The standard brick is eight inches long, 3 ¾ inches wide, and 2 ½ inches thick. When estimating the number of bricks needed for a project, plan on five bricks per square foot. If placing bricks in a complex pattern that will generally require more cutting, such as herringbone, then allow six bricks per square foot.
Some common brick patio and walkway patterns include:
Brick Pattern Illustrations
Often made from concrete, pavers are produced in a wide variety of sizes and patterns. Pavers are generally about two to four inches thick, four inches wide and around eight inches long, depending on the style. Some come in half-sizes also, which is useful in creating more complex patterns. Pavers may be round, square, hexagonal, octagonal, or diamond shaped. Some are made from plain concrete while others are finished with exposed aggregate, stained, or surface patterns. Many pavers have an interlocking design that forms a particularly stable surface. Commonly placed without mortar, interlocking pavers are laid quickly and easily once the base has been prepared. Like brick-on-sand, pavers installed without being mortared in place must be held in place with a rigid perimeter border.
Depending on where you live, saltillos may also be known as Mexican pavers or terra cotta patio pavers. Usually about 12 inches square, they are commonly made in Mexico where, like sun-dried adobe bricks, they have been used for centuries. All saltillos are not the same thickness and they may have irregular surfaces, indicative of the hand-made quality. It's not unusual to find cat or dog prints on them, which are part of their charm.
Saltillos are normally not glazed. They can be sealed, but it is not essential to do so. If you do seal them, let the saltillos dry thoroughly to see if any efflorescence, which are mineral salts, appears on the surface. If it does, wipe the surface clean and then apply a sealer for the look you want. Sealer choices include clear, semi-gloss, or wet-look gloss
All patios and walkways must have some type of base to keep them from shifting, sinking, and becoming uneven. The base is divided into three categories: flexible, semi-rigid, and rigid. Flexible bases include sand and crushed gravel. Asphalt is a semi-rigid base; concrete is a rigid base. What base you need depends on how you plan to finish the patio or walkway.
If you plan to lay your bricks, pavers or flagstone in mortar, they must be placed on a concrete slab. Any other base will shift or move, which in turn will cause the mortar to crack and the surface material to become loose, which is hazardous to walk on.
Asphalt should be used as a base only when it is preexisting and difficult to remove. It is a semi-rigid surface and is marginal for mortared material. If you live where it gets exceptionally hot in the summer, the asphalt may become soft, allowing the surface material to move and crack. An asphalt surface, however, will serve well as a brick-on-sand base.
Packed sand is an excellent base for brick or thick pavers that will not be mortared in place. Once the sand is packed and leveled, the bricks or pavers are laid tightly against each other and then dry masonry sand is swept over the surface. The sand grains work their way into each crevice and lock the patio material in place, much like tiny shims. For such patios, however, it is essential to have rigid borders around the entire patio. Without such borders, sand will leak away on the edges, bricks will move, and the patio will start to disintegrate. The borders can be brick, concrete, wood, prefabricated aluminum borders, or even earth if the top of the patio is flush with the ground or lawn.
Crushed gravel is an excellent patio or walkway surface by itself. Like sand, however, crushed gravel must have rigid borders to contain it. Crushed gravel, however, is not a sufficiently firm base for mortared stone or brick.
If you plan to have a contractor pour a concrete slab as part of your patio, all the steps involved are listed below so you can familiarize yourself in advance.
First the site is graded level and, if necessary, excavated.
If the slab will be located against or close to the house, ditches containing gravel and flexible drain lines to carry away downspout water should be installed under the slab before it is poured.
Concrete forms, usually 2-by-4 inch boards for a 4-inch-thick slab, are placed around the perimeter, leveled, and braced with stakes. For curves, bender boards are used.
A base of several inches of gravel or crushed rock is placed in the slab area, leveled, and then compacted. Mechanical compactors can be rented.
For larger patios, expansion joints are installed to help keep the concrete from cracking. These joints may be strips of redwood, pressure treated boards, or butyl rubber. The tops are placed flush with the surface of the finished slab.
Wire mesh or iron reinforcing bars (rebar) are placed in the slab area to help prevent the concrete from cracking. The wire or bars are supported off the ground so they will stay in the middle of the concrete during the pour.
Concrete is generally brought to the site in a ready-mix truck. If the patio area is not accessible, then the concrete is pumped to the site by means of a separate pumper and hose.
As the concrete is poured, it is initially spread by shovel and worked to eliminate air bubbles.
The concrete is then screeded, or leveled, by pulling a long board back and forth across the fresh concrete. The ends of the screed rest on the forms.
The final step is to bull float the slab. This involves pushing and pulling a long-handled metal float back and forth across the surface to smooth it and bring water in the concrete to the surface.
How a slab is finished depends on its ultimate use. If it is going to be covered with brick or stone, the slab needs no more finishing after it is bull floated. To give a slab a non-slip surface, a long handled patio broom is dragged over the surface to lightly score it. The technique is generally known as a broom finish. The patio may also be marked in a mock-flagstone pattern with the edge of a grouting tool. A very smooth surface, as often seen in a garage, can be put on with hand trowels, but this is not advisable on patios because it is slippery when wet. If the slab is to be colored, then dry dye is sprinkled over it while the surface water sheen is still evident and then smoothed in. The dye can also be put in the original mix.
Control joints, which are one-inch-deep grooves across the surface, are put in with a special hand trowel. If the concrete subsequently cracks from settling or other causes, the cracks will follow these grooves rather than occur haphazardly. For sidewalks, control joints are usually placed every three feet. Patios may use control joints or more numerous expansion joints.