How to Install Larger Paver Patio Over Smaller Existing Concrete Patio
If you currently have a concrete patio, but want a larger paver patio that provides more space and opportunity to incorporate some of your favorite ideas to enhance your outdoor living, we can help.
To be efficient and cost effective, we want to lay your new pavers over top of your existing patio and extend them to match your new design, but first you will want to verify that your existing concrete patio is sufficient for this application. Your existing patio MUST; be smooth, contain no large cracks, no evidence of scaling or spalling, must slope away from your home and must be at least the thickness of your paver below your entrance threshold.
If your existing concrete patio meets all of this criteria, you are ready to roll.
Clean concrete patio. Clean your existing concrete patio from all dirt and debris. It may be necessary to grind any bumps or ridges flat with surface.
How to excavate for paver patio. Lay out the new design of your paver patio using marking paint. Begin excavating the soil to a depth of approximately 7' below the existing concrete patio. This will allow for 6" of a compacted gravel base plus 1" bedding sand. Excavate 8-10" outside the layout marking lines to allow for grave base overlay (see section view at bottom of page).
Installing the gravel base for paver patio. After excavation is completed and all the loose soil is removed, begin installing the crushed limestone with dust gravel base(from dust to 1 1/4" crushed limestone). Spread the gravel evenly throughout the excavated area, compacting the it in 2" lifts with a vibratory plate compactor. Continue adding gravel and compacting the gravel base until it reaches 3/4" of the top of the existing concrete patio.
Installing bedding sand for paver patio. Using 1" diameter pipe approximately 10' long, lay the pipe directly onto the gravel base as show in the diagram to the left. We recommend using 1" galvanized electric conduit pipe because of it's expensive cost. Begin spreading enough coarse sand to cover the pipe, in between the pipe and a couple of feet on each side of each pipe.
With an 8' long 2 x 4, begin screeding the sand. It may be necessary to fill in any voids with additional sand and re-screed to achieve a uniform layer of bedding sand.
It is necessary to install the bedding sand approximately 3/16" above the concrete. This will allow the pavers installed over the gravel base to seat down into the bedding sand when compacted later on in the installation.
Installing a border around paver patio. Your paver patio will be more aesthetically pleasing if you install a border course. The border course that follows the concrete perimeter of your new design are the only pavers necessary to bond to the existing concrete. Use a quality professional masonry adhesive for this application.
Start laying the border course along your home, butting the pavers against the building and bonding them generously to your existing concrete patio. Continue laying the border course of pavers along the perimeter of your patio.
Installing the field pavers. After the adhesive bonding the border course completely dries, you can begin laying the field pavers. Start the pattern in one corner and work your way across to the opposite corner. More than likely, you will need to cut pavers along the opposite sides.
Installing the joint sand to paver patio. Once all your pavers are laid, you are ready spread sand into the paver joints. Note: The pavers will probably be wobbly over the existing concrete patio prior to installing the joint sand. Sweep the sand across the pavers allowing it to fall into the paver joints. With additional sand still on the pavers begin running the vibratory plate over the pavers. This will help vibrate sand into the joints and seat the pavers laid over the gravel base seat into the bedding sand. Once the joints are filled with sand and pavers are properly seated, sweep the additional sand from the paver patio.
Note: We recommend using a professional grade polymeric sand for your joints. This will help bond the pavers laterally and keep weeds from germinating between the joints. Be sure to follow the manufacturer's instructions for the polymeric sand installation.
Enjoy your new patio!
- Tags: How-To's
- Steve Combs