Why Waterproofing Is Crucial When Renovating A BasementWater and basements are never a good combination. When my family and I first moved into our home over 15 years ago, we were told that the basement could get some moisture during the spring and summer from rain. Fast forward to summer, where we were vacuuming up 3 feet of water out of our basement. Our home had become a swimming pool. We were lucky that not much had been destroyed, only some of our faith in humanity. In the end, we had to fight the previous home owners into paying for proper draining in the basement since the home had a pre-existing condition that the previous home owners knew of but never disclosed.

Water damage is never fun and it can ruin precious family items and cost bundles of money to repair. Even moisture, which you think wouldn’t pose as big of an issue, can become a problem over time. Water seepage through walls or flooring, condensation from warm and humid air, and water vapor diffusion coming in through the foundation are all things that should be checked before a renovation moves forward.

If you are beginning with an unfinished basement, there are several preparations you need to create a functional living space in your basement. You don’t want to go through the entire renovation process, only to come home and find an unexpected indoor pool, complete with all of your furniture and belongings bobbing along like pool noodles.

Waterproofing Options

Before you begin waterproofing, research all the numerous ways you can help keep water out of your basement, such as:

  • Subfloor and baseboard drain systems. These specific systems are integrated below the basement slab (subfloor) or along the baseboards. If used in combination with a sump pump, drainage systems can capture and direct water that enters the basement, but they will not keep water out.
  • Negative-side sealant. You can paint or apply this product directly onto the interior walls of your basement foundation to create a water-tight seal and reduce the possibility of water coming in.
  • Exterior grading and draining systems. You can collaborate with a landscaper to help taper your property away from your home. This ensures that any water or snow will drain away from the home, instead of towards it. French drains can also be added to the yard to help redirect the standing water and rain, while reducing the risk of basement flooding.
  • Repairing the foundation. Foundation cracks are fairly common, especially in older homes or homes that were constructed during the winter months. Cracks in the floor or walls of the foundation can allow water to seep into the space. Repairing these cracks and sealing them, will reduce the risk of water entering your home.

Another way to help water proof your basement is with the addition of a sump pump system. Sump pumps take up some space, but without one, rain water and spring runoff can come into your space. Sump pump systems work especially well with numerous others basement waterproofing methods and are crucial during actual floods by helping move water out of your basement and reducing damage to the area.


When looking into basement waterproofing costs, it’s key to keep a few things in mind. First off, it is necessary to identify the source of the moisture. There are both interior and exterior solutions for waterproofing your basement. Interior-based waterproofing methods are often looked at as the negative solution because they involve pre-existing water issues. Fixing a water problem from the inside may be cheaper, particularly in cases where exterior work isn’t practical or at all possible.

Drainage systems help move water out of the home through a hole or trench in the foundation paired with a sump pump. This system should also include insulation of basement walls with a vapor barrier to fight against condensation. A drainage system can start at around $2,000 and can increase based on how much work needs to be done to fix the issue and how big your space is.

Sealants aren’t highly rated by waterproofing companies because they can fail easily. Waterproofing sealant can range from $4 to $8 per square foot. It’s a cheap way to begin your waterproofing, but it’s not the ultimate solution. It’s more of a band-aid until you can get the proper channels underway to correctly waterproof your space.

Epoxy ejections, similar to sealants, are not highly favored because they too are a temporary solution. The epoxy can fill cracks in concrete walls, but again, it’s not a final solution to the problem. These injections can begin at $300 and will increase depending on how many injections you need.

Exterior waterproofing methods are preferred, simply because they aren’t quick fixes. They aim to prevent the water from even entering your home. It may cost more up-front but it could potentially save you a bunch of money in the long run.

Installing an underground trench or perimeter drain is the preferred method of contractors due to its effectiveness. The average range of an excavation is between $20k to $30k and can even go as high as $80k. This number would depend heavily on how much digging is required, how accessible the area is, and how much landscaping or other work needs to be done once the excavation is complete.

Something else that can cost you big bucks are cracks in your foundation. Depending on the state of your foundation, it can cost anywhere from $500 to $15k just to fix your foundation, which may not even completely eliminate the problem. However, fixing your foundation could end up saving your home, so it’s something to be mindful of.

Be sure to get some estimates from several different professionals and see which one is the best for the money. It’s a big investment, not only to renovate a basement, but to hire a contractor to perform all the work needed. According to Angie’s List reports, the average homeowner will spend roughly $7k on basement waterproofing. That’s a lot of money. Things add up quickly, which is why it’s really important to get several estimates. Keep in mind that most professionals you come across will be true to their word on pricing. However, there will be some that rely solely on sales tactics and not the quality of work performed. Those are the contractors to steer clear of, they will not complete the job the way it’s supposed to be done.

Every basement water problem is unique and requires a specific solution that is best tailored to the situation.

If you plan on adding water back into the basement in the form of a wet bar or bathroom, it’s important to remember that you will need a new waste line to get the bathroom water out of your basement or lines for water for a sink. Be sure to tell your contractor all plans you have for the basement so they can help prep your space for all possibilities.

Creating a space in a basement takes careful planning and steps of preparation. It’s a big area in your home and can be used for a number of things. It can be a hangout room for kids or a playroom. It can be an office, a gym, a guest room, a small apartment for older children who haven’t left the nest yet. Whatever the plan is, make sure you get it all done right.

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