How to Clean a Flooded Basement

We’ve added a new smart water sensor, the D-Link DCH-S1621KT Whole Home Smart Wi-Fi Water Leak Sensor Kit.

No one is immune to the calamitous force of water, no matter how much people try to control its various entry and exit points throughout a home. Bathtubs overflow. Water heaters leak. Snow and rain … sometimes just find a way in. And no matter how it gets in, all that water can be deleterious to your home.

Everyone’s home is different, but the steps outlined here provide a good baseline for most dwellings.

If you can remove the water safely, you should start the process as soon as possible to minimize your losses and prevent future damage.

To get the most from an insurance claim, take videos, not just photos, of both the damage and the water source.

Standing water that contains raw sewage is usually best handled by a professional. The same goes for floodwater.

We talked to a range of experts in the flood-remediation world to gather the information we wish we’d known in the immediate aftermath of our own flood experiences. With the following advice, we can help you minimize the damage. We also offer the prep steps and basic info that anyone who owns, rents, or generally lives inside a building should know—just in case.

For this guide I interviewed several experts in the world of flood remediation, including Darren Hudema, who used to write standards for IICRC, the ANSI-affiliated Institute of Inspection, Cleaning, and Restoration Certification, and is currently an approved IICRC instructor and the director of training and technical services for PuroClean, a property emergency services franchise. Among other courses, Hudema regularly floods a test house (video) to teach technicians remediation techniques and applied structural drying. I also spoke with Nelson Rivera, a firefighter who owns and operates three PuroClean companies throughout New Jersey; Pete Marrero, a senior restoration manager for BluSky Restoration Contractors (formerly J.C. Restoration, a second-generation, family-owned restoration business); and Justin Bowe, a contractor with 20 years of experience and the owner of Bowe Construction, a company I’ve hired in the past to work on my own home.

I also gained insight from several Wirecutter staffers who have dealt with water damage and flood remediation. Particularly helpful was senior software engineer Eric Dulcet, who was in the process of cleaning a flooded garage (the result of excessive snow melt) by using a shovel to push water out as I wrote this article. I also interviewed editor-in-chief Ben Frumin, who drained a couple of inches of water out of his basement after a rainstorm in 2021. Editor Jon Chase and senior staff writer Rachel Cericola weighed in with their expertise regarding smart-home devices that can help prevent flooding.

As the editor of Wirecutter’s emergency preparedness guides, I’ve researched how to protect a home from a hurricane as well as how to clean up after one, and senior editor Harry Sawyers got his hands dirty with some firsthand testing using a wet-dry vac to clean up hundreds of gallons of water.

Just about anyone who lives in some sort of a building should consider preparing for a flood. So many situations can lead to some indoor inundation that just about any homeowner or landlord, and even most renters, should make general plans for where a flood might occur and what they’ll do if anything urgent comes up.

In writing our guide to smart water-leak detectors, we learned from the Insurance Information Institute that about one in 50 insured homes filed a claim for water damage in recent years. The stats go only to 2019, so that number doesn’t even take into consideration large-scale freeze events that have occurred over the past couple of years, or damage from natural flooding disasters. Still, per the most recent report, water damage and freezing accounted for the second-highest number of homeowner insurance claims overall, after wind and hail damage.

No two cases of water damage are exactly the same, but by focusing our research on a common flooding situation that the experts we spoke with often encounter—an unfinished or partially finished basement that takes on an inch or less of standing water—we found plenty of practical immediate remediation tactics that you can apply to similar water emergencies in the home, whether you’re a confident DIYer or a novice. This know-how is important because, as BluSky’s Pete Marrero told us, “Reaction time matters when you have water damage.”

As with all of our emergency preparedness guides, we recommend that you absorb the information here before you find yourself in the midst of a crisis. The best way to deal with water damage is knowing how to handle it ahead of time.

In flood remediation, water is divided into three categories:

When it comes to black water from, say, a sewage-pipe backup, we recommend going with a professional rather than trying to tackle the situation yourself. (Just make sure your professional is licensed, insured, and approved by your own insurance.) “The average homeowner doesn’t have the correct PPE to work in that environment,” said PuroClean franchise owner Nelson Rivera. “The procedures and tactics taken for black water are completely different than clean water.”

Pete Marrero agreed but said that a small amount of black water from sewage-pipe flooding is likely okay to take on yourself with the proper PPE: rubber boots, N95 masks, safety goggles, and rubber gloves. Be sure to completely cover any open wounds and to thoroughly wash yourself and any surfaces the black water touches. “You would absolutely want to call in a professional, or at least consult with one, if the exposed area is greater than 3 square feet,” he said. But use common sense, too: If even some small pooling smells or looks particularly foul, play it safe and call an expert.

Water damage from flooding caused by natural disasters such as a storm surge or floodwaters that leak into a home should always be considered hazardous black water, and the Centers for Disease Control and Prevention recommends keeping out of it entirely if you can, since there’s no way of knowing what the water has been contaminated with. If your home has taken on floodwater, ideally you’d be able to wait for a professional. But that isn’t always possible, and when we ran that scenario past the experts we spoke to, they said to follow the steps we outline here to prevent damage and the potential for microbial growth but to make sure you’re wearing all the same PPE (as described above) for sewage water.

Understanding the mechanics of your home is crucial. Many of the experts we spoke to remarked on the number of people they’ve come across who are unfamiliar with even the most basic inner workings of their house. Ideally you’ve been able to familiarize yourself with the location of your home’s water shutoff and breaker panel before the moment of crisis.

With water damage, you should know how to turn off your home’s electricity, although as Nelson Rivera pointed out, “Usually the breakers trip when there’s an issue.” But if you have to pass through standing water to get to your breaker box, and the electricity is still on, call a professional. “It can be like stepping into something that, you know, changes your hairstyle,” PuroClean’s Darren Hudema said. “It’s better to just stay out, without putting yourself in harm's way.”

If your home uses well water, the shutoff valve is usually on your pump tank, but for municipal water it can be just about anywhere. If you don’t know where yours is, and you’re not currently dealing with water damage in your home, search it out or have a plumber come by to show you. Consider marking it or loosely tying a ribbon around the pipe so that everyone in your household has a quick visual reminder in the event of an emergency.

If you have to wade into water to reach the water-shutoff valve, watch your step—heightened anxiety and a sense of urgency can cause some folks to rush right in and injure themselves. “Slip-and-falls are real,” Rivera said. Remain aware of the possibility throughout your entire cleanup process.

Flooded basements resulting from some kind of water runoff entering the home, whether it’s from a heavy rainstorm or melting snow, are events that we’ve seen catch new homeowners off guard, especially within the first few years of their moving in. Not all flooding of this nature is even manageable for a single homeowner, but with the right upgrades you may be able to clean up after, and even prevent, minor sporadic events. You can find full books on remediation strategies; Green Building Advisor is an excellent resource. We explore the topic a bit in our guide to dehumidifiers, and This Old House has a good guide to wet-basement solutions.

Once you’ve eliminated the water source, start to record the scope of the damage, including the source of the water, for your homeowner insurance claim. Most plans should cover damage caused by, say, a burst pipe, but the amount you’ll get is contingent on how well you record your losses, and Rivera recommends being as thorough as possible. “Do a full video walkthrough,” he said. “Not just photos.”

Watch your step while cleaning and documenting. Heightened anxiety and a sense of urgency can cause some folks to rush right in and injure themselves.

Losses from flood damage caused by a natural disaster are not typically covered through standard homeowner insurance. The Federal Emergency Management Agency set up the National Flood Insurance Program (PDF), a policy that anyone with property in one of the 23,000 participating NFIP communities can purchase. Though the NFIP is managed by FEMA, you obtain a policy through a normal insurance provider. A FEMA spokesperson told us via email that homes and businesses in high-risk flood areas with mortgages from government-backed lenders are required to have flood insurance. But even if you do have the right kind of insurance to cover damage from an environmental loss such as a hurricane, payouts are increasingly difficult to get.

After you’ve removed the water, continue to take plenty of photos and videos of the damage for your insurance claim as you clean and dry. If you pick up a box and a soggy bottom causes the contents to spill out all over the floor, take a picture. The more thorough you are, the more likely you are to get money back. “Insurance will only pay when you can verify,” Rivera said. Instead of claiming, say, a box of Christmas ornaments, he recommends itemizing every ornament in a spreadsheet with a photo of the box’s contents. “I always instruct my customers, never throw anything away until you’re paid for it.” We’d make an exception for any stinky soaked carpet, but only after you’ve photographed it.

Once you’ve completed your initial documentation, you should get the water out of your home as fast as possible. Sometimes all that might require is a mop and a bucket, or you can get creative. Wirecutter senior software engineer Eric Dulcet used a shovel to slide water out of his flooded garage and onto his driveway, and my sister used a rectangular garbage can instead of a bucket to scoop pooling water from her basement as it flooded during a storm. “By placing one of the flat sides against the floor, I was able to pick up much more water than I could with my round bucket,” she told me.

Wirecutter editor-in-chief Ben Frumin was able to empty his basement of rainwater after a heavy storm by hammering open a rusted-shut sewer drain pipe in the floor that a plumber friend advised him to look for. Not all homes have such drains, and his experience is a great example of why it’s important to know your house.

If you don’t have an outlet like a sewer drain pipe or a sump pump in your basement, and you’re looking at large pools of water or a floor surface that’s completely covered with water, a wet-dry vac, also called a shop vacuum, is your best bet. “That’s ideal,” Rivera said. “Unfortunately a lot of people don’t have one.” We highly recommend owning a wet-dry vac because they’re handy for all kinds of messes, and we like the Ridgid 12 Gal. NXT Wet Dry Vac HD1200. These machines aren’t meant for cleaning up deep pooling, like a foot of standing water, but in our scenario of an inch or two, the Ridgid shop vacuum worked great.

We also tested additional accessories for that Ridgid model that are specifically designed for water removal, and we found several that proved essential in sucking up and removing large amounts of liquid.

The Ridgid HD1200 is capable, powerful, and equipped with a water-removal nozzle, but we found that a few additional accessories make cleaning up liquid much easier.

The Ridgid HD1200 comes with a 7-foot hose, but swapping it out for this 20-foot-long option helps you clean a much larger surface area without having to move the vacuum.

Adding a foam filter when clearing large volumes of water helps protect the Ridgid vacuum’s motor by catching debris.

May be out of stock

This add-on pump sucks water out of the Ridgid HD1200 through a standard garden hose so you don’t have to keep lifting and emptying the vacuum.

The 12-gallon Ridgid HD1200 is the shop vacuum that Wirecutter senior staff writer Doug Mahoney saw the most on job sites throughout his 10-year construction career, and it’s the model he has personally used the most. I have one, too, and I find its powerful suction extremely handy for all sorts of chores, everything from cleaning radiators to clearing sawdust from a garage. But I’ve never had to use it for water cleanup, so senior editor Harry Sawyers tested the Ridgid HD1200 and a few add-on accessories designed for water removal—a longer hose, a foam filter, and an attachable pump—on a disaster of his own making that stood in for our flooded floor: his secondhand 15-foot-diameter pool, which had been gathering leaves in the water left below its drainage hole for several weeks.

At its deepest, the pool held only about 2 inches of water, but as Harry quickly discovered, “a small amount of water over a large area is a lot more than it looks like.” He went into his cleanup project thinking that both the longer hose and the pump would be optional tools, but he found them both essential for the task. We strongly recommend using the foam filter to protect the Ridgid vacuum’s motor against debris in the water. Equally important is reinserting the original filter once you’re done. As Doug said, “It’s a nightmare when someone takes the filter out to wet-vac, then forgets to put it back in. The next day, someone goes to use the vac, and it blasts dust all over the place.”

Before trying the external-attachment accessories, Harry worked using only the shop vac’s out-of-the box attachments to test how easy it was to suck water up and then empty the drum himself. The 12-gallon Ridgid HD1200 got so heavy (a single gallon of water weighs around 8.3 pounds) that once it was full the sides buckled as he lifted it. If you’re using a wet-dry vac without a pump, give yourself a lighter lift by emptying the drum frequently and before it’s full.

The Ridgid HD1200 comes with a 7-foot hose; swapping it out for the 20-foot Ridgid Dual-Flex Tug-A-Long almost triples that length. The add-on hose’s extra reach is useful for large messes because the Ridgid Quick Connect Pump, which attaches to the bottom of the HD1200 via its built-in drain pump, can’t be submerged without taking damage. “You have to be able to move your vac well clear of the flood zone and still be able to place the long hose into the mess,” Harry explained. The longer hose can also help in relation to your distance from your power source: The pump’s power cord is 15 feet long, and the manufacturer advises against using an extension cord.

The Quick Connect Pump allows you to fill the vac with water via either the included hose or the accessory hose and then expel the liquid through a standard garden hose that leads to an outlet such as a window, slop sink, or sump pump. (The product listing on Home Depot’s site contains an animated visual of the process.) Harry’s pool was filled with debris, and the same could happen with a basement flood. “You’ll want to strain first if you can, or a bit of time will be lost unjamming the wet surface head of the hose,” Harry said, suggesting that a pool net or a spare window screen could work to skim the water’s surface.

The biggest overall limitation you might face when sucking water out with a shop vac is that you need to have a dedicated, level, dry spot to perch the machine, and that space may not be available a lot of the time in a flooding scenario.

Harry also noted that the plastic threads around the pump connector felt like one of the weakest points on an otherwise high-quality product. A separate accessory that’s included with the pump—an all-plastic shutoff valve that controls the water output from the pump—is a convenient touch, but we suspect it won’t last as long as the vac itself. And when you’re relocating the vac, you need to be careful not to bump the pump on anything—a wall, a stair rail, or other basement objects—or you could potentially damage the plastic threads holding it in place and create a leaky connection.

As long as you don’t encounter issues while making the connections and have a stable surface for the Ridgid HD1200, the wet-dry vac and its suite of accessories work great for easily moving hundreds of gallons of water, Harry found. “It’s so quickly exhausting to try to relocate any amount of water more than a few gallons, and the amount of effort saved here is immense,” he said. And as machines go, the Ridgid HD1200 has personality: “It’s like working with an animal. You just fling its snout there and let it go at it. The vac sounds like it’s gasping a bit when the bucket gets full. You can get into a nice rhythm with this whole operation, where you’re essentially flipping switches and flinging the hose around but not really doing a ton of work.”

Once the water is out of your basement, you’ll likely be left with a lot of dirty surfaces. It might be tempting to clean them with bleach as an extra step against potential microbial growth, but many experts don’t think that’s necessary. “I like dish soap and water,” Marrero said. “It’s really all you need.”

Microbial growth, including mold, can start anywhere between 24 and 72 hours after a flooding event, so drying your space early is crucial. “You want to always assume that there’s potential for mold growth,” Rivera said. “Always assume the worst, because if you don’t and you ignore it, six months down the line you might have a huge mold issue that could have been avoided if you just properly dried out whatever was wet.”

Setting up fans to increase the drying process feels instinctual, but if you own a dehumidifier, that’s a much better option. A fan will speed up evaporation, but as Rivera pointed out, what that does is “increase the relative humidity in the air.” And that means you wind up with lingering water that still needs to be removed.

Justin Bowe pointed out another disadvantage of fans: “They’re blowing dust around.” Fans are absolutely better than nothing, but your best bet is a good dehumidifier. If fans are your only option, make sure to open your windows and confirm that the humidity of the outside air isn’t high.

Keep your dehumidifier and/or fan on until everything is dry; many of our experts recommend keeping the appliances on for a full 72 hours just to be safe.

This 50-pint, pump-equipped machine is a great option for pulling moisture from the air in unoccupied areas up to 1,200 square feet.

To help dehumidify a basement after water damage, we recommend the Hisense DH7019KP1WG. In our guide to the best dehumidifiers, we specifically suggest this model for basements because, although it’s louder than other picks, it’s equipped with a pump that’s superior to what we saw on other dehumidifiers we tested thanks to its supple (versus stiff) hose and its user-friendly thumb-operated hose-detachment mechanism. If you have a slop sink, a window, or any other sort of water outlet, you won’t have to worry about constantly emptying this model’s 50-pint bucket. Plus, it’s cheaper than our other picks that can handle a similar amount of space, around 1,200 square feet. (In our tests, it outperformed its own rating of 1,000 square feet.)

If your basement is partially finished and water has made contact with any portion of drywall, make sure that moisture hasn’t gotten inside. “You can have a piece of drywall get wet a hundred times, never be dried properly, and never have a mold issue,” Rivera said. “You can have the same piece of drywall under different conditions get wet one time and have a mold issue.”

A professional will remove the baseboards from any affected area and cut sections of drywall out before positioning fans and dehumidifiers in front of the gaps to dry the insides. If the flooding is light, Marrero recommends that homeowners perform a smaller-scale version of this method. “You carefully detach the baseboard by scoring it with a razor, and pull it back with maybe a spatula or a putty knife,” he said. “You don’t want to do damage to the wall, you want to try to save it as best you can. Once the base trim is off, you can take a screwdriver or the butt of a hammer and put small holes along the baseline where that water damage is.” If you have a drill, you can use that instead to make small holes, and then you can place your fans and/or dehumidifier in front of the open spaces. “Airflow is going to carry through the wall cavity,” Marrero said. “You can always patch and paint the drywall later.” Since you can’t see the inside of the wall, it’s best to play it safe and reattach the baseboard only after 72 hours, since you won’t be able to feel the inside of the wall to tell if it’s dry.

If any part of your basement is carpeted, everyone I spoke with recommended pulling up the carpeting and padding and throwing it away. “Carpet and the padding below acts like a giant sponge,” Rivera said. “For the average homeowner, a shop vac isn’t going to be able to suck that amount of water out. If you have gray padding, or what we call horsehair padding, it’s going to stink. I mean on the first day.”

Dry any possessions that got wet in whatever manner you can; editor-in-chief Ben Frumin was able to take the contents of his basement out into his yard to dry in the sun. Every situation will be different, so all we can say is use common sense and maybe take this water damage as an opportunity to clear out some junk.

The following smart tools detect—and in some cases can stop—leaks and broken pipes before they become disasters.

This D-Link kit has a plug-in Wi-Fi hub with an optional sensor cable, and it can connect with up to 16 battery-powered remote sensors. It responds quickly to potential problems with both a loud siren and fast smartphone alerts.

The quickest, easiest, and least expensive way to protect your home and belongings from water damage is to install one or more smart water-leak detectors. These palm-sized sensors vary in shape, but they all work about the same way: You place them on the ground in a spot where you might experience a leak—around a water heater or clothes washer, for example. If any leaking or flooding occurs, the water should make contact with the sensor, triggering it to send a notification to your phone and set off an alarm. All of the experts we spoke with are fans of leak detectors in general. Rivera likened them to smoke detectors. “You’re alerted right away,” he said. “Then you can shut the water off before it’s running for 20 minutes, hours even.”

In our guide to the best smart water-leak detectors, we recommend the D-Link DCH-S1621KT Whole Home Smart Wi-Fi Water Leak Sensor Kit because it combines the best capabilities our testers have seen available in leak sensors into one bundle. It includes a plug-in hub (and so can be placed only in areas near an electrical outlet), but it also has a removable 19-inch water-sensing cable and a 38-inch extension cord to lengthen that cable’s reach. In addition, the kit comes with a matchbox-sized remote battery-operated sensor that connects wirelessly to the hub from up to 300 feet away. The hub can connect with up to 16 add-on sensors, responds quickly when it senses water or if it loses power, and features a loud siren (94 dB, by our measurements, about the same volume as a lawn mower). The system supports Google Assistant for announcing activity on smart speakers, as well as the web service and app IFTTT (If This Then That) for triggering other smart devices (such as a smart bulb) when it finds a leak. Like every other leak sensor, it has a few quirks, but it’s still the best choice for monitoring more than one spot in a home.

Placement is important, as these sensors work only if water actually makes contact with them. So put sensors in any low spots of the floor where leaking water is likely to pool. And keep in mind that even when a leak detector does its job perfectly, it’s still unable to do anything beyond sending word that there’s a problem. You’ll have a leg up to start taking action, but our next pick takes minimizing damage a big step further.

This option is expensive—but not as much as a flooded basement.

The Phyn Plus is similar to the Flo shutoff valve but a bit cheaper.

May be out of stock

A smart water-shutoff valve will automatically turn your home’s water off for you if the device detects an emergency. The device’s water-flow-sensing abilities trigger an electro-mechanical switch to physically stop your home’s main water supply if it detects an abnormal, ongoing, or particularly intense flow of water, such as from a pipe bursting, but also if your water line is beginning to freeze.

Starting at $500 and going up to $700, these devices are expensive, and a plumber should install them (depending on your home’s setup, the process should take an hour or two). However, many home-insurance companies offer a discount for installing one, as well as a potentially discounted or rebated price, so it’s possible to break even. The Flo by Moen and Phyn Plus shutoff valves are two popular models.

These devices rely on sophisticated AI software to interpret the various types of water flows in your home and to understand your pattern of water use. If your Flo or Phyn device detects a change in water flow or pressure that is consistent with a leak or pipes beginning to freeze, it will send you a smartphone notification and sometimes a suggestion of what the issue might be, such as a running toilet or a faucet that has been left on. Depending on your preferences, you can configure these devices to completely shut off your home’s water supply if the potential leak hasn’t been resolved quickly (with both the Flo and the Phyn, you can opt out of that setting or use the app to turn your water back on at any time).

Because these devices rely on a bit of guesswork and take about a week to “learn” your home, they sometimes get things wrong. For instance, if you are the only person in your household who is away from home and you fail to notice a warning, your home’s water may shut off, stranding someone at home who’s taking a late shower. We’ve also found that these devices can sometimes be over- or under-sensitive. For instance, someone doing a load of laundry or running a hose or taking a bath at an atypical hour might trigger a heart-stopping alert claiming that the house is flooding. Other times, a dripping faucet could go unnoticed for days or weeks because the flow is just too subtle for the sensor to detect it. Still, we’ve concluded that homeowners—not to mention anyone who has a vacation or rental property—should consider these devices for their ability to thwart disasters.

We’ve primarily focused this guide on clean-water damage from a source inside the home, but there are plenty of ways for rainwater and snowmelt to sneak in, too, as Wirecutter’s Eric Dulcet discovered when piles of snow on the outside of his garage melted and seeped through the walls. Since his garage was flush with the driveway outside, he used a shovel to push the water out, and he is now taking measures to make sure snow pileup will be diverted away from the edges of his home in the future. Here are several steps that any homeowner should take to help keep outside water from coming in.

Clear gutters: Keep your gutters, as well as the downspouts, free of debris. Aiming a hose into them can help clear blockage. Add downspout extensions if water drains close to your home’s foundation.

Trim bushes and trees: Keep greenery pruned away from the sides of your home. Cut tree branches at least 5 to 10 feet away from the walls and roof to prevent damage to the house during a storm.

Grade the foundation: Soil should be sloped downward from the sides of your home so that water runs away from it and doesn’t pool. This Old House has a good tutorial video that shows how to create a grade around the foundation with a method that’s particularly helpful if your home is built on a hill. But depending on where in the country you live and the type of house you have, you might have better options for your circumstances. Our best advice is to search out tutorials online that are specific to your case or call a professional.

This article was edited by Harry Sawyers.

Joshua Lyon

Lead Editor

Joshua Lyon is the supervising editor of emergency-preparation and home-improvement topics at Wirecutter. He has written and edited for numerous outlets, including Country Living, Modern Farmer, The New York Times, V and VMAN, Marie Claire, Jane, and Food Network Magazine. He’s also a Lambda Literary Award–nominated author and ghostwriter. Learn more at jklyon.com.

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