A patio makes a great place to relax or socialize, and a paver-surfaced patio provides a decorative way to build a long-lasting addition to your home. Pavers are available in many sizes and colors, and they can be laid in a number of patterns. Some of these include stack-bond, herringbone, running-bond and basket weave. These standard patterns can also be created in a wide number of variations.
Since patios are typically built with a walking surface just a couple of inches higher than the ground, construction of the patio begins with a lot of excavation.
Most paver patios are built with a flexible base instead of a rigid concrete slab. The patio base is made of at least 4 inches of compacted crushed rock. The depth should measure 4 inches after compaction, which means the base begins with a loose bed about 6 inches deep spread evenly across the patio site. In cold climates where ice heaving is a problem, the compacted bed should be deeper, even up to 8 inches. (Vehicular use requires a base between 8 and 12 inches deep). It’s a good idea for the bed of crushed rock to extend 6 to 10 inches beyond the edges of the finished paver surface.
Plan the patio layout by marking it with stakes and a string line. Then measure the
area in square feet to determine the amount of materials needed. Estimate the number of pavers based on the size and shape of the pavers that you’ve chosen. For waste, add 5
percent for uncut laid pavers and 10 percent for pavers that are to be cut. Note that cutting pavers will require a brick saw, but the pavers can often be laid in a pattern that requires no cutting.
You will also need to determine the amount of edging material you’ll need by measuring
the lineal feet of the exposed patio sides.
You have many options for edging material, including retaining wall blocks, staked-down landscape edging, or a concrete berm.
Sand and crushed gravel are measured in cubic yards, and one cubic yard equals 27
cubic feet. Normally, the bed of crushed rock is topped with 1- to 1-1/2 inches of sand. We recommend using concrete sand (rather than masonry sand) because it has a coarse aggregate that resists washing out over time.
To find out the cubic yards needed for every 1 inch of sand bed, multiply the square footage by .00309. To determine the amount of gravel needed for a 4-in. bed, multiply the square footage by .01235.
When calculating your patio dimensions, first determine the finished top surface of the patio and plan in reverse. Most homeowners want the patio surface to be just a couple of inches above the ground, which provides your starting elevation. From that point, measure downward to determine the depth of the digging, based on the thickness of the pavers, sand bed, and crushed rock. Note that for proper drainage, your patio should slope away from the house 1 inch for every 8 feet.
You will need to plan carefully how to manage the delivery and storage of the materials on site. Paver patios are often touted as DIY-friendly projects, but don’t overlook the logistical challenges of moving the materials. Concrete pavers are heavy, and if they aren’t delivered right where you need them, you’ll have to transport them. Iron out these details with your supplier to reduce your labor. Construction of large patios usually requires renting a mini skid-steer and a plate compactor.
Expect to do a lot of digging on this project.
An assortment of digging tools will come in handy.
Breaking Ground
Before digging out the patio, call 811, which is a free nationwide service that will come to your home and mark the underground utility lines to help you avoid a costly accident.
On the project shown, we used a mini skid-steer for the bulk of the excavation, but the job still required a lot of manual labor to define the edges and to fine-tune the grade. A variety of digging tools will come in handy, including a mattock to pierce the ground, plus a variety of spades, shovels, hoes, etc.
We removed a fence panel at the rear of the property and disposed of the excess dirt from the excavation into a wooded area, then replaced the fence panel.
After the site has been graded flat, we used a vibrating plate compactor to tamp down the
soil. Proper compaction is critical to all phases of a patio project. We recommend that you compact the soil, compact the gravel base, and even compact the patio surface to ensure the pavers are firmly set in the base. (Note: At the rental outlet, request a rubber footplate for the plate compactor to prevent damage to the paver surface when compacting it.)
Decide the height of your patio as your starting point, then add up the material layers and work downward to determine your depth of excavation.
A landscape rake with an aluminum head helps to level dirt and gravel.
For best long-term results, tamp down the excavated ground as well as each material layer of the patio. Cover the compacted earth with landscape fabric.
As an extra level of weed protection, we applied landscape fabric over the patio site before construction.
Next, the landscape fabric is covered with crushed rock. Spread the rock evenly on the site before compacting it. A landscape rake can be particularly useful to spread the rock because it has a broad metal head with rigid tines to move the heavy material.
Since the sand bed will be screeded to match the rock bed, it’s important to engineer the patio slope into the crushed rock. We used a string level to keep an eye on the slope
(along with a 2x4, which we used as a gauge to represent the thickness of the
paver surface plus the sand bed.)
Once the rock bed is graded to the right slope, compact it with the plate compactor.
Spread the crushed rock and compact it. We used a line level to ensure we had a slope of 1” per 8’ away from the house. A 2x4 laid on its edge (3-1/2”) served as a makeshift depth gauge to represent the thickness of our pavers (2-1/2” thick) plus the sand bed (1”).
Sand Bed and Pavers
Next, comes the sand bed, which can be screeded perfectly smooth before applying the pavers.
For large patio areas, you might find it easiest to form the sand bed in sections. We used 1-inch PVC pipes to form the sections. The pipes served a dual purpose: (1) as a continuous depth gauge for the sand bed and (2) as the guide-rails for our screed tool.
Our method: Lay the pipes parallel to each other 3 to 4 feet apart and pour the sand between them. Use a hoe or rake to spread the sand roughly throughout the section. Use enough sand that it piles above the pipes. Then, use a screed tool stretched flush across the two pipes to strike off the excess sand and level the 1-inch bed flush with the top edge of the pipes. We used an aluminum straight-edge as a screed tool, but a 2x4 board can also be used—just make sure it is perfectly straight.
Remove the pipe that is nearest to the edge of the patio, fill its indentation with sand, and trowel it level with the surrounding bed.
We then laid pavers over the completed section of sand bed. Begin laying pavers in one corner of the sand bed, carefully adhering to the layout pattern. Use a rubber mallet to set the pavers into the base.
Once the pavers are complete in that section, move to the next area of the patio site and lay the pipe parallel to the one already in place (3 to 4 feet away). Add sand between the pipes and repeat the screed process. Then add the pavers. Work from section to section until you’ve completed the paver installation at the opposite end of the patio.
Once you pull up a pipe, you'll need to fill the void left with sand and level the surface. To help place the sand in the pipe voids, we made an empty bleach bottle into a sand funnel.
Paver pattern and patio shape will determine how many bricks need to be cut. A curved patio will need to have pavers cut to follow the curve of the border. A rectangular patio can avoid those cuts. A basket-weave pattern is ideal because full pavers can be used throughout a square or rectangular shaped patio. Using a running-bond or 90-degree herringbone in rectangular areas will only require half-cuts.
A wet saw (or a brick set) can be used to cut the pavers.
The paver surface should be compacted when complete. The rental store should include a rubber footplate with the compactor which will help prevent any damage to the pavers.
A rubber mallet helps to set the pavers evenly into the sand bed.
Final Phases
The bottom of the pavers should be recessed below grade with their surface just above ground level. The patio edges should be anchored in place to resist movement and retain the interior pavers.
To create edging that will secure the outer patio pavers, we compacted the ground around the patio and then created a berm of fiber-reinforced concrete that ramped against the exposed sides at a 30-degree angle. The berm would eventually get buried and concealed beneath the lawn.
As an edge restraint, we compacted the base around the pavers, then installed a berm made of fiber-reinforced concrete.
Patio edges that remain above ground (to overcome sloped grades) are built over a short, mortared wall (block or stone with the first course below grade). In such a case, the edge pavers should be mortared to the wall as a final course to retain the inner pavers.
Joint sand will interlock the pavers and provide cushion between them to prevent
paver-to-paver contact and chipping. The joints need to be filled completely with sand to function properly and interlock the system. We recommend using polymeric sand, which is a mixture of polymers and calibrated sand that becomes a firm, but flexible, paver joint. Some professionals recommend troweling the sand into the paver joints for the best results. Polymeric sand prevents erosion and washout, and resists weeds, ants and burrowing insects.
These same basic building procedures can be used to construct paver sidewalks and even driveways (built with deeper base material). Note that walkways should be slightly crowned to allow for settling.
Even with proper excavation, sand will often settle in some places, causing a paver to sink out of alignment. However, the modular natural of the construction makes a paver patio relatively easy to maintain, requiring little more than lifting out the bricks and adding sand to level out the spot.
