sparkly | Modern aesthetics |
| Quartz | White/clear, reflective | Bright, clean look |
| Limestone | Neutral, consistent | Traditional homes |
| Seeded aggregate | Decorative stones broadcast on surface | Premium look |
Seeded aggregate involves broadcasting select decorative stones onto the surface after pouring, then exposing them. This allows precise control over appearance but adds cost.
Exposed Aggregate Costs
Exposed aggregate falls between plain and stamped concrete:
| Finish Type | Cost per Sqft |
|---|---|
| Plain broom finish | $4-8 |
| Exposed aggregate | $8-14 |
| Stamped concrete | $12-20 |
What Affects Cost
| Factor | Impact |
|---|---|
| Aggregate type | Premium stones cost more |
| Seeded vs. integral | Seeded adds $2-4/sqft |
| Project size | Larger projects may cost less per sqft |
| Complexity | Borders, patterns add cost |
| Region | Labor rates vary |
Project Examples
| Project | Size | Cost Range |
|---|---|---|
| Small patio | 100 sqft | $800-1,400 |
| Medium patio | 200 sqft | $1,600-2,800 |
| Driveway | 500 sqft | $4,000-7,000 |
| Pool deck | 400 sqft | $3,200-5,600 |
For detailed estimates, use our driveway cost calculator or see driveway cost guide.
Pros and Cons
Advantages
Excellent slip resistance: The textured surface provides superior traction, making it ideal for pool decks, sloped driveways, and areas exposed to rain.
Durability: The exposed aggregate creates a harder, more wear-resistant surface than smooth concrete. Properly maintained, it lasts 25+ years.
Natural appearance: The organic look of natural stones complements landscapes and traditional architecture.
Hides imperfections: Surface variations, minor cracks, and wear are less visible than on smooth or stamped concrete.
Low maintenance: Beyond periodic sealing, exposed aggregate requires minimal care.
Mid-range cost: More interesting than plain concrete, less expensive than stamped.
Disadvantages
Rough texture: The pebbly surface can be uncomfortable for bare feet—not ideal if you'll walk on it barefoot frequently.
Harder to clean: Textured surface traps debris more than smooth concrete. Pressure washing helps.
Repair visibility: Patches don't match well. Repairs are visible (though less than stamped concrete).
Professional installation: Timing the exposure is tricky. DIY is possible but risky.
Limited customization: Unlike stamped concrete, you can't create patterns—just expose what's there.
Aggregate dislodgement: Poor installation or freeze-thaw damage can cause stones to pop out over time.
Best Applications
Excellent For
Driveways: The texture handles vehicle traction well, and aggregate hides tire marks better than smooth concrete.
Pool decks: Superior slip resistance when wet—critical for safety.
Patios: Natural look complements outdoor living spaces.
Walkways: Traction and durability for high-traffic paths.
Good For
Outdoor stairs: Slip resistance adds safety (but texture may be uncomfortable without shoes).
Borders and accents: Combine with broom-finish concrete for visual interest.
Less Ideal For
Barefoot areas: The texture can be uncomfortable (consider this for pool areas where people walk barefoot).
Indoor applications: The rough surface is hard to clean and uncomfortable underfoot.
Areas requiring smooth rolling: Wheelchairs, strollers, and rolling equipment move easier on smooth surfaces.
Exposed Aggregate vs. Stamped Concrete
| Factor | Exposed Aggregate | Stamped Concrete |
|---|---|---|
| Cost | $8-14/sqft | $12-20/sqft |
| Appearance | Natural, organic | Patterned, formal |
| Slip resistance | Excellent | Poor (requires additive) |
| Repair visibility | Moderate | High |
| Maintenance | Low | Moderate (resealing) |
| Customization | Limited (aggregate choice) | High (patterns, colors) |
| Comfort barefoot | Rough | Smoother |
| DIY possible | Difficult | No |
Choose exposed aggregate for: Natural aesthetics, slip resistance, durability, lower cost.
Choose stamped concrete for: Pattern/design flexibility, smoother surface, formal appearance.
See our stamped concrete guide for detailed comparison.
Maintenance Requirements
Regular Maintenance
| Task | Frequency |
|---|---|
| Sweep/blow debris | Weekly |
| Rinse with hose | Monthly |
| Pressure wash | Annually |
| Inspect for loose aggregate | Annually |
| Reseal | Every 3-5 years |
Sealing
Sealing exposed aggregate is important:
- Protects against staining
- Enhances color depth
- Reduces aggregate dislodgement
- Makes cleaning easier
Sealer type: Penetrating sealers work well without creating slick surface. Acrylic sealers enhance color but may reduce slip resistance.
Loose Aggregate Repair
If stones become loose:
- Remove loose stones
- Clean the void
- Apply concrete bonding agent
- Fill with matching aggregate in epoxy or concrete patch
- Allow to cure before sealing
Prevention is better—proper installation and sealing minimize this issue.
Can You DIY Exposed Aggregate?
Technically yes, but it's challenging. The difficulty is timing the wash:
- Too early: Aggregate washes out
- Too late: Surface won't wash off
If attempting DIY:
- Start with a small project (under 50 sqft)
- Use a surface retarder (provides longer window)
- Test timing on a sample
- Have help—you need to work fast
- Accept that first attempts may not be perfect
For most homeowners, professional installation is worth the cost.
Frequently Asked Questions
Is exposed aggregate more expensive?
Yes, typically $8-14 per square foot compared to $4-8 for plain concrete. It's less expensive than stamped concrete ($12-20/sqft). The added cost reflects the decorative aggregate and skilled labor for proper timing.
Is exposed aggregate slippery when wet?
No—the opposite. Exposed aggregate provides excellent slip resistance, making it one of the best choices for pool decks and areas that get wet. The textured surface offers traction that smooth or stamped concrete can't match.
How long does exposed aggregate last?
With proper installation and maintenance, 25+ years. The exposed surface is actually more durable than smooth concrete because you're revealing the hardest part of the mix. Regular sealing (every 3-5 years) maximizes lifespan.
Can you do exposed aggregate yourself?
It's possible but challenging. The timing window for washing is narrow, and mistakes are permanent. Small projects (under 50 sqft) are more forgiving. Use surface retarder to extend your working window. Most homeowners find professional installation worthwhile.
Key Takeaways
- Cost: $8-14/sqft (between plain and stamped)
- Best for: Driveways, pool decks, patios requiring slip resistance
- Lifespan: 25+ years with proper maintenance
- Maintenance: Seal every 3-5 years
- DIY: Possible but timing is tricky—professional recommended
- Key advantage: Excellent slip resistance and natural appearance
Explore other decorative options: stamped concrete and colored concrete. For complete driveway planning, see our driveway guide.