The following information is intended as an overview to the proper installation of concrete paving bricks. These are the steps that would be taken by a reputable contractor who would be providing a guarantee on the work done.
- The first and a very important step is to have the property surveyed for buried cables, power lines and gas pipes before you start digging. Most utility companies provide location services free of charge. All it takes is a phone call. If you excavate without having the location services flag your property, you will be held responsible for any damages and subsequent repairs. Not to mention the fact that cutting into a buried electrical service with a shovel could put you out of commission for a very long time. As well, think of the anguish you might create in the community by cutting off utility services to your neighbors. The primary service companies that should be called are gas, electric, cable TV, and telephone.
- Using stakes and string map out the area to be excavated. The more intricate the area, the more complex the installation and cutting of the paving stones. Remember that paving stones are not flexible and hence tight curves and arches can be difficult to fill.
- Remove the existing pavement, sod, plants, and trees from the area to be excavated.
- Excavate the soil to the required depth. The depth needed is the basic calculation derived from taking the finished surface minus the thickness of the paver, the depth of the setting bed and the depth of the base material. The required thickness of the base material (commonly 4 to 8-inches for patios and walkways and 6 to 12-inches for driveways and roadways) is totally dependent on local soil conditions, primarily the soils reaction to water. The city or county soil engineer will be able to tell you the required thickness of the base material for your area.
- Prior to laying the base material, the sub-grade must be compacted. With a clay sub-grade you will need to use a powered roller or rammer. With a sandy soil the use of a mechanical vibrator, should be adequate to provide proper compaction.
- After the sub-grade is compacted, place a layer of landscape (geotextile) fabric on the sub-grade. It is important that the base material be somewhat isolated from the natural soil, especially in high moisture areas.
- Use a granular base material that compacts easily on top of the landscaping fabric. The material should be laid in 2 to 4-inch layers, or lifts as it they are called within the industry, with each layer being individually compacted. It is impossible to get proper compaction in a layer that is thicker than 4-inches no matter what type of compacting equipment is employed. The base material goes under numerous names ("type 2 base", "AB3", "21A" or "3/4 minus") depending on where you are located. Your local concrete paver supplier will know the material to be used as a base for installing the pavers.
- Once the granular base material has been compacted, install edge restraints along the border, on top of the base material using steel spikes to secure them in place. The edge restraints are a key part of the potential longevity of the paver installation as they provide lateral load resistance and provide continuity to the interlocking characteristics of the paving stones. Without the edge restraints, the paving stones will separate and spread over time.
- Lay the setting bed, to a depth of 1 to 1.5-inches, on top of the compacted base material and spread it evenly across the entire project area. The setting bed is usually a material of washed coarse concrete sand or granite stone dust.
- You are now ready to install the pavers in your chosen pattern. As a general statement, it is best to start at one end of the project and in the middle of the area (there are some exceptions with complex patterns. Do not place edge pavers first as you cannot be sure of their precise location. If it is a large project and you have several skids, take pavers randomly from all skids to ensure that any color variations between the individual skids are blended within the total project.
- The paving stones are down, but you are not quite finished! Sweep sand over the top of the pavers and fill the gaps between the pavers. Use a vibrating compactor, over the entire project, to force the sand to completely fill the gaps between pavers (sweep additional sand as necessary). The process of vibrating sand into the gaps creates an amazingly solid and stable surface.
- Last but not least, remove any excess sand that has accumulated from the previous step and apply a protective sealing finish to your project. A sealer will highlight the paver colors and protect the stones from staining. The sealer should be applied at regular intervals, follow the manufacturer's instructions.
Tip 1: If it rains during the compacting phases of the sub-grade or the base material, make sure that the ground has dried out completely before you continue.
Tip 2: Remember drainage when grading the soil. You should allow for a slope of 0.25-inch per foot to allow water to run off the finished project.
Tip 3: Don't be afraid to use a level during all phases.
As with all home improvement and landscaping projects, planning and knowledge are the keys to success.
For additional information on pavers, landscaping or other home improvement projects, visit Renovation Headquarters