Paving a surface with exposed aggregate gives a landscape the long-lasting benefits of concrete with the decorative appearance of small, colourful pebbles. While there are several ways to expose aggregate, seeding the surface with pebbles is one of the simplest. Laying an exposed aggregate finish over wet concrete is time consuming and laborious, but the results can be stunning. You'll need to install a gravel foundation and pour a concrete slab into forms before adding the finish.
Shovel pea gravel onto a freshly poured concrete surface about 20 minutes after it is poured. Spread the gravel with a sweeping motion so it sprinkles evenly over the surface. Spread out any piles with a soft broom.
Mix enough concrete to cover the surface with a thin top layer. Stir a proportion of 3 parts sand, 1 part cement and enough water for a thin consistency. Pour the mix over the aggregate surface to fill in the gaps between stones.
Lay a board over a section of aggregate. Step on both ends of the board or hit it gently with a hammer to apply even pressure so the aggregate below sinks evenly into the concrete. Repeat this process across the entire surface. If you're laying exposed aggregate over a large area, have several people press the gravel in so the entire surface is covered before the concrete is too hard. Wait one hour for the surface to dry.
Brush the pavement with a soft shop broom until the shape of the decorative gravel shows through. Spray the area with a hose to clean removed concrete from the gravel. Continue to brush only the thin top layer from around the stones so you don't overexpose them.
Lay wet breathable fabric like burlap over the exposed aggregate surface to prevent it from drying out too fast. Wait about two weeks for the surface to fully cure.
Apply clear sealant with a roll brush over exposed aggregate to strengthen the surface. Use a product designed specifically for exposed aggregate concrete to protect it from water permeation, sun damage and stains.
Things you need
- Pea gravel
- Soft broom
- Clear sealant
- Roll brush