Basement Flooding: Tips for Handling and Preventing a Flooded Basement

Water…it’s a wonderful thing in a lake, pool, even a tub. But in a basement? Well, it’s pretty much every homeowner’s worst nightmare. Sadly, basement flooding happens for many different reasons. The good news? There are ways to assess possible basement flooding risks, great tips to prevent them from happening and – should the worst occur – effective ways to deal with water in the basement. The takeaway? An ounce of basement flooding prevention is worth a gallon of cure. 

Causes of basement flooding

It makes sense that basements are at risk of flooding. Think about it: they’re either partially or fully underground which puts them at the mercy of many elements. So before dealing with water in the basement, let’s walk through the most common causes of basement flooding.

Heavy rain/snowmelt

This one seems the most obvious: tons of rain and rapidly melting snow need a place to go and it’s underground where every basement, finished or not, is located. Rain and snow can cause flooding as they can build up moisture, leading to eventual cracks in the walls where water can seep in and leaks can form.

Drainage tile failure

Drain tiles are a type of plastic pipe laid beneath the ground around the home’s foundation. When properly installed, they direct water downhill and away from the house using the force of gravity or into a collection pit where a sump pump pumps it away from the house. If the tiles aren’t correctly installed or begin to fail, basement flooding will happen, noticeably during wet weather. 

Improper sealing

A home’s foundation and its basement drain tiles need to be properly sealed. On the inside, that means filling in any holes or cracks in the basement’s ceiling, walls or floors with special sealants, such as hydraulic cement, to make them watertight. On the outside, it means excavating around the perimeter, removing old weeping tiles, and applying layers of waterproof membranes. 

Improperly installed downspouts

A better name for “downspouts” might be “away” spouts, as any water that isn’t directed away from the house will drain into it and may cause basement flooding. Downspouts need to be in place (i.e. not missing or broken) to prevent water from pooling near the house where it can seep into the basement and cause cracks in the foundation. Ensure they extend at least six feet away from the home and drain water away from the home. 

Cracked foundation

Cracks in the home’s foundation can be caused by many things: tree roots pushing through; settlement (which means the soil beneath the home is not well compacted so the house can shift significantly); drainage issues that allow water to damage the foundation; and more. Whatever the cause, foundation cracks will lead to basement flooding.

Sewage backup

Most sewage backup is caused by basic clogs in the home’s pipes (often attributed to cooking grease and oil build up), but backup can also be caused by old drains that were built with clay pipes, which break down with time and crack.

Failed sump pump

When a sump pump fails (usually from a stuck switch) all the excess water that it’s supposed to drain away from the house will start to accumulate at the lowest point in your home, i.e. the basement. 

Broken, cracked, or clogged pipes

Pipes move water around the house and away from the house so any kind of impediment within a pipe will result in backup that leads to flooding.

Hot water tank failure

This big tank of hot water is one of the most beneficial appliances in a home, but, like most things, it can break down and lead to basement flooding. It’s a good idea to have a hot water tank inspected yearly by a licensed professional.

What to do after a basement flood

Despite all best efforts, basement flooding can still happen. When it does, it’s imperative to manage the situation safely and prevent it from worsening. Here’s how:

Shut off any power around the area (electricity and gas)

Safety first. If you have any electrical appliances, outlets or devices in a flooded basement, do not enter it as they may cause electric shock which can be fatal. If you can’t access your electrical panel safely, call a licensed electrician to do so.

Locate the leak

Look for evidence of water behind furniture and appliances and along baseboards and beams. Darkened or stained surfaces and warped flooring are telltale signs of water damage. 

Call a pro

After calling in the electrician (if necessary), contact a professional plumber who can address the immediate problem, assess the overall impact of the basement flooding and identify the need for a follow up with a foundation contractor.

Call your insurance company

It’s easy to forget this crucial step when dealing with the stress of water in the basement, but it’s an important one. Take pictures and detailed notes and also get receipts for work done by professionals.

Pump out the water

If you have a sump pump, make sure it’s working – it could be the cause of the basement flooding and might need replacing. If there’s less than two feet of water, a good old bucket and some towels should do the trick. If there’s more than two feet, call a water-removal specialist. Either way, act fast – you don’t want mould to grow. 

Dehumidify the area

You want to get the basement as dry as possible. Fans may help but a dehumidifier is essential to draw excess moisture from the air, walls, and floors. Again, you don’t want to give mould a chance to grow.

Remove all porous materials

Anything wet or soggy has got to go. This is a good time to assess damage and note any items that may justify an insurance claim. 

Throw away contaminated items

As much as it hurts, sometimes items just can’t be saved. If, after 48 hours, items are still damp or wet, it’s best to bin them as they’re susceptible to bacterial growth.  

Repair any broken pipes or foundation 

If the basement flooding was caused by a broken pipe or foundational issue, now is the time to call in the professionals. Have them assess the scope of damage, make immediate repairs, and supply and install any necessary replacements to ensure the work is done properly. 

Why call in professional contractors?

You may have identified the source of basement flooding, but that’s just the beginning. It is always advisable to call professional contractors in for a thorough assessment and treatment of the basement flooding. A professional contractor can cite issues beyond the average homeowner’s grasp – like the integrity of the foundation’s footing, shifting of foundation walls, plumbing failures, and more. Plumbers can address any plumbing failures, such as a leaking pipe or appliance, while a waterproofing contractor or even a knowledgeable general contractor can fix foundational leaks and offer solutions, such as a sump pump or drainage, to ensure the basement stays dry. Licensed professionals ensure this important work is done properly.

Cost to fix a flooded basement

According to the Government of Canada, repairing a flooded basement has an average cost of over $40,000. This takes into account the extent of the water damage, the type of water in the basement flooding (whether it’s hazardous with detergent chemicals or contains sewage), its professional removal, and the removal of any mould and mildew growth.

Most cities have a Basement Flooding Protection Subsidy Program that offers homeowners a maximum-amount subsidy to install a sump pump and disconnect foundation drains from floor drains. There are some exclusions, but these programs cover most of the plumbing required for repairs and ensure the work is done by licensed professionals. Google it in your city to see the maximum eligible subsidy limit for your property and find out exactly what’s covered.

Tips to prevent basement flooding 

While professional contractors play a crucial role in keeping basements dry, there are many simple ways homeowners can help prevent basement flooding. 

Clean your gutters regularly

Rain gutters control the flow of rainwater along the rooflines to protect the roof, as well as the walls and foundation. They get filled with leaves and can clog over time, but cleaning them is pretty simple. You’ll need a ladder to access gutters, which should be cleared out every spring and fall. If you’re not keen on climbing a ladder, hire a professional; the average cost is $175-$295.

Clear debris from storm drains

Storm drains along curbs are usually cleaned by city crews throughout the year, but leaves and garbage can quickly gather and cover drains. If debris has accumulated, be sure to clear it away to allow  excess water to drain freely. 

Fix Cracks in foundation and windows

Do a home walkthrough to check for cracks in the foundation or windows. Immediately seal any cracks with a proper sealant, such as caulk.

Install or service your sump pump

Sump pumps pump water out of the house and away from the foundation to prevent basement flooding. They also help keep the area beneath the home dry. If you don’t have one – get one. If you do have one, get it serviced regularly as a simple blocked pump switch could lead to drainage failure and basement flooding. Sump pump locations vary depending on a home’s layout but are usually located in the utility room. It is a circular covered drain, generally flush with the floor, with a pipe leading out of it. Your contractor should be able to tell you where to find it if you can’t see it.

Test floor drain

Pour water down any basement floor drains to make sure that they are, indeed, properly draining. It’s a good way to suss out any blockages or sump pump issues. 

Set up a flood alarm

Flood alarms are so cool. These small, battery-operated sensors are installed near baseboards to monitor changes in moisture levels. They connect to smart home systems and alert you if there’s any water detected. Keep in mind, they won’t prevent basement flooding but they do catch it early so it’s manageable to remedy.

However you use the basement, the idea of it flooding can be super scary. No one ever wants water in a basement. Thankfully it isn’t hard to prevent basement flooding. Between DIY maintenance and the services of professional contractors, a dry basement is definitely doable and pretty nice to come home to. 

Smart Reno helps you find trusted contractors

With so much to think about when it comes to fixing and preventing a flooded basement, it’s important to find a professional you can trust. Get up to 3 free renovation quotes, learn more about basement renovations and talk to an expert about renovation financing.