Whether you’re planning to build a patio, path or driveway, using concrete pavers will provide lasting durability in a variety of styles. Pavers have a similar appearance to brick and cobblestone, but their uniform size makes them easier to install.
Building a project with pavers might be intimidating, but the techniques are not complicated, and the basic steps stay the same no matter what the scale. Doing the work yourself will save you more than half of the cost of hiring a professional installer.
The time a project will take to complete depends on the complexity of the design and the number of helpers you can round up. Our patio took my brother-in-law, Allen Carriere, an experienced landscape builder, and me about 40 hours to complete.
Design
Begin the design process by thinking about what you want the project to accomplish. For example, the steep sloping backyard of our 1925 bungalow was not good for much other than shedding rain away from the house. With a small house and lot like ours, living space is at a premium. Making the backyard more conducive to activity was like adding an extra room.
The most common solution to creating a level area is to build a deck. A deck’s post-and-beam system allows you to easily build above uneven terrain. Deck materials also offer greater design flexibility.
Despite these advantages, a patio better fit our needs. We didn’t want an elevated platform for two reasons: We wanted the new space to blend with the surrounding landscape, and the house had no back door, so we needed ground-level access. We also thought the material choices for patios had a more permanent feel that better suited the brick and stucco of the house.
The downside to building a patio on a site with elevation changes was that we needed to create a level base for the patio. To accomplish this, we added a small retaining wall to contain the patio base.
After you determine the basic structure of your project, think about how it will be used. We planned to use a 48-in.-dia. table with chairs on the patio, so we measured the furniture and determined that we needed at least an 8 x 8-ft. area so that the chairs wouldn’t fall off the patio when pushed away from the table.
Explore different designs. Draw a scale diagram of your yard on graph paper so you can sketch ideas. Working in scale helps prevent future surprises by limiting guesswork (see “Mapping Your Yard’s Future” photo). Don’t limit yourself at this stage — brainstorm as many combinations as you can. Look at brochures, magazines and other homes for inspiration.
Take your best designs to a landscape supply center for input. The salespeople will likely see problems or suggest improvements. They may also know of new materials or techniques you hadn’t considered.
Another option is to consult a landscape designer or architect. For a fee, that person will develop a design that suits your needs. Effectively communicating your tastes to the designer is the key to getting a plan you like. Use sketches and pictures to describe features you like (and more important, ones you don’t).
When you have settled on a basic design, transfer it to the yard by marking the dimensions on the ground. This allows you to see how your design actually fits in the yard and to make additional modifications (photo 1).
Material choices
Visit a landscape material supplier to see which pavers are available in your area (see “Common Paver Styles” photo). Because pavers’ weight makes them impractical to ship, you’ll buy them from a regional manufacturer (see SOURCES).
For our project, we chose a random cobblestone pattern that uses three blended colors and three sizes. The different sizes are set in a 1:1:1 ratio to form the random pattern. Because there is no pattern to follow, cobble-style pavers take longer to lay than a repeating pattern style.
Site preparation
Before breaking ground, call your utility companies to check for buried supply lines. We completed all ground preparation before ordering anything so that the materials would not be in our way as we worked.
We marked the final patio and path dimensions on the ground and established the final elevations of the patio and path with string lines. We used two separate string lines to designate the two slopes. The minimum slope to use on a patio is 1 in. every 10 ft. Our patio slopes away from the house at a rate of about 1 in. every 4 ft., starting at the sidewalk height. The path follows a steeper slope from the patio level down to meet the driveway.
We excavated an area 6 in. beyond the layout lines on all sides and down to a depth of 8 to 10 in. below the patio and path string lines (photo 2). This depth is calculated by adding together the thickness of the paver, sand base and gravel sub-base (photo 3). We then dug a trench around the patio perimeter that is 21 to 23 in. below the patio string line. This depth equals the height of the paver, retaining wall blocks and gravel base. Don’t worry if you dig a bit deeper in some spots; the final grade will be established with the compacted gravel sub-base.
If you are working on a small patio or on level ground, you can probably dig by hand. But if you are doing a larger job or one that involves regrading the terrain, I recommend using a skid steer loader, commonly known as a Bobcat. You can rent one for about $175 a day and learn to operate it, but I recommend hiring an operator to bring in his own loader and do the digging for you (for $50 to $60 an hour). An experienced operator will do a faster, more precise job and limit the damage to the rest of your yard. This is money well spent.
Estimating materials
The three materials that make up a paver project are compactible gravel (Class 5, road base, etc., depending on where you live), coarse sand and pavers. Gravel and sand are ordered by the cubic yard or ton, and pavers are ordered by the square foot. Use your drawing and the equations in “Estimating Materials”. Bring these dimensions to your supplier and he will determine the quantities of each that you will need.
In addition to these standard materials, I ordered retaining wall blocks to support the front edge of the patio. Retaining wall blocks are ordered by the square footage of the wall face. Add 10 to 15 percent to your estimates to account for irregularities and edge cuts that will be made. It is better to finish with extra materials than to pay an additional delivery charge to order more. Another strategy to minimize delivery costs is to order all of your materials to be delivered together.
Piles and pallets
Before you order anything, you must consider how you will manage the tons of materials that will be arriving. The materials should be located as close to the work area as possible. Talk to the supplier about the trucks the company uses and what kind of access will be required. Some suppliers use only large trucks; others bring a small loader that can transport the materials to hard-to-access areas. Shop for the supplier that best meets your needs. Ironing out logistics now will save you time and physical effort later.
Our site is typical of many urban homes. An alley leads to a narrow driveway that a truck can’t back into. The deliveries had to be dropped in the front yard or street and hauled back to the work site using a skid steer loader. Without the loader, we would have had to haul the materials by hand — not a pleasant thought. Leaving materials in the street often requires a permit. If you plan to do this, check your city’s regulations.
Wall and sub-base
Once your materials are on site, thetypical next step is to start laying the sub-base. For our patio, we had to first install a retaining wall.
We spread a layer of soil-stabilization fabric over the wall, patio and path areas. This tough, woven synthetic fabric ties everything together, helping distribute the loads on the patio and the force of the ground’s heaving in cold climates. This fabric is not required, but it is an inexpensive way to help keep the patio flat.
Spread, lightly wet and then hand tamp a 4- to 6-in.-deep bed of compactible gravel (2- to 4-in. at a time) as a base for the wall (photo 4). Our base needed to be 18-3/8 in. below the final patio height, level from side to side and sloped away from the house to match the patio’s grade. Do a precise job of grading. Any time you might save by rushing this step will likely be lost in fine-tuning the bottom course of wall blocks.
We set the bottom course of blocks so that the tops and fronts were flush, making final adjustments by adding gravel underneath or pounding down with a dead-blow mallet (photo 5). After the bottom course was set and level, we backfilled with gravel.
We staggered the vertical seams by starting the second course with a half block. Small wall blocks like the ones we used can be broken with a brick set and 3-pound maul. The top two courses of block were secured with adhesive to help prevent the wall from shifting when the sub-base for the patio was compacted behind the wall (photo 6). Because the wall ended under the patio, I let the last blocks run long and built up the patio sub-base around them.
With the wall now in place, we were ready to lay the patio and path sub-bases. Properly grading and tamping the sub-base is the key to a patio that will stay flat over time. Spread the gravel in 2- to 4-in. layers until you reach the appropriate depth and lightly wet each layer with water. Rent a plate compactor, a 200-pound gas-powered vibrating plate (about $60 a day), to do the tamping. Make at least four passes with the plate compactor, working in perpendicular directions with each pass (photo 7). If you’re not sure whether you have tamped enough, tamp more.
The final grade should have no depressions and must slope away from any structure at a rate of at least 1 in. every 10 ft. The final grade should also be no more than 3 in. below the soil line so that the tops of the pavers will end up slightly above the soil. The final grade for our patio needed to be a specific height for the pavers to be flush with the sidewalk and rest on the top of the wall. We used a 3/4-in. pipe supported by landscape spikes to reach the final grade height (see “Establishing Sub-base Height”).
After tamping, we rolled a 6-ft. length of pipe over all areas to check for high and low spots. We filled in the low areas and scraped away the high areas as necessary and tamped again.
After tamping, the base is stable and safe for walking. If you are expecting heavy rain before finishing the project, cover the base to prevent the fine surface gravel from washing away.
Sand and pavers
To keep the patio or path together, all sides must butt up against a solid feature such as a sidewalk, wall or paver edging (photo 8). In situations where none of these barriers will work, you may need to secure the border pavers with adhesive. For example, the pavers along the front edge of our patio run out over the top of the retaining wall (photo 9), so we had to use adhesive. Allow the adhesive at least 24 hours to set before fitting the field pavers against the border, or soldier course.
Choose the most visible side of the patio to begin laying pavers. We started where the patio met the sidewalk. This way, we could place whole pavers where they would be seen and keep the cuts in less noticeable areas.
The pavers rest on a 1-in. bed of coarse sand. Prepare an area that is small enough for you to reach without being on the sand. Use 3/4-in.-dia. pipes as screed bars to establish a consistent 1-in. depth (photo 10). Then slide the pipes out of the sand, fill in the tracks left by the pipes, and smooth the sand with a trowel or float (photo 11).
Run a string line to establish a straight first row (photo 12). Do not count on existing structures to be straight. Our first row uses a single paver size to create a soldier course. After laying the first row, we began the random cobblestone pattern (photo 13).
Periodically check alignment with a new string line. Depending on the pattern you are laying, small alignment shifts can quickly magnify into big problems. The random pattern we chose is more forgiving than a running-bond pattern would be.
When the first sand bed area is nearly covered, reset the pipes and screed another sand bed. Continue laying full pavers until you get to a curve or the opposite side of the patio. At these points you will need to cut pavers to fit (photos 14, 15).
As you work across the patio, you can gently walk on larger areas that have been paved. If paving takes more than a day, cover the patio with plastic tarps to protect the sand from erosion.
When all of the pavers have been laid, make a couple of passes with the plate compactor directly on the pavers. This noisy but very important step sets the pavers. After tamping, inspect the patio for pavers that are too low, too high or cracked. To fix any of these problems, pull out the offending paver, add or subtract sand and replace the paver.
The final step is to sweep dry sand over the entire patio and tamp it again (photo 16). This locks the pavers together. Repeat this process two or three times until the crevices between the pavers are filled with sand.
You can treat the pavers with a masonry sealer after a few months of use. Sealing is not necessary but does help to bring out the colors of the pavers and protect them from staining.
SOURCES
Hedberg Aggregates
(763) 545-4400, www.shadeslanding.com/hedberg/
Interlocking Concrete Paver Institute
(202) 712-9036, www.icpi.org
Progress Lighting
(864) 599-6000, www.progresslighting.com
Uni-Group USA
www.uni-groupusa.org