How to Build a Paver Patio
Please realize, there is a lot of science that goes into a well built paver patio. The trade association “ICPI” institute of concrete paver installers has spent decades fine tuning their recommendations based on soil and base material scientific calculations. Large commercial jobs (vehicular) require soil analysis, compaction testing and base material approval to verify that a site is properly prepared to meet required standards. These standards use the DOT & paving industries immense experience in several areas to help establish the steps and material requirements I am telling you in this “how to install pavers guide.”
Following the instructions here will not guarantee your paver project will not fail. There are other factors I will not cover here. However, I can guarantee failure if you skip a few of these steps. I do not recommend any do-it- yourself-er attempt a vehicular install, as there is simply too much material and too many opportunities to make rookie mistakes. You would be better off with gravel than a failed paver project.
First of all, The ICPI doesn’t recognize the standard Box store paver (2 3/8” thick or 45mm) as a proper paver. 60mm is the industry standard for a proper paver installation. The thinner pavers are built to inferior standards established by the box store Corporate buyers. 45mm pavers are simply not thick enough to withstand any traffic load over pedestrians, (like golf carts & commercial mowers, much less vehicular loads.) So- you’re thinking… thicker base? Ok, that may help. But why not just use a proper paver, base and edge restraint to start with?
Here are the steps you should follow to a proper install:
- Excavate a minimum of 4” for patios and walk ways (6-10” for driveways).
- Place a Geo-synthetic (silt fence material) fabric into the excavated site to cover the bottom and sides. The fabric ensures that the stone does not become mixed with the sub soil (dirt) underneath.
- Back fill the site with dot approved road base granite (Not granite dust). Rake it around with shovels and back side of a yard rake (not teeth down). You do not want to separate the larger stones from the sand.
- Compact every 2” of lift (not once its all in place). Use a vibratory plate compactor (hand tamps don’t do as well). Get your base compacted & graded so there is no more than 3/8” surface variance (dips). Use a 10’ “straight” board to check your surface.
- Lay down “screed rails” (1” pipes) to help establish an exact 1” bed of bedding sand. Fill the area to the top of the pipes, then slide your board along the rails to pull away excess sand. Do not compact this sand.
- Place pavers either starting along your longest straight edge or in the middle of the patio. When you have placed all the whole pavers, it’s time to cut the edge pieces. Overlaying the pattern, then cutting the pavers in place will be the fastest and easiest. Do not install any cut pieces less than one third of the original paver size. Back into the pattern and cut a few in half so the edge has larger pieces. Small pieces will cause the edge to fail. A concrete saw equipped with a diamond blade is best. A wet cut tile saw will work too. Change the water frequently.
- Place edging along the edge of the patio. Use non galvanized steel 3/8”x10” spikes and rigid (where possible) abs (plastic) edging. Without proper edge restraints, a patio will fail. Troweled concrete or wood is not proper.
- Once the edging is installed and all the edge pieces are cut and installed, it’s time to compact again. (yes, before the joint sand goes down.) Always start on the perimeter and work toward the center. Now run north south then east west.
- You need to find proper “washed” sand that has all the dust removed and has angular (not round) particles. Do not buy regular play sand or masonry sand. Spend the money on the proper sand. In fact spring for the “polymeric sand,” this kind of sand is proper for the application PLUS it has a binding polymer (glue) component to it. Which ever way you go, spread your sand on a dry surface. Sweep it out evenly until the surface is covered with a thin layer (no mounds). Now its time to run the compactor one more time. Start on the perimeter, and check your joints for proper fill. Slip a business card into the slot. If it sinks more than ¼” , add more sand. Once the joints are full and compacted, your done. If you used Polymeric sand, follow the directions on the bag carefully to wet & wait, then wet & wait several times. You are trying to penetrate the sand with water to at least 1 ½” deep. One heavy application of water will simply wash all the polymer out of the sand or even remove sand too. Be careful.
A 20 x 15 patio excavated 4”deep plus the extra 6” of perimeter for edging will generate over 4 tons of soil to haul away or relocate on site. That same patio will require around 4 tons of Dot approved road base (4”), 1 ton of bedding sand (washed granite) and over 3 tons of pavers.
There are several resources out there that may suggest different, more simplistic methods of installation. Be careful. Consider this- What does Home Depot or Lowes sell? Materials? What does an installer sell? A job they know they can guarantee and stake their reputation on, right? Who do you think knows more about the install process?
Why am I sharing the knowledge? I believe pavers are a good product when installed correctly and I know that the person that is willing to tackle this type of project is not my target customer anyway. A few unfinished projects may come my way for trying to help, but more importantly, a few paver projects might just get installed correctly and raise the public opinion of pavers as a whole. Good luck and have fun.
If you still want to see some how to videos, follow the links below to Lowes sponsored videos on Youtube.
You can also visit www.youtube.com to find many do-it-yourself instructional videos.
Follow this link to a Brick patio installation guide supplied by the (BIA) brick industry association.