Standing water on a patio can cause several issues besides being unsightly. This water will cause staining on the surface of the patio and likely carry with it dirt and debris that will build up in that area over time. In the winter this water can freeze and cause slipping hazards.
There are ways to remedy this for your patio, but does require some labor to complete for a paver patio and a lot more labor for a concrete patio.
Standing Water on Patio
There is likely one reason why there is standing water on your patio. That is because there is a low spot in that area where that water is pooling. This could be due to the way it was installed or the area has settled.
If your paver or concrete patio has always pooled water in that specific area, then you likely had an improper installation of that concrete or pavers. Slope is incredibly important and we install our projects at a minimum of 1% (1/8″ per foot) to a maximum of 2% (1/4″ per foot) slope to ensure that water runs off from those areas, away from the foundation of the house and crucial areas, and towards a grass area.
This can be difficult if there are multiple areas that require you slope your pavement away from. For example, if you need to slope away from the house foundation and away from a pool you have multiple slopes on that project to move the water away from each of these. This can be tricky and if installed improperly there can be some areas that trap water because they are the lowest point of that patio.
If your patio has only recently started pooling water, this is because an area has settled. The main reason an area has settled is due to improper compaction. Compaction is required on the subsoil to ensure you build your project on top of and through the base material. Not compacting or installing an improper base depth can lead to areas settling. This is usually most frequently along the foundation of a house. That is because this area is excavated during the building of a home’s foundation and then backfilled without proper compaction by the homebuilder. This causes an area along the foundation to settle slowly over time. Building a patio on top of this without the proper care of compaction (and sometimes even with compacting for your patio) will cause that area to settle along with your patio.
An alternative problem to all of this would be water pooling because a patio is sloped towards a hard vertical surface instead of a drain or soft space such as grass. This is just improper design in the installation of that space. To remedy this problem, the patio would need to be lifted and re-done to slope towards the proper space or to install a surface drain and sent towards somewhere on the property where that water can drain to. This usually means removing parts of the patio, installing the surface drain, along with trenching for a pipe towards that drainage area.
How to Stop Water Pooling on Paver Patio
Pooling water on a paver patio is typically a fairly easy fix. It requires you to remove those pavers in the affected area along with a small section of pavers beyond those affected pavers. You will likely need to clean and scrape the sides of those pavers where the jointing compound has stuck to them. You can then add some base material and compact if you feel that is required to lift that section up significantly. You can however install up to 1.5 inches in total of bedding layer (concrete sand or HPB / 1/4″ clean chip) to build that area up.
You will want to match the level to the surrounding pavers and ensure an appropriate slope away from foundations and other structures you do not want water against. It is helpful to work your way levelling and laying around the existing pavers matching the slope one-by-one. Once the pavers are laid, you can install a jointing compound into the joints and the project is complete. Use a level to double check that the patio has an appropriate slope and that you did not lift that section too high causing another area that is now the low spot and would pool water.
How to Stop Water Pooling on Concrete Patio
Pooling water on a concrete patio is much more difficult to fix compared to a paver patio. Pavers can be lifted, re-leveled, and re-laid to fix a sinking problem. However, if concrete was installed improperly which may be causing the pooling issue or if it has settled over time then there it is more difficult to fix.
Instead of joints like pavers have, concrete has control joints cut into the concrete after curing. These joints are designed to control the cracking of the concrete. No matter what, concrete is going to crack. Over a large area without control joints, that concrete will crack in areas that experience stress from ground movement. In climates that experience freeze-thaw cycles, this ground movement is inevitable through these cycles with heaving during freezing and sinking during thawing. Control joints are strategically placed to ensure the cracking occurs through those control joints and not through the surface of the concrete.
Typically if water is pooling it is because one of these segments of concrete from one control joint to another has settled more than the surrounding segments. In this case there are two options to fix the pooling. You can tear out the existing segment and repour the concrete. The problem with this option is that the new concrete will look different from the other segments. That is because the older concrete may have weathered, but also because concrete does not always cure the exact same color. A lot of this depends on the aggregate and environmental factors which cannot be controlled outside.
The other option to fixing the pooling of water on a concrete patio is to have the segment hydraulically lifted. This requires holes to be drilled into the concrete in specific areas and having a foam mixture pumped into these holes that expands and pushes the segment upwards to ensure that the slope is consistent with the surrounding segments. The problem with this solution is that you will always have those holes drilled into your concrete. They can be patched, but that patch will still stand out compared to the concrete.