A common issue, especially in wet climates or low-lying backyards, is puddling and pooling on top of the patio slab. Not only does this make the patio a wet mess, it can lead to damage. This is because the constant moisture exposure weathers the concrete prematurely. It can also make issues like mildew and mold growth more severe. Fortunately, there are options for overcoming puddling problems.
Option #1: Drainage strips
Drainage strips are designed to be fit into a patio. They are made of either strong plastic or rust-resistant metal. Each strip resembles a long, narrow box with a grate on top and open ends. To use, a channel is cut into the concrete that is wide enough to fit the strip. The strip is then inserted in place and secured with concrete caulk. Water will flow through the grate and be routed off the patio at the ends of the strip. The ends can also be attached to a drainage pipe, which further routes the water away from the concrete.
Option #2: Slope system
A slope system requires building the patio on a slight grade so water flows off one end. Then, a perforated drain pipe is buried along the drainage end of the patio. This is then covered with crushed stone to make a French drain. Water will flow off the sloped patio and into the gravel, where it will make its way into the drain pipe. The pipe will then carry the water to an area of the yard that won't be harmed by the run-off.
Option #3: Decorative trench drain
This is one of the more attractive options, but it is best installed at the same time as the patio. When the patio concrete slab is poured, the contractor will install long basins to divide the patio into squares or rectangles. These basins are similar to drainage strips, but without the grate top. Then, decorative bricks are installed over the top of the trench. These bricks are placed and mortared flush with the concrete so that they look like a decorative accent or border between concrete sections.
A small gap is left between each brick, though, which allows water to flow into the drainage trenches. This is then routed out the ends or into an underground drainage pipe. Not only is this method more decorative than a drainage strip, it also can be more durable since bricks are less likely to suffer damage compared to plastic drainage strips.
Contact a patio contractor like one from GaitlinByrd Cement in your area for more ideas on ways that you can manage the moisture on your patio.