Exposed aggregate has been a popular hardscape material in Sonoma County landscapes for decades. At Details Landscape Art, we have been installing patios, walkways, driveways, and steps since 1991, using a variety of materials including flagstone, brick, stamped concrete, and tile.
While flagstone and stamped concrete have dominated recent design trends, exposed aggregate remains an excellent lower-cost alternative that combines beauty, durability, and value.
Styles change over time. When we first started in business in the early 1990s, exposed aggregate was all the rage. We learned our craft well and became especially skilled at installing this product, a specialty that we still offer today.
Why Choose Exposed Aggregate?
It offers several advantages over other hardscape materials.
It is durable, attractive, slip-resistant, and generally less expensive than flagstone or brick. The exposed stone creates texture and visual interest while providing a surface that performs well in wet weather and around swimming pools.
We especially like it when combined with complementary accents such as brick borders, flagstone trim, or contrasting concrete colors.
Exposed aggregate with black brick trim
Natural Exposed Aggregate
Concrete consists primarily of cement and aggregate, or rock.
In Sonoma County, the aggregate is typically gray river rock in sizes ranging from 3/8 inch to 3/4 inch. After the concrete is poured, floated smooth, and properly finished, the curing process begins.
At a critical point during curing, the surface cream is gently washed away, exposing the aggregate beneath.
The amount of washing is important. Too little washing leaves the stones hidden beneath the surface. Too much washing exposes too much rock and creates a rough surface that may be uncomfortable to walk on barefoot.
Our goal is what contractors call a “light wash,” exposing enough aggregate to create texture and beauty while maintaining a comfortable walking surface.
Seeded Exposed Aggregate
Seeded exposed aggregate takes the process one step further.
After the concrete is poured and floated smooth, decorative stones are broadcast or “seeded” onto the surface while the concrete is still wet. The stones are then worked gently into the surface before final finishing.
As the concrete cures, the surface cream is washed away, ‘exposing’ the decorative seed rock.
This process allows us to use a variety of attractive aggregates that would not normally be present in standard concrete.
Popular decorative aggregates include:
- Pami Pebbles
Exposed aggregate using Pami pebbles - Salmon Bay
- Trinity
- Salt and Pepper
- Mexican Pebbles
The additional materials and labor required make seeding somewhat more expensive than natural exposed, but many homeowners feel the appearance is well worth the additional cost.
Combining Exposed Aggregate with Other Materials
One of our favorite design approaches is combining exposed aggregate with complementary hardscape materials.
Brick borders can provide definition and contrast. Flagstone accents can create a more custom appearance. Decorative steps and seat walls can be coordinated with the aggregate surface to tie the entire landscape together.
The result is a hardscape that feels more customized and visually interesting than a single material used throughout the project.
Sealing and Maintenance
Aggregate can be sealed or left natural depending on the homeowner’s preference.
A quality sealer enhances the color of the aggregate and can help protect the surface from staining and weathering. Others prefer the more natural appearance that develops as the concrete ages.
Maintenance is generally minimal. Periodic cleaning and occasional resealing, if desired, are usually all that is required to keep the surface looking its best.
A Proven Hardscape Material
Some landscape materials come and go with changing trends. Exposed aggregate has remained popular for decades because it offers an excellent combination of appearance, durability, and value.
At Details Landscape Art, we have installed beautiful patios, walkways, driveways, and steps throughout Sonoma County. Whether used alone or combined with brick or flagstone accents, exposed aggregate continues to be a practical and attractive choice for homeowners seeking a durable hardscape surface that stands the test of time.