Enhance the look of your area by installing concrete over paver slabs
Few things elevate your outdoor entertainment space more than a beautiful paver patio, but if you currently have an unsightly concrete slab, your dream of installing pavers might seem unattainable without major renovations. Fortunately, if you know how to lay pavers on concrete, you can get the job done without demolishing the existing slab–or digging up your entire yard. In this guide, we’ll explain how to install pavers over concrete to save you time, money, and the frustration of a destroyed lawn.
Before you dive in, it’s a good idea to calculate how many pavers you need. Doing so can save you time and trips to your local landscape or home improvement store.
Start by measuring the length and width of your patio in feet and multiply the two numbers. Then, measure the length and width of your pavers in inches and multiply. Divide this second number by 144 to convert to square feet, and then divide your original number by this number. This will give you the number of pavers you should need to complete your project. Add 10% to that number to account for breaks.
You also need to make sure that you have space for the thickness of the pavers on top of your existing slab. Pay particular attention to columns and the space under exterior doors and siding. If the pavers won’t fit, you might need thinner pavers, or you may need to call in a professional to remove the slab before installing the pavers.
First, prepare your existing concrete to ensure it’s level and adhesive can be applied to it.
Start by using your level to make sure the entire surface is relatively flat. Your slab should slope away from your home’s foundation in all directions to direct runoff toward your yard–not your house. The ideal slope is one inch for every eight feet.
Next, look for cracks or unevenness on the surface. You might need to treat the cracks or address the underlying issue, depending on the size of the gap.
Hairline cracks that haven’t widened or become uneven shouldn’t be an issue.
Fill in cracks that are over 1/8-inch wide with polymer-based filler.
If the crack is uneven across the gap, consider calling in a professional to complete concrete leveling and address the root of the problem.
Finally, clean the concrete to ensure the adhesive sticks.
When installing pavers over a concrete slab, start with your border. This will require careful planning to ensure your pavers fit inside the border. Once you know they will fit, you can start laying down the border pavers.
Use a polyurethane-based construction adhesive to adhere your border pavers in place.
Check that each border paver sits at the same height above the slab.
Use your rubber mallet to make adjustments as you work, and to ensure each paver sits perfectly flat.
Let the adhesive cure.
Landscaping fabric will help contain the leveling sand you’ll use in Step 4.
Lay down strips of the fabric over the entire slab.
Use your utility knife to cut the fabric to size, making sure that there are no gaps and that the edges run about halfway up the paver borders and about an inch up your foundation where your patio meets your home.
Cut around columns carefully, and make sure you have a slight overlap at all four corners of the column base.
Now that your landscape fabric is in place, it’s time to place the leveling sand over the area. Use your deck broom to move the sand over the landscape fabric, being careful to get an even coating.
To get a perfectly flat or level surface, you can use a screed board; however, since you’re only putting down a thin layer, you can get away with eyeballing it and using your deck broom. Leveling sand is primarily used to protect your pavers from moisture from below when installed over a level concrete slab.
Work from the inside out so that you don’t trap yourself into a corner, and then must walk on the sand and redo portions of your work. Also, be careful not to move any of the sand under the landscape fabric.
Finally, it’s time for you to lay your paving stones. Since you did all of the prep work, this step should go relatively quickly.
Begin in a corner and work your way toward the opposite corner.
When laying pavers, don’t shift them into place, as this will create unevenness in the sand below. Instead, position them and drop them into place. Interlocking pavers cost a bit more, but they can make this process a little faster.
Use a rubber mallet to make adjustments, as needed, and to maintain a level surface.
When you get to the edge where you prefer partial pavers to appear (if applicable), use a circular saw or an angle grinder with a masonry blade to cut the pavers to the correct size. You can also use a chisel and hammer if you don’t have power tools or aren’t comfortable using them. Make sure you wear a respirator and safety goggles when cutting pavers.
Next, dump some polymeric sand on your new paver patio and sweep it around the surface. The goal is to fill all of the gaps between the pavers with the sand to prevent them from shifting around over time.
Wet the patio with a hose to help the sand settle into place and activate the silica, which is the binding agent that keeps everything together.
You can seal your pavers to protect them from dirt, moisture, and stains. To do this, add your paver sealer to your garden sprayer and dilute according to the manufacturer’s directions. Clean the pavers before sealing them, and then spray the sealer over the surface. This will cut down on the amount of paver maintenance over time.
You may want to wait two to three months before applying the sealer to your pavers. From the time of installation to the time of sealer application, efflorescence may occur–which is when moisture trapped inside the pavers makes its way out. Waiting for this to occur could lead to a cleaner appearance of your pavers. Consult with a paver installer near you to see if your pavers would benefit from waiting to have the sealer applied.
Laying pavers is a complicated job that is also time-consuming and labor-intensive. Laying pavers over an existing concrete slab is a bit easier because you don’t have to worry about leveling gravel and paver base, but the work can still be challenging, even for experienced DIYers.
If you’re comfortable taking on the work yourself, you could save an average of between $1,000 and $2,000, as the materials are much less expensive than the labor.
If you’re uncomfortable tackling the job yourself, don’t have much DIY experience, or aren’t sure if you can get the professional appearance you’re looking for, you can always reach out to a local paver installer to get the work done.
If you’re installing pavers over an existing concrete slab, you don’t need to affix the majority of the pavers, but you should use a polyurethane-based adhesive on the border pavers. Polyurethane will expand and contract with temperature changes, which will help keep the pavers firmly in place throughout the year. It’s also strong enough to stand up to foot traffic. You’ll use polymeric sand between the non-border pavers to keep them in place and prevent shifting.
You should place a layer of thick landscaping fabric directly over the concrete slab and then a thin layer of leveling sand over that to protect the pavers from moisture. For border pavers, you should plan on locking them in place with polyurethane adhesive. This will prevent them from shifting under foot traffic.
It’s far more labor-intensive and expensive to demolish a concrete slab before laying down pavers. You’ll need a professional to break up and haul away the concrete, excavate underneath, bring in paver base or crushed gravel, and then level the area with leveling sand before laying the pavers. A new paver patio will cost around $1,000 to $2,000, which is more than laying pavers over a concrete patio, and takes longer to complete.
