When your basement floods after heavy rain, melting snow, or a burst pipe, your home becomes susceptible to water damage, and repair expenses can begin to pile up. Having a plan in place and taking a proactive approach to repairing your basement can help to mitigate stress. Read our guide below to learn how to clean, dry, and repair a flooded basement as advised by the United States Environmental Protection Agency’s flood cleanup guide. We dive into safety precautions, water-removal techniques, and when to call in the professionals for help.

---

Step 1: Immediate Response to Repair a Flooded Basement

Follow the steps below once you realize your basement has flooded. Wait until a storm is over before you safely begin.

Mitigate Immediate Safety Hazards

1. Check for a gas leak: Check for potential hazards before you enter your basement. If you smell gas, evacuate the house immediately and then call your gas company and the fire department from a safe location. 
2. Assess for structure damage: If you see cracks in the foundation, sagging ceilings, bowing walls, or other signs of instability, the basement might be unsafe to enter. Call a structural engineer to assess the area before you proceed.
3. Shut off the power: Find your main electrical panel and shut off the breakers that control power to the basement to avoid the risk of shock. If the box looks wet, use a plastic or wooden stick to flip the breakers. Never touch the electrical panel while you’re standing in water. If you’re not certain which breakers are correct, or if the panel is damaged, call a qualified electrician.

Prepare to Take a Closer Look

1. Wear proper gear: Wear rubber boots and gloves to keep your skin dry and minimize the possibility of electric shock. Wear a face mask to protect your lungs from mold or contaminants.
2. Look for the water source: Identify the cause of the flood. If you find there’s a plumbing issue, shut off the main water supply to the house. You can find this valve near your water meter or hot water heater. It could be in the basement, crawl space, utility room, or in a panel that’s buried in your yard near the curb.
3. Identify the type of floodwater. Water that comes from a burst pipe or leaked rainwater is the cleanest and safest to deal with. Gray water, which comes from sources such as washing machines or bathtubs, is usually safe to address, but you’ll need to be cautious. Catastrophic storm flooding and sewage backups create highly toxic black water, which you should hire a professional to address.

Enter the Basement

1. Walk carefully: The floor may be slippery, and there may be snakes or other small animals hiding in debris. Use a stick to make sure the area in front of you is clear.
2. Unclog the floor drainage system: Make sure your basement floor drains aren’t blocked or clogged.
3. Open doors and windows: Open basement windows and doors to increase airflow, as improved ventilation will prevent the growth of mold and mildew.
4. Unplug appliances: Remove all plugs from outlets while the electricity is off. Then unscrew the faceplates of outlets and switches that have gotten wet. Carefully remove any mud or other debris you find.
5. Call your insurance company: Your homeowners insurance or flood insurance policy may cover the damage depending on the cause of the flood. Call your insurer to find out.

---

Step 2: Inspection and Assessment of the Flooded Basement

Inspect the entire basement once conditions are safe to determine the extent of the damage and identify any hazards. This information will help you to file an insurance claim and plan safe repairs. Look for the variables below.

• Appliances and utilities: Hire a qualified electrician or technician to inspect any appliances or utility systems that the floodwater soaked, such as your washing machine, dryer, or water heater.
• Hidden water: Investigate any signs of hidden water damage, such as water stains, warped surfaces, or dripping sounds. Damage may be lurking behind walls or under flooring.
• Mold and mildew: Look for signs of mold growth and be aware of musty odors. Mold can develop quickly, so stay vigilant.
• Structural concerns: Carefully examine walls, floors, and ceilings. Look for cracks, shifting, bulging, or anything that wasn’t evident before the flood. If you notice significant structural concerns, call a structural engineer or qualified contractor immediately for a safety assessment.

Take detailed photos and videos of the basement and damaged areas as you go. Make a list of all your damaged belongings that includes descriptions, brands, model numbers, approximate age, and estimated replacement costs. You will need this evidence to support your insurance claim.

---

Step 3: Water Removal from Basement

The amount of water in your basement will dictate how you should approach the water-removal process. Consider the methods below, and prioritize safety, especially if there’s water near any electrical sources.

Minor Flooding

If the standing water is less than 6 inches high, use a wet/dry vacuum or mop and bucket to remove it. If there’s mud or silt, shovel it out before it dries and hardens.

Moderate Flooding

Rent or install a sump pump to remove water from moderate flooding slowly. Pumping out water too quickly can cause structural damage. The Federal Emergency Management Agency recommends pumping out only 1 foot of water every 24 hours to prevent walls from collapsing. Pump out a foot of water, then mark the water level and wait overnight. If the water level rises, the area around your home is still flooded, and you’ll need to wait to continue pumping. If the water level is the same or lower, pump out a foot of water per day.

The best sump pumps cost anywhere from $58 to $520. Some models feature battery-powered backups that you can use during a power outage. Don’t use a plug-in pump if the water reaches any electrical outlets.

Major Flooding 

If the water level is more than a few feet high, or there’s any visible structural damage, hire a professional water-removal company. Professionals have heavy-duty water extractors that can get the job done easily, and your homeowners insurance policy may cover professional water removal.

---

Step 4: Drying and Dehumidifying the Basement

Once you’ve removed standing water from the basement, you need to dry and dehumidify the area. Professional services use commercial-grade air movers and dehumidifiers, and consult moisture meters to determine how long to keep the equipment running. Some professionals may also use air scrubbers to remove harmful particles from the air.

You can approach drying and dehumidifying as a do-it-yourself project by moving soaked furniture, rugs, boxes, and other items out of the basement to allow better airflow. This will also prevent further moisture build-up. Then use a combination of HVAC, fans, and dehumidifiers to dry the space. Follow the dos and don’ts below to dry your basement:

• DO aim for a humidity level that’s between 30% and 50%.
• DO open windows and doors to maximize cross-ventilation.
• DO use fans to improve airflow. Direct them toward damp areas, walls, and corners. Renting high-powered commercial fans can speed up the drying process.
• DO use a portable generator to power fans and dehumidifiers if your power’s out or your electrical system is unsafe.
• DO run your home’s air conditioning if it’s working and uncontaminated by floodwater. It will pull moisture from the air.

• DON’T run fans if there’s visible mold. These may spread mold spores.
• DON’T forget to empty dehumidifier reservoirs frequently. Set them up to drain continuously
• DON’T run a generator inside, even in your garage. Keep it outdoors and at least 20 feet away from the home to prevent carbon monoxide poisoning.
• DON’T rely on air conditioning alone. It assists in the drying process, but it’s not designed for heavy-duty dehumidification.
• DON’T assume materials such as wood are dry because they feel dry to the touch. Buy a moisture meter to make sure wood’s water content is 15% or less before assuming dehumidification is finished.

The chance of mildew and mold growth increases after 48 hours, so act as quickly as you can. Pay special attention to corners, the areas behind appliances, and other spaces that have become obstructed. Drying time can take as little as a few hours to up to six weeks depending on the severity of the problem and the external humidity.

---

Step 5: Cleaning and Disinfecting the Basement

Clean and disinfect the basement and everything in it to prevent mold growth and other potential health hazards. Remember the distinction between clean water, gray water, and black water.

You must throw away any porous materials that the flood contaminated with sewage water or floodwater, which has bacteria and other contaminants. This includes carpets and upholstered furniture. Take any soft items that clean or gray water have damaged to a professional cleaner. You must replace porous building materials such as drywall no matter which type of floodwater it has encountered.

Clean hard surfaces in the basement thoroughly once you have cleaned and dried it out. Mop concrete floors and walls with a bleach solution of 3/4 cup of bleach per gallon of water. Open windows and run fans while disinfecting with bleach. Wear gloves and a mask, too, and rinse surfaces afterward.

Seek professional help if you’re dealing with black water contamination or catastrophic flooding. Consider hiring a professional, too, to handle extensive gray water damage or significant mud deposits. If you believe your basement walls have lead paint or your floors have asbestos tile, contact a professional hazardous material abatement team.

---

Step 6: Repair Damages in the Basement

After you finish removing the water and cleaning, you should determine the damage repair you can complete yourself, and the repair for which you should hire professionals. Water-damaged outlets, wiring, switches, or any electrical components within the flooded area call for the services of a qualified electrician, for example.

Consider tackling the jobs below, yourself, as part of a DIY project:

Mold Remediation

Mold is a likely and serious consequence of flooding. Properly treating mold is important so that you and your family can breathe safely. It’s safe to tackle mold remediation as a DIY project if the affected area is 10 square feet or smaller, according to the EPA. Otherwise, you should hire a professional.  

Remember that visible mold is usually only a small part of the problem. A musty smell in your basement calls for a thorough inspection and remediation, even if you don’t immediately see mold. People with asthma, allergies, or other health sensitivities should consider hiring professionals no matter the size of the mold patch.

Floor Repairs

Cement basement floors are easy to clean, disinfect, and dry after a flood. Consider sealing them to prevent future moisture issues, but wait until floors are completely dry. To confirm a floor is dry, seal a small sheet of plastic to the concrete with tape and check it after 24 hours. If there’s condensation on the underside of the plastic, the concrete needs longer to dry. 

You’ll probably need to replace carpet or any other flood-damaged floor material that warps or retains moisture. These materials are difficult to properly clean and may grow mold. Homeowners can usually replace carpet, tile, or vinyl themselves, but subfloor repair can be more complex.

Drywall Repairs

You must replace basement drywall that remains soft, warped, or discolored after completely drying because it’s structurally compromised and poses the risk of mold growth. The EPA recommends removing drywall to a height of 4 feet if the flood level was lower than 2.5 feet. If the water level was higher than that, you need to remove the drywall to a level of 8 feet, or at the ceiling junction. It’s usually more cost effective to remove entire sheets of drywall than try to patch the lower portion of the wall

Replacing drywall can be a DIY project if you’re comfortable demoing the impacted walls and installing replacement pieces. It can be challenging to match the wall texture and work around electrical or plumbing elements, though. You may also want to hire a professional to install encapsulation materials such as vapor barriers.

Ceiling Repairs

You must always replace water-damaged ceiling drywall, even if it has dried, as it loses strength and poses the risk of mold growth. Ceiling repairs are be more complex than wall repairs, and you should call a professional if you notice any signs of damage to the joists or subfloor.

---

Step 7: Future Basement Flooding Prevention

Take the steps to prevent basement water issues, especially if the area is at high risk of flooding again. Consider the ideas below.

• Encapsulation: Fully waterproofing your basement by encapsulating your foundation is an expensive but highly effective and permanent option.
• Exterior drainage improvements: Prevent water damage from the exterior of your home by installing gutters, downspouts, and landscaping that grades away from the house. 
• Interior drainage improvements: If your basement floor requires substantial repair, consider installing a French drain to keep standing water from pooling inside.
• Leak detection system: Place water detection devices near any appliances that use water, such as a water heater or washing machine. The device will sound an alarm to notify you to shut off the water when there’s a leak.
• Sump pumps: Install an electric sump pump to remove water as it comes in. Add a battery-powered or water-powered backup in case power goes out during a storm.
• Waterproof paint: You can apply a waterproof coating to concrete or cement surfaces in your basement or crawl space to minimize future damage. Paint and sealant offer minor protection only, though. They will not prevent flooding or structural damage.

Check out the video below to learn more about sump pumps and leak detection devices:

---

DIY vs. Professional Basement Flood Repair

You can approach some repair jobs with DIY techniques, but calling a professional is frequently the safest and most efficient route. Professionals have the proper equipment for removing water, sanitizing the area, and removing mold or mildew. 

When To Hire a Professional

Hiring a professional is especially important if you notice any of the following:

• Electrical damage: If your electrical system is unsafe, call a professional to inspect it.
• Extensive flooding: Significant amounts of water or flooding that come from multiple sources can overwhelm you and increase the risk of improper drying.
• Sewage contamination: Black water poses serious health risks, and you should contact professional remediation specialists that have specialized training and equipment.
• Structural damage: Major foundation cracks, sagging walls, or warped framing call for professional assessment.
• You feel overwhelmed or uncertain: If the scope of the damage feels daunting, or you have any doubts about your ability to thoroughly dry, sanitize, and repair the area, call a professional.

How To Choose a Reputable Restoration Company

Ask your home insurance company to recommend local vendors. If you need to choose your own contractor, look for the following:

• Check the Better Business Bureau website for ratings and accreditations.
• Look for affiliations with bodies such as the Institute of Inspection Cleaning and Restoration Certification.
• Make sure professionals offer guarantees, and are bonded, licensed, and insured.
• Obtain detailed written quotes from at least three different local providers before you make your choice.
• Review testimonials and seek out client feedback.

---

FAQ About Flooded Basement Repair

How do I know if my homeowner’s insurance covers flood damage?

Homeowners insurance typically doesn’t cover flood damage that’s caused by storms or other weather events. Insurance may cover plumbing issues as long as they weren’t caused by neglect or deferred maintenance. 

How do you get moisture out of a basement after a flood?

The best way to get moisture out of a basement after a flood is to open all the windows and doors, pump out the water, and run fans and dehumidifiers. Starting this process quickly reduces the risk of mold and mildew growth. 

What is a sump pump?

A sump pump is a small piece of equipment that monitors water levels and pumps water out. The tools has a pipe that leads water from inside the basement to outside the house.

Is it safe to go in a flooded basement?

Going into a flooded basement is safe if you turn off the electricity and make sure the water level is low. Wear protective clothing, such as rubber boots, gloves, and a face mask, to protect yourself from unsanitary water and potential mold. 

Does a flooded basement cause mold?

Yes, a flooded basement can easily cause mold. Mold colonies can begin to grow within 24–48 hours of flooding.

To share feedback or ask a question about this article, send a note to our team at reviews@thisoldhousereviews.com.