How to Waterproof Your Basement in 5 Steps

Ring's End carries premium products to waterproof your basement. Depending on your level of expertise and the water issues you are experiencing on your property, it may be appropriate to hire a professional to do the work. This article is intended as a guide for the DIY'er.

Before you venture into waterproofing your basement, you should understand why it might be wet in the first place. Because most basements are below grade (ground), they are more prone to accumulating excess moisture and suffering water damage. Here are some of the more common reasons why you may end up with a wet basement:

  • Cracks in your house's foundation are a surefire way for water to seep in through your basement walls and floors.
  • Basement doors, windows, egress windows, and window wells that aren’t secure are other paths for water seepage.
  • Inadequate drainage is a major cause of a wet basement. When rainwater is not properly directed away from your home, it will sit at the house’s foundation and seep into the basement.
  • Improper drainage can be the result of a poor drainage system, improperly installed or clogged gutters, or even sloping around your home. If your land is sloped toward your home, water will run toward and accumulate around your house’s foundation.

Interior Waterproofing Your Basement Walls and Basement Floor

The foundation is said to be the strongest part of any home. But as a house’s foundation shifts and settles into the earth, cracks will inevitably develop and water can seep in, resulting in a wet basement. Typically, these foundation cracks can be fixed with easy DIY basement waterproofing solutions. There are certainly exterior waterproofing instances where a contractor may be required to repair major foundational damage or a landscape architect/civil engineer would recommend regrading your yard and/or redesigning your drainage system. However, here, we’ll focus on interior waterproofing that you, as a homeowner, can do yourself to achieve a dry basement.

Before You Begin

First, you'll want to clean up the areas you'll be waterproofing. Many of the waterproofing products listed below will only work if applied directly to the substrate, so if there are any existing coatings on the surface, wall, or floor, they must be removed. Old paint can be removed with a wire brush, sandblaster, or other methods. Please contact one of our Paint Centers for advice on how to best remove old paint safely, as you must always wear proper protective gear when removing paint. Wash the walls of dirt and dust using a scrub brush and warm water with a little bit of dish soap. If you see any mold, you can add bleach into the solution (1 cup of bleach per gallon of water). However, first check the ingredients in your dish soap and do not mix bleach with any products containing ammonia! Rinse the walls with warm water after washing them, and let everything dry thoroughly before moving on to the next step.

*If you see any white, powdery, crystal-like powder on your masonry walls, that is efflorescence and needs to be removed with DRYLOK Concrete and Masonry Liquid Etch & Cleaner or muriatic acid. Please refer to the manufacturer's directions before using.

Step 1: Clean the Area

First you'll want to clean up the areas you'll be waterproofing. Many of the waterproofing products listed below will only work if applied directly to the substrate, so if there are any existing coatings on the surface, wall or floor, they must be removed. Old paint can be removed with a wire brush, sandblaster, or other methods. Please contact one of our Paint Centers for advice on how to best remove old paint safely, as you must always wear proper protective gear when removing paint. Wash the walls of dirt and dust using a scrub brush and warm water with a little bit of dish soap. If you see any mold, you can add bleach into the solution (1 cup of bleach per every gallon of water). However, first check the ingredients in your dish soap and do not mix bleach with any products containing ammonia! Rinse the walls with warm water after washing them, and let everything dry thoroughly before moving onto the next step.

*If you see any white, powdery, crystal-like powder on your masonry walls, that is efflorescence and needs to be removed with DRYLOK Concrete and Masonry Liquid Etch & Cleaner or muriatic acid. Please refer to manufacturer's directions before using.

Step 2: Plug Holes

For any holes, use hydraulic cement, such as DRYLOK Fast Plug, to plug any obvious holes and large cracks. Hydraulic cement seals cracks and holes in masonry, and prevents water from flowing through them, even under pressure. DRYLOK Fast Plug will set and harden very quickly, in 3-5 minutes, so have a plan before you start! Use a trowel to smooth the cement before it sets. 

Step 3: Fill Cracks

Fill smaller cracks with a Masonry Crack Filler.

Step 4:  Seal Openings

Use caulk to seal doors, windows, and window wells. We recommend an elastic sealant such as Big Stretch Sealant or Lexel Sealant, both of which are waterproof and flexible.

Step 5: Apply Waterproof Coating

After your holes and cracks are sealed, use a waterproof coating on your basement surfaces. DRYLOK Clear Masonry Waterproofer is a great product that is guaranteed to protect walls and floors against hydrostatic pressure and water seepage. DRYLOK Masonry Waterproofer also comes in white and gray, but these two can only be used on walls and not on floors. Apply the concrete sealer with a quality nylon bristle brush or 3/4" nap roller and make sure to work it into the pores of the masonry. Proper coverage and a minimum of two coats is required to warranty waterproofing. Read all manufacturer guidelines and instructions before applying.

*PRO TIP: Tape along the concrete floor 1 inch out from the base of the wall, and paint DRYLOK on the walls, along the seam between the wall and the floor, and on the floor up until the tape. This will help prevent water from migrating down the exterior of the foundation and in through the seam.

Basement Waterproofing Tips

  • Don’t perform any crack repair or sealing until all standing water is first removed from your basement floor.
  • Consider running a dehumidifier in your basement to reduce condensation. This will help prevent mildew and mold growth.
  • If your dryer is in your basement, be sure that it's correctly hooked up to the vent and that you don't feel any air leaking around the hose. The hot, moist air from the dryer can cause condensation if it's not venting correctly.
  • Another source of condensation in your basement may be sweating pipes. Check that your pipes are properly insulated with this guide: How to Insulate Pipes and Prevent Pipes from Freezing.
  • You can paint over DRYLOCK Waterproofer, and we recommend a paint that will perform in high-humidity environments, such as Benjamin Moore Aura Bath & Spa.

Exterior Waterproofing

Exterior waterproofing your home can be a big undertaking, and we recommend hiring a contractor or landscape architect for a consultation if you believe there are serious cracks or deficiencies in your concrete foundation or if you have groundwater pooling around your house. However, there are easy do-it-yourself fixes that you can try before excavating your yard!

  • Don’t plant flower beds or bushes that require watering too close to your house.
  • Make sure your gutters are clear and flowing properly to keep water flowing away from your house. Check out our guide on gutter guards and how to properly protect your gutters: Best Gutter Guards to Protect Your Gutters.
  • If your walkway or patio are sloped toward your house, they can contribute to water pooling around your foundation. You may be able to re-level the slabs so that they drain away from the house instead of toward it.

Preparing for Basement Floods

One last thing you may want to consider adding to your basement waterproofing system is a sump pump. If your house is located on a high water table, some basement flooding may be inevitable during heavy rainstorms. A sump pump can either be above or below (submersed into) your basement floor, and pumps out and discharges water from inside to outside.

Does My Crawl Space Need to be Waterproofed Too?

If your house has a basement crawl space, it is also necessary to not only seal the interior and exterior walls, but also any crawl spaces that may allow for water seepage.

When Should I Call a Professional Basement Waterproofing Company?

If you're unsure of how deep the damage goes and whether or not you can properly fix the water problems yourself, calling a professional waterproofing expert in your area may give you peace of mind. 

Many waterproofing service companies offer a free inspection to tell you the extent of damage and the cost of repair services. If they find that your home has extensive basement leaks that have caused major structural damage or your basement is in need of foundation repair, it may be best to have a professional handle the work.