A long lasting brick patio, driveway, or walkway is the result of a properly installed base. As with anything, foundation is the key. By the time you’ve finished reading this post on base installation you should know almost everything you need to know about installing paver base.
The first thing we must do is consider the excavation depth. The determining factors include things such as paver thickness and the application of the surface whether it be for pedestrian or vehicular use. Now there are a lot of advanced factors that can be considered, however, I’m just going to cover the basics and as a rule of thumb should be all that you need to achieve a structurally sound foundation for your paver surface. So to determine the excavation depth we need to know the thickness of the paver and the necessary thickness of base.
Determining the base depth is actually very simple. For pedestrian only applications, it is adequate to have a 6″ base. For light to medium duty vehicle applications it is adequate to have 10″ of base. In some locations base is deemed unnecessary, i.e. Florida. However, I say base is necessary regardless of the location.
Installing the base
Once the area has been excavated to the right depth and width (excavate wider by however many inches you have in base depth on each side) it’s time to compact the subgrade. For certain, there are more advanced techniques that we follow in compacting and testing subgrade compaction, but for the sake of the do-it-yourselfer I’m just going to give you the basics. Start by spreading a 1″ layer of base material over the subgrade and run your vibratory plate compactor over the base 2 times in each direction. This will give a pretty good compaction to the subgrade preparing it for the remainder of base to be installed (high clay soils may require additional compacting techniques to achieve prime compaction as clay is compacted by kneading rather than vibrating).
Continue by adding base material lifts or layers of 2″ at a time and compacting each lift twice in each direction. You may need to add moisture to the base material if it is dry. An indicator of dry base is dry dust being generated during compaction as well as material piles or trails that are created by the sides of the compactor.
Once you have lifted the base to the proper height it is important to check for low and high spots. As a rule of thumb, we generally try to achieve no more than a +/- 1/4″ variation in base height. The base should resemble the expected final patio/driveway appearance leaving way for a consistent 1″-1 1/4″ sand setting bed.
Notes: It is important that during compaction the entire plate be in contact with base material. Fill in any low areas or level off any high areas in the base prior to compacting. If a compactor approaches a small low spot, the plate of the compactor will bridge over the low spot and that particular spot may never receive compaction resulting in future settling of the paver surface.