Don't let a flood be the downfall of your basement
Causes for basement flooding include faulty pipes, flooding, and your location.
Inspect your basement and the exterior of your home to find the cause.
Installing a drain system, leveling your property, and waterproofing your basement can prevent future flooding.
Work with a licensed plumber to clean up the flood quickly.
Whether your basement has slippery puddles or it's starting to look like an indoor swimming pool, one thing’s for sure: basement flooding is a messy and costly problem. Fortunately, understanding what causes basement flooding and knowing what steps you can take can help mitigate the damage. Follow this ultimate guide on basement flooding causes so that you know what to do when a flood strikes your home.
Knowing what caused your basement to flood is one of the first steps you can take to stop the flooding and prevent damage to your home. Here are some of the most common reasons for basement flooding.
A hydrostatic pressure problem means that the groundwater levels on the outside of your basement have risen above floor level, causing water to leak through small cracks around the concrete floor.
If you've inspected your property and checked for leaks by looking at your water meter only to find that the number isn't changing, you might have a hydrostatic pressure problem. Another telltale sign of a hydrostatic pressure problem is leakage from many different locations around the floor of your basement.
Leaky windows or doors are another possible reason for a flooded basement. A leaky window or door can result from forgetting to shut the window, not repairing cracks or broken glass, deteriorated caulk, or a door in need of new weather stripping.
Plumbing is prone to leaks, from a burst pipe to loose valves and connectors. Shut off the main water valve, jot down the number on your water meter, wait an hour, and then compare the numbers to see if you have a leak causing your flooded basement. Finding a plumbing leak can be tricky, so work with a plumber or trained technician to detect leaks if you can't find them yourself.
If you have groundwater in your basement after a rainstorm, then your house’s location could be the culprit. Location is one of the most common reasons for a flooded basement—especially if you live in any of the following areas:
Bottom of a hill or mountain: Water can collect from snowmelt and rainfall and come racing down the slope—right to your home.
Flood-prone area: Homes near rivers, streams, bays, ponds, or lakes can experience flooding if the body of water rises.
Low-graded lot: If your house is on a low point, the slope may direct water toward rather than away from it.
A sign that you could have a surface water leak is a leak coming from just one wall, though an isolated leak on one side of a wall could also be a sign of a leaky pipe.
If you have foul-smelling odors along with your leak, then there could be a problem with stormwater impacting your city's storm sewer system. If the backup occurs on your property, you’re responsible for fixing the problem, but for off-property city lines, you can get by scot-free. Contact your local municipality for problems beyond the scope of your home's plumbing system to see if they’re responsible for the issue.
Finding the cause of basement flooding can be as easy as finding a needle in a haystack. But with a map of key areas to look for, you can increase your chances of finding out why your basement is leaking faster.
To find a basement leak, check the following areas of your home:
Your basement walls and flooring
The gutter system
Your roof
Cracks in the foundation
Plumbing systems
Your sump pump
Swampy or unusually green spots on your lawn
Puddles around your foundation
Your landscape slope
Windows
Doors
To fix a leaky basement, it’s important to know who to call when there’s water in your basement. You'll want to reach out to your homeowners insurance and then work with a local water restoration company near you to find the best plan of action. Here’s how this process might look, depending on the cause of your flooded basement.
Before you fix a flooded basement, it's a good idea to check with your homeowners insurance to see if your homeowners insurance plan can cover water damage. If it does, then you'll want to document the flooding by writing down when it occurred and taking pictures or videos of the damage. File a claim with your homeowners insurance company before you fix a flooded basement in case insurance covers the repairs under your plan.
Also called an interior weeping tile system, this drainage system is a perforated pipe that goes underground, around the perimeter of your foundation. The perforated pipe lets in water and helps relieve hydrostatic pressure by evenly draining the water around your foundation and steering it away from the home.
If you install an interior perimeter basement drain, then you'll also want to install a sump pump. A sump pump system is a pit that a professional digs beneath your basement to collect water once it reaches a certain level.
When your home doesn't have the correct slope, regrading and releveling around your foundation might be the best way to protect your foundation from future leaks. Your lawn should have a slope of 6 inches for every 10 feet around the foundation of your property. Leveling a yard can be a complex project that requires heavy machinery, so it's best to work with a local landscape grading service to get the best results.
If a broken or clogged pipe is causing your basement to leak, then repairing or replacing the faulty pipe is likely the only way to resolve the issue.
You'll spend anywhere from $500 to $2,800 on the cost of repairing a flooded basement. Small floods fall at the lower end of this price range, while floods with two or more feet of water will cost the most.
After you have stopped your basement from flooding, you may need to invest in water restoration services to prevent mold, clean contaminated surfaces, repair damaged parts of your basement, and seal your basement to prevent future flooding. If you need to invest in these services, you could spend more than $10,000 in total.
Basement floods don't always have to happen. With a proactive basement waterproofing plan, you can help prevent your basement from flooding in the first place. Here are several ways you can prevent a basement from flooding:
Caulking or replacing windows or doors can leak water into your basement during storms or floods. Apply caulk as needed, install secure weather stripping or door seals, and replace faulty windows or doors.
If you don't have a gutter system or your gutters are clogged or misaligned, it's important to keep them in good condition to prevent water from flowing down to your foundation—straight into your basement.
Sump pumps are one of the best ways to prevent a basement from flooding, so ensure you have one installed and keep up with a sump pump maintenance schedule. Your sump pump should be inspected and cleaned yearly to prevent it from failing. Most sump pumps need replacing anywhere from five to 10 years.
A water leak detection system is a water sensor that can alert you to leaks through your phone or an alarm. This monitoring system will track the flow of water through your chosen pipes and send an alert signal if it detects an abnormal flow.
Your home's foundation should sit at a 5 percent slope minimum. If the soil around your foundation has shifted, or gardening has decreased the slope, then leveling your yard to the appropriate incline can prevent water from flowing towards your home.
Inspecting your washer, dishwasher, garbage disposal, heat pump, toilet, and any other appliances in your home with connectors and hoses can help you catch leaks. Set a monthly maintenance plan to keep your appliances up to date.
If your pipes keep leaking, then it might be time to replace them—especially if your metal pipes are over the age of 50 to 80. Traditional PVC pipes have an even shorter lifespan of around 25 to 40 years.
Walking around your property after storms and at least twice a year can help you catch leaks as soon as they arise. For homes in flood-prone areas, you might want to increase your inspections to once every month.
Though it might seem like a leaky roof will only flood your attic, water flows down. When gravity works its magic, water can weasel its way through the walls and ceilings of your home until it reaches your basement.
Learning how to waterproof your basement can help prevent water from entering from the outside. On average, basement waterproofing costs between $2,300 and $7,600 and involves removing water and mold, sealing cracks and gaps, sealing concrete surfaces, and altering your landscape if needed. For maximum protection against basement floods, it’s best to work with a basement waterproofing professional near you.
Foundation waterproofing could be a DIY project, though it isn’t recommended for novices. For this to be a DIY project, you should have knowledge of and be comfortable with:
Installing a dehumidifier
Grading soil
Sealing windows and doors
Gutter systems
Applying waterproof paint
Clearing stairwell drains
If you don’t have this experience or the waterproofing project is more elaborate, requiring tasks such as installing a drainage system, fixing gutters, or sealing large or uneven foundation cracks, we recommend talking to a professional to waterproof your basement. A professional can help identify the source of the leak or flood, diagnose the underlying issue, and come up with a comprehensive waterproofing plan that is appropriate for your home. In addition, professional jobs should come with a basement waterproofing warranty which will give you peace of mind in case of any future issues.
A leaky foundation is one of the biggest causes of basement floods. Be it flooding, lack of yard drainage, or a sewer backup, many visible and hidden culprits can cause your foundation to leak water into your basement. If you're unsure why your basement keeps flooding, work with a professional to inspect your property and stop the flooding for good.
Flooded basements are dangerous—this is extra true when electricity is involved. From electrocution to sewage waste to mold, you're putting your family at risk if you choose to stay in a house with a flooded basement. For this reason, it's best to find alternative housing until you have restored your basement to a healthy and safe environment.
Many basements are prone to flooding, but not all basements flood. And, just because it is common for basements to flood it doesn't mean that you can't take steps to protect your basement from flooding. Maintain your gutter system, check your landscape slope, install a sump pump, and check faulty pipes regularly to help decrease the likelihood of your basement flooding.
It depends on the source of the flood. Some homeowners insurance policies cover certain situations but not others—standard HO-3 policies exclude flooding that occurs as a result of rain, storm surges, sewer backup, and snowmelt. However, they might cover flooding caused by burst pipes, broken appliances, or a localized overflow from a bathtub or sink. It’s always best to read your policy closely to understand what it covers and under what circumstances.
