An exposed aggregate driveway is a driveway made of pre-cast concrete pieces. The pieces are arranged in patterns to create ornamental designs or increase traction. These drives are usually poured onto an existing gravel surface, but they can also be constructed using solid asphalt, crushed stone, and other aggregates recast as concrete mixtures.
The concrete mixture is made from a portland cement binder combined with fine aggregates such as sand or pebbles and larger coarse aggregates such as gravel or crushed stone. A levelling layer must be added before the material sets to keep it smooth and even across the ground’s surface. When dried, this material has a rough exterior texture because of the exposed aggregates. Eventually, it will weather to a smoother surface, but it will never be as polished as a poured concrete driveway.
An exposed aggregate drive is relatively low-maintenance and strong. It can be designed with intricate patterns that enhance the beauty of your home’s exterior and provide resistance against uneven ground or gravel movement underneath the concrete. This type of driveway does not become slick when wet and is less likely to catch debris than other surfaces. However, it is easily damaged by heavy traffic or high temperatures and may require repair after severe weather events because sutured pieces can crack under pressure.
Approximately 1 foot of gravel should be placed over the compacted earth before the first course of material is applied to create an even base for your new drive. Then, additional courses of exposed aggregate driveway material should be added until the desired height of your drive is reached.
The installation process is similar to that of laying a standard concrete driveway, but each piece must be dry-fitted and not poured all at once; this ensures that the pieces will fit properly over the gravel base. A metal or wood wedge can also be used to separate individual pieces. To provide an even flow during the pour, make sure the courses are level with one another by using shims or water as levelling agents. Once all courses have been laid, remove any excess debris with a broom before allowing them to cure overnight. The final step in installing your new exposed aggregate driveway is to compact it for maximum strength and durability. If you want to increase its traction, you can also apply an oil-based sealant.
An exposed aggregate driveway requires very little maintenance to keep it looking great, but the pieces must be swept clean or blotted with a damp cloth after every rainstorm. In addition, aggregate surfaces do not drain well and can hold water for days; this may cause damage to your garage flooring if the moisture freezes and thaws over time. To avoid cracking, make sure any plantings around the perimeter of your drive are mulched, so their roots don’t come into contact with the concrete mixture. Plantings shou
ld be kept at least 3 feet away from the edges for proper airflow and drainage.
Cracks in exposed aggregate surfaced usually occur because too much water was added to the mixture or because it did not receive a heavy enough compaction. These cracks, which can be up to 1/4 inch wide, should be filled with sandable filler and coated with a sand-based sealant.
Suppose you want your new exposed aggregate driveway to maintain its high level of quality for years into the future. In that case, it is essential that you follow all installation instructions exactly as they are described by the manufacturer. If you have concerns with how to proceed with a specific step in the process, do not hesitate to contact a professional contractor for advice before moving forward.