Why Water Is Coming Up Through Your Basement Floor—and How to Fix It

Discover how water may be entering your home and how to fix the problem.

Close up of water flooding on parquet floor in a house
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Basement flooding is a common problem that many homeowners need to deal with before it can lead to mold and mildew growth, rot, and further water damage. There are many reasons why water may be seeping up through the basement floor and several steps that you can take to help stop the problem, or at least manage the issue until it can be permanently fixed by a professional.

Water seepage issues can do long-term damage to the foundation, break down the infrastructure of the home, and create air quality issues inside the home. To prevent these problems from growing beyond repair, it's necessary to fix water seepage issues quickly. Learn more about why water is coming up through your basement floor and how to fix it.

Reasons for Water Seeping Through the Floor

There are several common reasons for water seeping up through your basement floor, including backed up or collapsed drains, leaking pipes or appliances, a cracked foundation, clogged gutters, and poor drainage.

Backed-Up or Collapsed Drains

Drain lines run from the various water fixtures throughout your home to a central drain pipe that exits through the foundation, carrying waste and wastewater to the municipal wastewater system or to a septic tank if you are not connected to a municipal system. If the drain lines become clogged, the waste and wastewater in the drains can back up into the house through the drains, which can lead to flooding.

Cracks in the drain line can also cause wastewater to seep up through the basement floor. Similarly, if the drain pipe running under the home collapses, the waste from the home will accumulate in the soil and come up through the floor into the basement or crawlspace.

Leaking Pipes or Appliances

Similar to the drain line that runs throughout the home, water pipes also travel through the walls and floors of the home to carry water from a well or municipal water supply to the water fixtures and appliances throughout the home. A leak in a water pipe will continue to run until it is fixed or the source of the water is shut down. This can cause significant damage over time. Leaks can come from the pipes that travel to fixtures and appliances, or they can come from the actual fixtures or appliances.

If you spot water on the ground in the basement, inspect the hot water tank, the washer, the dishwasher, fridge, and freezer to make sure that they are not leaking. Next, check the pipes in the basement for leaks. The water typically enters the home underground, so if there is a break in the main water line, then it can seep into the soil and up through the floor of the home. Extreme condensation can sometimes give the impression that the pipes are leaking.

Condensation forms when the water in the pipes is significantly colder than the air ouside the pipes. The air comes in contact with the cold pipe, causing the water vapor in the air to condense on the cold metal. You can resolve most condensation issues by insulating the water pipes.

Cracked Foundation

The exterior of your home is supposed to be waterproofed in order to prevent rainwater, meltwater, and groundwater from leaking into the house and flooding the basement. However, if the concrete foundation has developed cracks in the walls or floor, then exterior pressure can force water in the surrounding soil through the cracks and into the home. If cracks in the foundation are the cause of the water in your basement, then water seepage likely occurs during heavy rain or when the snow melts and soaks into the ground.

Clogged Gutters

Another factor that contributes to water seepage and basement flooding is the gutter system. Gutters are designed to collect and carry water away from the base of the home so that it doesn't soak into the soil. However, when the gutter system is clogged, the water cannot flow through the troughs along the roof of the house and cannot drain through the downspouts.

The result is water pouring over the sides of the gutters wherever possible. Concrete is a porous material, so even if it doesn't currently have cracks, if the hydrostatic pressure on the outside of the home is great enough, then the water from the saturated soil can be forced through the concrete and into the home.

Poor Drainage

The gutter system is made to carry water away from the home, but if the yard is sloped towards the home, then even if the water flows unhindered through the gutter system, it can still end up running back towards the home. Hydrostatic pressure forces the water through the concrete walls and floor, resulting in regular flooding during heavy rain and while snow is melting. If you have a raised floor in the basement, you may not even notice this issue until it begins to erode the concrete and create cracks in the foundation.

Take These Steps to Stop Water Seepage

DIYers and hands-on homeowners can take action to prevent water from seeping into the home, or at least manage the situation until a professional can complete a more permanent repair.

  • Backed-up drains may be able to be cleared with a drain snake or drain auger that can break up the clog. However, if the drains have collapsed, then you need to contact a plumber immediately to have new drain lines installed. Continued use of the wastewater system with collapsed or leaking drains is not advised.
  • Leaking pipes or appliances can often be fixed by a DIYer with plumbing experience. Locate the leak in the system and shut down the water to the leaking appliance or fixture. If a pipe is leaking, shut down the main water line to stop the flow of water through the pipe. Replacing worn out washers can resolve leaks in appliances, and either soldering or compression plumbing fittings can be used to repair leaking pipes. Just keep in mind that if you have never worked on plumbing before, it's a better choice to contact an experienced plumber or technician.
  • Cracks in the foundation can be patched with hydraulic cement to keep water out of your home. You can also use polyurethane caulk, though it isn't as effective. If cracks have just started to develop then this is a great method for controlling them, but if the foundation has several large cracks, then it's recommended to contact a foundation repair specialist to resolve the problem.
  • Clogged gutters is a relatively easy problem to fix. Simply set and stick to a regular cleaning schedule, so you know that the gutters have been inspected and cleaned at least once per month. Also, make it a priority to inspect and clean the gutters after a severe storm because debris from nearby trees has likely blown into the gutter system.
  • Poor drainage isn't quite as simple to fix, but it is still a problem that most DIYers can tackle. You will need to improve the grade of the yard in order to help water flow away from the home. To do this, it's recommended to rent a backhoe or a similar machine to quickly dig up and level the yard. This is a long process, but taking the time to do it properly will pay off when your basement no longer floods.