Which Is the Right Base for Underneath My Patio? – Concrete vs. Recycled Concrete Aggregate (RCA)
In the patio and masonry industry, we are often asked by clients what the best base for a patio is. We have found that many of our customers are confused by this topic because every contractor has their own way of installing patios. In this blog, you will learn about the pros and cons of concrete and RCA sub bases, where and when to install both types, and the actual installation processes for both.
Recycled Concrete Aggregate (RCA) – Crushed Stone Base
Here in Suffolk County, Recycled Concrete Aggregate (RCA) is one type of material that has been used for masonry projects. RCA is essentially concrete that is broken down into small pieces and filled with concrete powder. When compacted, it locks
together and makes a strong footing, also allowing for proper drainage. RCA is used for a sub base, so you may find this type of material under driveways, walkways, patios, pool surrounds, and much more.
For a sub base application, you will want to remove the dirt in the project area at the recommended amount. Depending on the purpose of the area; a patio, driveway, or a new pool, excavation amounts may vary. Looking at a patio for instance, a recommended RCA base of 4-6 inches is needed. Whereas, on a driveway with pavers, 10-16 inches is needed, as it must withstand the weight of vehicles on top. With that said, you want to ensure you are installing your base in 2 inch lifts/intervals – with sufficient compaction after each. Two inch lifts/intervals refers to installing your base 2 inches thick and then compacting the area and repeating the process until you reach the required depth. A mechanical compactor can only properly compact a sub base of 2-3 inches, which is why working in stages is crucial.
One of the reasons a manufacturer recommends a crush stone base is because it allows for proper drainage. Pavers and Polysand are permeable to an extent, so any water that goes through the surface has a place to drain – you do not want water trapped in between the pavers and the base! When water does get trapped in between, efflorescence or damp pavers may occur.
Overall, an RCA base can be easily repaired, and in some cases, in just a few short minutes. If you are looking for a sub base that is cost effective and still durable, Recycled Concrete Aggregate is the perfect material for the job.
Concrete Sub Base
In some cases, contracting companies on Long Island may install a 4 inch concrete base underneath a patio, which may be a completely viable option, depending on certain factors. At affordablepatio.com, we typically install a 4 inch concrete base when dealing with a new pool or driveway. The reason that concrete is a great base for a new pool is because new pools have been excavated around, which means that you are no longer working with virgin soil. We also use concrete for driveways, as it is sufficient enough in supporting the weight of cars on top.
With that said, we do not believe every job needs a concrete base, since there may be instances where you run the risk of getting efflorescence. Efflorescence is the curing of the concrete that may bleed into the pavers and cause a white caulk look to your newly installed stonework.
Our hope here at affordablepattio.com, is for the information that we provide to you, helps you to understand which application is the best fit for your space. In our line of work, we use both types of material (RCA and concrete) as a sub base and believe strongly that when they are used appropriately, they can be very effective. Over the past 15 years being in business, we have seen both RCA and concrete move and settle with time. So, when one of our team members arrives for an estimate, we will make sure to tell you what application we believe will best fit your needs and existing space.