Brick Accents 2 - Patios Brick Accents 2 - Patios
An important factor in your enjoyment of the patio will be sitting. The patio must be kept drained and dry to prevent algae growth. You will need to provide enough slope (about 1/4 inch per foot) to allow for proper drainage. If you are bricking over a concrete slab patio which has insufficient slope, this problem can be corrected with a leveling bed of mortar. A sunny location also helps keep the patio dry.
Concrete slabs for outdoor use are normally poured about 4 inches thick over an equally thick base of gravel. Place welded wire mesh (6" x 6", 10 x 10 gauge is recommended) over the gravel to strengthen the concrete slab against cracking as temperature changes occur. Use 2 x 4s for forming material properly set with stakes and props so that the wet concrete won't push them outward. The top of the 2 x 4s should be set to the desired grade with the 2 inch or 4 inch hand level to establish the slope of the slab. Finish the concrete with a rough wooden float to achieve a coarse texture to which the mortar bed can bond well.
Before you begin to lay the brick, check the slope of the concrete slab and set the string line and string level to adjust for good drainage. It's a good idea to perform a "dry run" first - lay the brick alone, without the mortar, on the slab. Allow for 1/2 inch to 3/8 inch mortar joints between the brick, depending on the size of the brick units. At this point you will see whether or not any individual brick must be cut. With practice, you will be able to cut the brick units after laying them, but in the beginning it is better to have a few already cut and on hand before the mortar is mixed.
Lay the brick in a 1/2 inch mortar bed, using shoved joints. When the brick is in place and the mortar is "thumbprint" hard, press each joint to compact it with a mason's pointing tool.
Wet the patio down with a light spray from a garden hose (a pressured spray will harm the mortar joints). This will loosen mortar crumbs and allow the masonry to cure properly. If the patio still doesn't look clean, sprinkle sand on any mortar smears that remain and sweep it away gently with a broom, taking care not to dig into the mortar joints.
If the mortar smears still remain, wait a week (until the masonry cures) and clean with a solution of one part muriatic acid to nine parts water, mixed in a plastic bucket. Wear rubber gloves and protective clothing when you handle this solution. Wet the patio first to keep the acid solution from soaking thoroughly, and flush completely with a pressure spray from your garden hose.
Courtesy of the Brick Institute of America