You Can’t Paint Your Basement Dry!

I trully admire the tenacity of most DIYers. As a matter of fact, I am (or try to be) one. Yet, I am surprised to see how often some of them get into trouble for refusing to recognize that when it comes to home improvement, some things must be dealt with by a knowledgeable professional.

Basement walls happen to be one of these areas in which trying to cut corners instead of hiring a good company, will not only fail to deliver good and long-lasting results, but can also lead to serious consequences. 

One of the most popular DIY approaches to dealing with basements is to paint them. If they are leaky, we are often advised to use a waterproofing sealant. If they are just ugly and dirty, we are encouraged to spruce them up with a nice coat of latex paint.

After all, paint is inexpensive, anyone can use it and we like to believe that a nice coat of paint can make almost anything look great! Anything but a basement wall that is. Why is that?

Every Basement is a Wet Basement

If you are one of those fortunate homeowners who have a properly waterproofed basement – something that can only be achieved by a combination of proper foundation drainage, a good sump pump system with an unobstructed discharge line, proper grading, clean working gutters and extended downspouts – you are probably surprised by the above statement.

Sure enough, your basement looks dry. No water stains on the walls, no efflorescence, no puddles around the floor, and no visible leaks around the corners. But is it really dry enough for paint?

The Clay Bowl Effect

Once upon a time, when your home was first built, a big hole was dug right there where it now sits. Inside that hole, a concrete box was either built or poured to serve as the foundation of the new home. Then, the hole around that concrete box was backfilled and the box became your basement. That soil used to backfill the hole is loose, fluffy and will never be as compact as the undisturbed parts of the terrain. As a result, it absorbs water like a sponge and causes it to pool right next to your foundation walls.

If the foundation is not properly drained, hydrostatic pressure builds up and pushes against the wall causing water to seep into the basement, usually through corners and joints. What if your basement is properly drained and looks dry as a bone? Why can’t you spruce up your walls with a nice coat of paint?

Even if your basement has proper drainage, concrete is a very porous material, and the ground will always be wet, especially during the rainy season and snow melt. That means that there will always be some level of moisture seeping through the walls, and under typical conditions, evaporating into the basement. Cinderblock walls are even more problematic, because they are also hollow, so water tends to accumulate inside them.

Besides ground water seepage, basements also have moisture problems due to condensation, caused by the differences of temperature between the basement and the surrounding areas. And let’s not forget plumbing leaks and other water-related incidents.

What happens when you add paint to this equation?

For a short period of time your basement might indeed look great. The paint will seal the walls and keep water from seeping in, but this won’t last for long. Eventually the water will build up behind the coat of paint and one day, it will cause the paint to bubble, flake and peel off. So a few months down the road your basement floor will be covered with paint chips, which might be a problem if you have pets or small children; and it will look just as ugly as before. But wait: it gets worse. If you happen to have used latex-based paint – another unfortunate but popular DIY choice – you might have an even bigger problem to deal with: mold. Latex is an organic material, which feeds mold.  When you combine organic matter with basement humidity, you create the perfect conditions for mold to thrive by providing the three elements it needs to survive: warmth, moisture and food.

What if I use masonry waterproofing sealants?

Masonry waterproofing sealants are sold as a superior alternative to paint because they are not made with latex, and according to the manufacturers, they penetrate deeper into the concrete, rather than laying on the surface like regular paint; therefore they are less likely to peel off. Notice that I said “less likely.” Why is that?

If you read the manufacturer’s instructions for some of the most popular brands of DIY grade waterproofing sealants carefully, you will notice one important thing: they all recommend that before applying the coating, you make sure to locate and address the source of the seepage problem. In other words, your basement needs to be properly waterproofed with good drainage, gutters, grading, etc. before you apply the sealant. The manufacturers know that you can’t stop seepage without dealing with groundwater.

Waterproofing sealants should therfore only be applied to the interior of the basement walls once proper yard and foundation drainage are in place, and the bulk of the runoff and groundwater that would be accumulating in the backfill is being diverted elsewhere. The waterproof coating, which is clearly not to be used to stop serious leaks, would basically be used only to keep water from infiltrating the concrete and evaporating into the basement when the ground is wet. And that is a good thing, right?

The fact that you can do something doesn’t mean you should!

It is really your choice if you do want to seal your basement walls, but consider the following:

If you read the instructions a little further you will also notice that, when you follow all the recommendations concerning drainage and surface preparation, these coatings are only guaranteed to work in basements for 10 to 15 years.

So, in the best case scenario, after this time has passed, you would have to reapply the coating because just like regular paint, the sealant will no longer work. 

Furthermore, the U.S. Department of Energy recommends that basement walls be allowed to “breathe” so that the moisture in the concrete can evaporate into the basement.

To keep the evaporated moisture from raising the relative humidity levels in the basement, a vapor barrier can be used to intercept water and divert it to the drainage system. A basement dehumidifier will address any additional moisture, including moisture from condensation.

Better (and long lasting) Solutions for Basement Walls

Whether you just want to spruce up your basement walls on a budget, prepare them for finishing in the future or go for a complete basement finishing, there are basement wall solutions out there that will outperform and outlast paint and sealants. They are basically divided in three categories:

• Vapor Barriers:
  There are many types of vapor barriers that can be used to line basement walls. Straight, block walls, can be covered with white acrylic wall panels. They improve the look and when tucked into the interior drainage system, intercept and collect water seepage, preventing evaporation into the basement. Irregular walls can be lined with a white, 20 mil poly sheet of the same kind used in crawl space encapsulation. For extra energy savings, you can opt for installing a radiant vapor barrier, with a silver lining that helps conserve heat by reflecting it back into the basement.
  
  
•  Vapor Barriers with Insulation:
  If you want to make your basement more energy efficient but don’t plan to finish it in the future, consider encapsulated, insulated basement wall panels to add R-value to the basement walls and spruce them up on a tight budget.
  
  
• Basement Finishing Wall Systems: 
  If you are finishing the basement, insulated, cement-core basement finishing wall panels are the best choice for a number of reasons. The R-13 rigid foam board and the vinyl-lined cement board are 100% waterproof and mold resistant. Even if your basement floods in the future due to a plumbing accident, for example, the walls will not be damaged or grow mold. Installation is clean and quick, no framing required and the panels are much stronger than drywall. You can hang flat screen TVs and book shelves on them without the need to look for studs, or use any special hardware. The vinyl finish makes cleanup a breeze and can be easily removed and reinstalled, should you ever need to access the basement wall to inspect for cracks or work on plumbing and wires.