How to Waterproof Basement

A basement that’s constantly leaking is, well, let’s face it—annoying. Forget storing anything of value in this moist space.

The smell of mildew is anything but inviting and we all know that moisture leads to mold. So get to the source of your problem and take the proper steps to waterpoofing your basement. Most issues are relatively easy to identify and remedy, others may require a phone call to a professional.

A caveat before we get our feet wet (pun intended): If you have standing water in your basement, save yourself the time of reading this post and call a pro. You’ll thank us later.

Determine the source of the problem.

Before any action can be taken, you’ll need to identify the source of your moisture issues. Let’s start at the foundation.


The best time to figure out what’s going on with your foundation is during a heavy rain or immediately thereafter. If you see water pooling around your downspouts within 5 feet of your foundation, your wet basement is likely the repercussion of  moisture accumulating too close to the structure. The remedy is an easy one, though—purchase gutter extensions at any local hardware store to direct the rainwater further away from your home’s foundation. Most extension pipes will cost between $10 and $15 depending on your chosen length.


If rainwater is pooling in areas other than around your downspouts, your landscaping may not be graded properly. Your landscaping should be sloped away from your home to allow for water to flow freely away from the foundation. Dirt that’s been backfilled around your foundation will typically settle lower than the surrounding dirt. This causes the ground level to sink and slope toward your home. If you’re on sinking ground, create a proper, gradual grade by adding dirt up against your foundation so that the landscape slopes at least 2 inches for every foot you step away from your home. Make sure the soil is at least 6 inches below your siding or other building materials to avoid potential rotting. If you run into problems creating the proper grade, a professional landscaper can best consult you on this issue.

Humidity & Condensation

If pooling water isn’t your problem, let’s try another test. Have you heard of the foil trick? Adhere a small square piece of foil to your basement wall and check back after 24 hours. Has condensation built up on the side of the foil closest to you? If yes, you have a humidity issue in your room itself. Purchasing a dehumidifier will help moderate moisture levels and reduce the growth of mold. If condensation builds up on the side of the foil closest to the wall, the issue is likely due to moisture from the ground just outside your home. Waterproofing will serve you well in this scenario.

Waterproofing Solutions

Seal large cracks in your walls. Any gap wider than 1/8 inch needs to be sealed with a caulk designed for masonry before you begin to apply any waterproofing treatments.  A product such as Drylok is ideal for moderate or intermittent leaks, and a great solution for applying over a large area such as walls and floors. Drylok is a waterproofing paint that expands as it dries to become part of your wall. If you have a really problematic, isolated area of moisture in your basement, perhaps you want to consider a waterproof coating like Super Thoroseal or Xypex that act more like concrete and bond to the wall. These coatings are not as easily applied over large areas. Based on your issues, determine what’s best for you.

Consider treating your foundation with Hydroclay, a waterproofing version of Bentonite clay. This product is injected along the perimeter of your home and is known to absorb large amounts of water. The clay fills in voids in your foundation and permanently seals your basement. This is some seriously hard working stuff, the same product used to waterproof tunnels and manholes.

Installation of sump pumps and upgraded drainage systems are also options if you have serious water issues. You may need to consult a professional service so that you’re spending your money and time on the proper solutions.

Hopefully these tips will assist you while you are waterproofing your basement. However, if  you do not feel comfortable doing it alone, don’t hesitate to give us a call and we’ll help you out!