Effective Patio Drainage for Paver Patios

A custom brick paver patio being laid.

Even though it may not be the first thing on your mind when you go to plan your new paver patio, drainage will greatly impact your ability to enjoy your new living area. Drainage is the natural or artificial movement of surface and sub-surface water.

Without the proper setup, water can roll back on your foundation, causing damaging erosion. Standing water can breed insects and ruin your landscaping, and it can cause your paver patio to subside and throw the entire area out of level. There are a number of ways you can effectively drain the water from your patio.


A sand base for a paver patio

The base of your patio provides drainage. Unless you have mortared each paver, there is a certain amount of sand in between each piece. Water will percolate through this sand until it reaches the base. Depending on whether you properly laid a base of gravel or sand, the water may pool under your pavers, or it may wash out the sand if not properly compacted. This will cause your pavers to sink. Therefore, your first line of defense is to properly lay the base when installing the patio.


One of the simplest ways to drain water away is to slope the base of your patio. The natural pull of gravity will drain water down the slight slope you have created. To effectively move the water, you will need to grade the base 1/4-inch for each linear foot of your patio surface.


A stack of PVC pipes

Some soils hold water, but other soils drain quickly. If water will stand, consider installing a patio drain that ties into a drain pipe. Run the pipe under the pavers and out to an area that will handle the outflow. Do not drain your water directly into a storm drain or ditch as this water can be full of contaminants that will end up directly in your local streams and lakes.

Even if you move it off the patio and away from the house, you may still have to move the water elsewhere. You can install a French drain at the edge of the patio (downslope) to do this. Make your own from a PVC pipe with holes in the bottom, buried under the gravel that allows water to sink to the pipe once it hits. The French drain then carries the water to where you want it.


You can also construct a dry well to handle excess water. This is a hole or barrel filled with gravel and sand that transfers water into the subsoil by holding it until it can percolate naturally. A dry well is a good choice to receive the water from a French drain or could be put in under your patio as part of the base. This is only recommended if you know it can handle the water flow. If, however, you can not-- move the water away to another area of your yard.

If you have already installed your patio, and it turns into a pond with each rainfall, you should probably just bite the bullet and start all over. Take notes about the water flow in the area, noting problem zones, you must take the density of the topsoil, and subsoil into consideration as well if you have to solve a potentially serious flooding issue.


Hunker down on both heels and look at the lay of the land closely with an eye towards the sloping contours of the land, and consider how water will move down along them or pool there and back up. Regardless of the size of the area involved, you can see and read how the land around the project drains naturally, and how it drains by design to gutters, or storm drains.

Determine how to get it to flow away on its own as easily as possible and if you aren't sure how to do it you can call an expert to look at it and advise you on how best to proceed. You can re-plan your patio utilizing multiple tools to move water safely and effectively by doing your homework at DIY before you set out to do it yourself.