Laying Brick Patios in Sand
Set bricks or other paving materials in a well-tamped bed of sand and you’ll have a flexible but firm patio surface that will stand up to years of use, even in areas subject to frost. A brick-in-sand patio is an ideal do-it-yourself project. But carrying the bricks and digging, smoothing, and tamping the patio surface involves hard work that will put a strain on your back. Don’t tackle it by yourself; have helpers on hand.
Tools: Round-point shovel, spade, line or water level, hose, carpenter’s level, hammer, brick set, baby sledgehammer, screed, circular saw with masonry blade, broom, rubber mallet.
How Much Bedding? Adequate bedding is essential for a patio to remain smooth and level for years to come. If you live in an area with periods of heavy rain or winters with below-freezing temperatures, a brick-in-sand patio should rest on a bed of 1 to 2 inches of tamped sand that, in turn, rests on 4 to 6 inches of tamped gravel. In dry climates with soils that have a heavy clay, sand, or rock content, a sand base alone may be sufficient. Check with your building department to see what is required in your area.
1. Lay out the site. Use the techniques to lay out the site. Select the style of edging and the brick pattern you want. Use the 3-4-5 method to establish square corners and use a line level or water level to establish the correct slope, about inch per running foot. If your yard already slopes a bit, but not more than 1/2 inch per foot, you can follow its contour so you will not have to fill in and resod the lawn after building the patio.
2. Excavate and tamp. Remove the sod and dig to the correct depth. Remove roots 1 inch in diameter or larger. The paving material should be 1 inch above grade. Dig out the soil for the edging and patio to a depth that leaves room for adequate bedding material. Adjust the surface height by using more or less bedding material. Tamp the ground firmly, especially if you have not reached undisturbed claylike soil.
3. Install the edging. Stretch a mason’s line to serve as a guide for the height and alignment of the edging. For the brick soldiers shown here, place a small amount of sand in the bottom of the excavation and tap the bricks with the handle of your trowel to set them at the height you want. Fill around the sides of each brick with sand as you work. At this point, backfill with just enough soil to keep the bricks from leaning outward.
Preparing the Ground With a Tamper - It is important that the ground under the sand and gravel bed be firm. In most cases, that means tamping each layer. For small areas, you can use a scrap piece of 4x4 or a fence post for tamping. Or, make a tamper from plywood and 2x lumber like the one. Small hand tampers can be rented, also. For large patios, consider renting a vibrating power tamper. It’s a challenge to transport a large vibrating tamper to the work site, but once you get one there, it speeds up the tamping process dramatically.
4. Cover with landscaping fabric. If your bedding is only sand, cover the tamped soil with landscaping fabric before adding the sand. The fabric reduces weed growth, but allows water to filter through into the soil. For a sand and gravel bed, lay the fabric on top of the tamped gravel. Overlap the sheets about 2 inches. Then spread, smooth, and tamp the sand.
5. Screed the sand. Shovel in the sand to roughly the correct height. Dampen it and tamp it down. Draw a straightedge across the sand to smooth it out. For this purpose, make a screed out of a straight 2x4 with a length of 1x4 or 1x6 nailed to it. If the patio is wider than 8 feet, you will need to install temporary supports for screeding. With a helper, work the screed back and forth as you move it sideways to achieve a level surface.
Crown a walk. When screeding a walkway, give it a slight crown, so water will run off easily. Make a screed with a curved cut, as shown. Pull it across the edging or forms as you would with a flat screed.
6. Lay the bricks. Start in one comer and begin laying the bricks or pavers. Set them straight down rather than sliding them into place so as not to disturb the level sand surface. Set each brick snugly against its neighbors and tap each one gently with a rubber mallet or block of wood. Use a level to check for proper slope and to make sure the bricks are all at the same height. If a brick is too low, pick it up, trowel in more sand, and tap it into place until it rests at the correct height.
7. Check for straightness. Every third or fourth course, use a taut string line as a guide to make sure you are laying the bricks in straight lines and at the proper elevation. Do not step or kneel on the bricks as you work: Use a piece of plywood as a kneeler.
8. Cut bricks to fit. To cut a brick or paver by hand, score it all the way around by tapping a brick set with a baby sledgehammer. Place the brick on a bed of sand or loose soil several inches deep and give it a sharp blow with the brick set. For a cleaner-looking cut, use a circular saw with a masonry cutting blade. Be sure to wear gloves and eye protection.
Caution! For Large Jobs, Use a Masonry Cutoff Saw - If you have a lot of bricks to cut, a circular saw may not be up to the job. Cutting will be slow, ana you'll have to change blades frequently. Worst of all, the brick dust and general wear and tear may burn out your saw. Rent a masonry cutoff saw instead. This is a large power miter box, much like the chopsaw used by carpenters, equipped with a long-lasting blade. With it, you can cut crisp lines with ease all day long, which speeds up the job significantly.
9. Fill the joints. Spread a thin layer of fine sand over the patio surface and gently sweep it back and forth so the sand fills the joints. Be especially careful at first not to dislodge the bricks. Once the joints are full of sand, hose off the entire surface with a fine spray to wash away the remaining sand particles. This compacts the sand and forces it into the joints. Repeat this process, sweeping in more sand and spraying, until the sand is level with the top of the bricks.
Filling Joints With the Dry Mortar Method - You can make your patio more permanent by using dry mortar mix rather than plain sand in the joints. For this method, leave 1/2-inch spaces between the bricks when you set them in place. Sweep the dry mortar mix into the joints, remove excess mortar, and sprinkle the surface gently with water until the mix is wet. Repeat the sprinkling process twice at 15-minute intervals to ensure you have enough water in the mortar. The mortar will harden within a few hours and cure in a week. If your ground heaves with the frost, the mortar lines will crack.
Installing a Semicircular Brick Patio
A semicircular patio looks Jr\ complicated, but actually it requires little more skill than installing a rectangular patio. In fact, because only the central core requires cut brick, you may need to cut fewer bricks than you would for other designs. As with all masonry work, have the bricks or pavers delivered close to the site to minimize lifting and hauling.
Tools: Round-point shovel, rake, tamper, mason’s line, rebar, carpenter’s level, hammer, screed, brick set, baby sledgehammer, broom, hose.
Other Options for Curved Edgings - This project uses 1/4 hard-board as a temporary edging for the patio. For a permanent edging, you may be able to find redwood bender board, which is about 1/4 inch thick and 3 1/2 inches wide. Or ask your lumberyard to rip clear 1x4 redwood along its thickness, leaving you with two pieces about 5/16 inch thick. If you soak the redwood in water for a couple of hours, it will bend easily without cracking. Other permanent edgings include steel ribbon, plastic, flagstone, poured concrete, and bricks.
1. Install the edging. Rig up a compass using a stake and a piece of rebar tied to a mason’s line. Using the compass as a guide, and keeping the rebar vertical, pound in stakes evenly spaced about every 2 feet. Excavate to a 4-inch depth, removing all organic material. Set the hardboard edging in place, bending it and leveling it as you go. Attach it to the stakes with screws so it is 1 inch above grade. Check for a smooth curve. Because stakes are difficult to install accurately, you may need to unscrew the edging at some points and use shims to correct the curve.
2. Screed the site. Tamp the soil, then cover the site with landscaping fabric. Fill the area with crushed gravel and sand, or sand alone, until it is 1 to 2 inches below the edging. Rake it as smooth and level as you can. Notch one end of a straight 2x4 screed so that it rides along the edging as you smooth the base. The depth of the notch should equal the thickness of the bricks or pavers. Install a 2x4 pivot base for the screed, taking care to stake it so the top edge of the screed will be level. Screed the sand, tamp it down with a hand or power vibrating tamper, then screed again.
3. Install the bricks or pavers. Start at the outside of the form and lay all the border bricks. Then work inward, completing each course before moving on to the next. Once you’ve laid several courses, use pieces of plywood on the bricks as kneelers; avoid kneeling or standing directly on the bricks. Every few courses, check your work by scribing an arc with your homemade compass. The joints between the bricks or pavers will be slightly pie-shaped and larger at the end nearest the edging. After the bricks are laid, sweep extra-fine sand into the joints, moisten with a mist or fine spray, and sweep in more sand where needed. Remove the hardboard edging and fill in soil firmly around the perimeter.
Caution! Make the Base Firm
■ Take extra care when installing and tamping down the subsurface of your patio. The curved edge of a patio like this one is especially prone to sinking and buckling over the years because it is not held firmly in place. Even the permanent edgings.
■ You may want to dig a little deeper near the perimeter and install some gravel as well as sand. If you use a hand tamper, do a thorough job; take turns with a helper so you don't get tired. The best way to ensure a solid subsurface is to rent a power vibrating tamper.