Exposed Aggregate
Exposed Aggregate Concrete in Tacoma & South Sound
Exposed aggregate is concrete with the top layer washed away to show the rock underneath. The crew pours, floats, applies retarder to the surface, then pressure-washes the next day to reveal the stone. The result is a textured, natural-looking finish with built-in traction. Our team uses it on driveways, patios, and walkways across Tacoma and the South Sound.
How exposed aggregate is done
The process from pour to finished surface.
Standard slab prep and pour
Compacted base, forms, rebar or mesh, and air-entrained concrete. Same foundation as any flatwork job.
Surface retarder application
After the slab is floated, a chemical retarder is sprayed or rolled onto the surface. This keeps the top layer of cream from hardening while the rest of the slab cures.
Pressure wash to expose the rock
The next morning, the crew pressure-washes the retarded surface layer off. The aggregate underneath is now visible and locked in place. Then it gets sealed.
Why homeowners pick exposed aggregate
The practical reasons behind the finish.
- Natural look: the stone in the mix creates a speckled, textured surface that blends with landscaping and natural surroundings.
- Traction: the exposed rock provides natural grip, even when wet. Good for driveways, pool decks, and walkways where people need solid footing.
- Hides wear: small scuffs, tire marks, and everyday wear are much less visible on an exposed surface compared to smooth or broom-finish concrete.
- Pairs well with decorative borders: a stamped or colored border around an exposed aggregate center is one of the most popular combinations our team pours.
- PNW friendly: the textured surface handles rain and light frost better than smooth concrete. Sealed aggregate resists moisture absorption.
Common questions
Exposed Aggregate FAQ
Does exposed aggregate cost more than broom finish?
Yes. The surface retarder, extra wash step, and sealer add to the cost. Expect 20-30% more than standard broom-finish concrete. Still less than stamped or natural stone.
Can you choose the type of rock?
To a degree. The aggregate in the mix is determined by the batch plant, but you can request specific rock blends or supplemental aggregate for a particular look. Most projects use the standard local mix, which includes pea gravel and river rock native to the PNW.
How often does it need resealing?
Every 2-3 years for best results. Sealer protects the exposed rock from staining and moisture. Without it, the surface can darken unevenly and collect dirt in the texture.
Is exposed aggregate slippery?
Less slippery than smooth or stamped concrete. The raised rock surface provides natural traction. It is one of the better finishes for areas that get wet regularly.
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