Waterproofing Your Basement: The Basics

You bought your house because of the beautiful yard, the unbelievable hearth in the den, the two generous bathrooms and, of course, the enormous basement. You had big plans for that basement — it was going to be a home theater with a pool room, all very posh, but the first melt of winter had other ideas. Was that a little bit of water you saw on the floor? Maybe it was just a shadow. Or maybe it was water… are your dreams destined to be dashed to the ground?

Not necessarily. There are many ways to cure water in a basement, we’ll walk through some of the most universally effective options.

How Does Water Get Into a Basement?

So, there’s a prevalent myth among homeowners that wet basements are wet because they’ve been built near or below the water table. This literally makes no sense because that would have meant that the basement would have originally been poured underwater or into a muck-filled hole. That’s just not how basements are built. They’re formed and poured onto a dry surface that allows the material to dry and harden quickly. It’s not rocket science, but it is chemistry.

There are actually three common ways that water tends to enter a basement, any or all of which merit investigation. Those causes are:

Each of these causes is curable, depending on how much work you’re willing to put into the effort. There isn’t room in this blog to give an exhaustive tutorial, but we’ll give you enough info to get started so you’ll know enough to gather the materials and assistance you need.

Curing Wet Basement Syndrome

Because most basement wetness comes from one of the three sources listed above, it’s going to take some detective work to find it. This can be an absolutely aggravating process, especially if it’s only wet during certain times of the year or after particular types of weather. The good news is that a lot of the fixes that work for basement wetness are useful maintenance for your house as a whole anyway. If you go ahead and do these things and they don’t cure your basement, they were probably good for some other problem you didn’t realize you had.

Let’s talk wet basement cures!

Water Source: Poor Drainage

At the end of the day, a lot of your basement woes will be cured if you check the drainage situation around your house. First, the grade. Does the ground around your house create a sort of bank that diverts water back toward your foundation? Is it just totally flat? Ideally, you want a grade that slopes away from the foundation at a rate of six inches of drop for every 10 feet of run. That’s about a five percent slope. If you don’t have a five percent slope, you can create one with fill dirt, a rake and several weekends’ worth of labor, or a tractor if you have one available.

The second part of regrading is correcting the problems that caused the ponding effect around the foundation to begin with. Maybe you don’t have gutters and you really need them. Perhaps you have gutters, but they’re not really doing their jobs because they’ve not been maintained and they’re full of leaves and other debris. Clean them out and extend the downspouts as far away from your house as possible. You can purchase flexible plastic diverter extensions that make it easier to move water from your roof to exactly where you want it for a song at any hardware store.

Some professional contractors may suggest a French drain when this situation occurs. The truth is that often, French drains are overkill or simply can’t be expected to function properly due to the soil type in your area. They can clog easily, again, depending on the soil type, and then you have a very costly pipe full of mud buried next to your basement. Do all you can to improve the drainage around your home first, long before you consider the headache, expense and gamble that is a French drain.

Water Source: Leaky Windows

This sort of goes with the poor drainage, but if your windows are down in a well, it doesn’t really matter how good your drainage is, they probably need additional attention. If you can pinpoint the leaky window, great! But it’s pretty likely that if one is leaking, they’re all at risk. Check all the windows to assess their general condition. Basement windows are so often neglected, it’s not even funny. If they’re all in generally good shape, grab some caulk designed for either bathroom use or basement use and a putty knife and get to work.

Go ahead and remove the old caulk completely. Clean the windows well so the new caulk will stick. Apply that caulk as liberally as you can without making a huge mess. Go all the way around the window, don’t skimp. Once you’ve done that, go outside and repeat the process. For windows inside wells, head out to the hardware store and grab some basement window well covers that fit your well. They should slightly overhang the well, so that water is diverted away from the well.

Water Source: Leaky Appliances or Plumbing

If you corrected your drainage and you fixed your basement windows and there’s still suspicious water on your basement floor, it’s probably coming from inside the house. This is a game of cat and mouse that can drive you absolutely up the wall. Some common causes of mystery leaks can include:

Once you locate the culprit, you can finally correct the problem, or call in a pro to do it for you, depending on the nature of the issue. For example, if your leak is actually a drain line that’s improperly installed and is backing up during showers, this might necessitate a plumber. If it’s just a backed up condensation line, you can probably handle cleaning that out yourself.

After the Puddles Dry Out

Once you finally find the source of your basement’s leak and fix it, you can feel free to dream big again. But, remember that your basement is still a basement and you should always go with materials that can withstand water, just in case you spring another leak down the road. Tile and stained cement are both popular flooring choices and completely waterproof. You may need to get a little more creative if you have interior walls that you want to cover, but even tiling a few inches up the base of the wall can help protect any bathroom-safe wallboard from potential moisture issues.

Then again, maybe creating your dream basement is a project you’re not really ready to DIY just yet. In that case, go ahead and log in to HomeKeepr and ask your Realtor to recommend a general contractor. Your new contractor will be able to get you started in the right direction, including helping you select the best materials for your basement entertainment zone. While your GC is working in your basement, why not check out our maintenance list for late winter and early spring? It’s free and after you read it, you’ll know exactly what needs to be addressed around the house before the weather starts to warm up.