Basements are a worthy addition to any house, especially if you live in an area prone to severe weather. As a kid, I was always taught to go to the basement in the event of a tornado.
Aside from protection, they offer multiple benefits. Some people may choose to turn them into a root cellar for food preservation (a common technique before the invention of refrigeration), or take advantage of the extra space to add another level to their house by finishing the basement.
Having a well maintained basement can actually increase a home’s value.
But how do you maintain and improve this below-ground space? One very beneficial step is to waterproof the area.
Table of Contents
- Waterproof Sealers
- Waterproof Paints
- Things to Consider Before Getting Started
- The Components of a Basement
- Water Problems in a Basement
Sealers help to waterproof your basement by seeping into the pores of the concrete and “sealing” them. It can help seal existing cracks and prevent future spalling. Some products penetrate deeper than others, but the mechanism of waterproofing is similar.
You should seal your concrete before you paint it.
Top 3 - Waterproof Sealers
RadonSeal Concrete Sealer
Liquid Rubber Foundation & Basement Sealant
Gorilla Waterproof Patch & Seal Liquid
1. RadonSeal Concrete Sealer
This is a well-loved, easy to apply sealer that comes in a 5 gallon bucket. Depending on the thickness and number of coats applied, it can cover close to 500 sq. feet with one bucket.
You will notice that RadonSeal also helps to block the smell of radon gas. Radon gas is naturally emitted through the decay of organic materials in nearly all soil types. If there is quite a bit of it, it does carry some health risks.
Radon is odorless so you won’t be able to smell it, but this sealant will help to reduce the radon offgassing that may be happening in your basement as well as protect against moisture. Though it is on the pricey side, its ability to seal untreated concrete is unmatched.
Be advised, you will need a sprayer attachment to apply this sealer which does not come with just purchasing the bucket. When spraying, it lays down as a fine, colorless mist.
You can also apply it with a roller, but I wouldn’t recommend that as you will end up using more product and won’t be able to cover as much square footage. A little goes a long way with this one!
If you are wishing to paint as well as seal, this needs to be applied before your paint, and the paint you use should be a masonry paint (which tends to have less waterproofing abilities).
2. Liquid Rubber Foundation & Basement Sealant
Just as its name suggests, this will help you place a strong, rubberized seal that is highly beneficial for waterproofing. If you are looking to spot treat existing cracks or seal the joint between foundational walls and the floors, this is the perfect pick.
It goes on black with the consistency of tar and dries to a matte black finish. Once fully dried, it has the same moisture repellent properties as rubber.
It should be applied with a brush or a roller and laid on fairly thick. Using a medium nap roller on walls will coat it sufficiently & use a hand brush on touch ups or floor joints.
I would recommend applying this when it is fairly warm (above 60 F) as colder temperatures may make the consistency difficult to work with and can cause it to “film up” while you are still applying it.
While you can apply this to your entire floor, be advised that a 5 gallon bucket of liquid rubber will only cover about 100-125 sq ft, so you will need multiple buckets. If applying on a horizontal surface, make sure the floor is level & you spread it out immediately.
One drawback I found with liquid rubber is that it can be a mess to work with. Work quickly and diligently, using only what you need & cleaning up as you go. Also, it does take around 2 or 3 days to be fully dried, so plan accordingly!
3. Gorilla Waterproof Patch & Seal Liquid
This product is best used for touch ups & spot sealing only.
The makers of that infamously strong super glue also have a watertight sealant that is an excellent choice for waterproofing around windows, leaky pipes, and wall joints.
The Gorilla Waterproof Liquid has a medium viscosity thickness (similar to honey) that applies easily with a paint brush and once it is dry, has the look and feel of rubber. It doesn’t drip easily so it is effortless to place on the pipe joints in your basement ceiling if you notice them leaking.
After it is applied, it takes around 24 hours to cure and it will cure clear. Once it’s no longer tacky to the touch, you can paint over it. If you use multiple coats or apply it too heavy, it could take longer than that, so always do the touch test before you put anything over top of it.
Heads up when storing the leftovers - you absolutely must clean the inside of the lid and the edges of the can, or else you are going to have a hard time getting it open again if you need to do any touch ups. Trust me, I learned this the hard way.
After you have sealed the concrete (or it was sealed previously) you can now paint! Even if the sealant you used is, hopefully, highly waterproof, you still want to make sure the paint you use can offer the same benefits.
Note: Many of these paints state they should only be used on bare concrete with no other products applied, but professional consensus is that using them over top a sealant is completely fine.
Top 3 - Basement Waterproofing Paints
Rustoleum Watertite Latex
Rubberseal Liquid Protective Coating
4. Rustoleum Watertite Latex
A simple, no frills latex paint that offers waterproofing abilities. It applies very similar to wall paint, but a thin layer is all you need, especially if your concrete is already sealed.
Even though it’s only available in white, its waterproofing abilities (when used in combination with a sealant) help it to act like a sort of “primer” if you wish to add regular wall paint on top of it. Just make sure you use another type of latex paint as they usually provide the best waterproofing abilities.
It also claims to help with mold and mildew prevention, which can become quite an issue if water seepage is common in your basement.
For maximum waterproof properties, use two coats. It is advisable you use this only on walls that you plan to paint in the future. Avoid using it on floors as it may not hold up as well with heavy foot traffic.
Drylok is sort of a sealant and paint all in one. It can be used on bare concrete floors or overtop and existing sealer.
There is some debate within the contracting community about which is better for waterproofing: Watertite vs. Drylok. But they both offer their benefits.
Watertite is latex based and can be used on a wider variety of surfaces. Drylok comes in both acrylic and oil-based formulations. Drylok is also known to withstand higher pressure, making it slightly more beneficial for waterproofing exterior facing walls.
Drylok (especially the oil based variety) is particularly noxious, so you’ll want to work quickly and make sure to ventilate the area as best as possible. Ultimately though, the waterproofing will be better - especially when used in combination with a sealant.
Drylok also comes in several tinted color options.
6. Rubberseal Liquid Protective Coating
Similar to the liquid rubber sealant, Rubberseal functions in much the same way with the exception that it is thinner and comes in a wider variety of color options (currently there are 4 different colors available).
Also, it can be used to “paint” an entire floor as well as seal wall and floor joints.
Because it is thinner than a sealant, it dries quickly and you can apply multiple coats within one day. There is also minimal drip.
Application with a medium nap roller will give you the best results, as this formula is too thick to be sprayed without the use of specialized equipment.
Like most masonry paints, you have the ability to paint over top of it with waterproof latex paints after it has dried completely. This particular coating dries to a semi-gloss, rubbery finish.
Things to Consider Before Getting Started
Like almost all paint projects, it’s important to prep your concrete before applying any time of product on top in order to get the most bang for your buck.
At the very least, mop your concrete floors and walls with plain hot water to get up as much dust and grime as you can. If possible, it is highly recommended that you power wash the area to remove mold, mildew, lime, and salt buildups.
Also, don’t underestimate the power of doubling up your products. While most waterproof paints will give you a few years of protection, using them in combination with a strong concrete sealing will offer extra insurance.
The Components of a Basement
Basements are designed differently than other rooms in your house.
For one, the exterior basement walls are going to be sturdy, thick concrete (or some other form of masonry). This is because of the need to be able to withstand the weight from the house above as well as the pressure applied from the surrounding soil.
Second, basement floors are made of concrete for the same reasons. Even if a previous homeowner laid carpet or tile on top, the subfloor is almost always concrete.
Most plumbing and electrical accessories will be run across the ceiling of the basement. In an unfinished basement, this is easy to notice between the ceiling buttresses.
Water Problems in a Basement
If you decide to paint any part of your basement, you absolutely cannot skimp on waterproof properties. Basements are magnets for moisture by their design.
Water will always take the path of least resistance and gravity ensures it ends up in the lowest possible point. Any busted wall pipe or leaky appliance can cause water to make its way down to the lowest level of your house: the basement.
Soil is very absorbent and is constantly making contact with the exterior walls of your basement. If not properly sealed, any moisture in the surrounding soil can start to leak in through the masonry.
Though there’s not much you can do to stop a rainstorm, you should take extra precaution if you live in an especially wet climate.
Broken Rain Guards
Most (not all) basements have to incorporate something called an Egress Window for safety reasons. It allows anything that is designated as a room or dwelling to have an option for escape in the case of a fire or other disaster.
These Egress windows are usually within a dugout of soil that is reinforced with metal tubing in a semi-circle shape. Since these are below ground, the top of the metal tubing will have a plastic covering over it at the ground level called a rain guard.
The rain guard is just as it sounds: it prevents rain from entering the soil dugout and the egress window. Rain guards are, by design, easily removed from below for safety reasons.
Because of this, they are prone to leaks and damage. A damaged or leaking rain guard will greatly increase the risk of water damage in a basement.
A basement or a garage are the two most common places for a water heater. Water heaters can malfunction like any other appliance and cause issues in the basement.
Faulty connections, bad gaskets, or corrosion are most often the issues associated with water heaters and can lead to water damage in the surrounding concrete.
Water Pipes Bursting
A pipe bursting in any part of your house can be a headache. But since the water pipes in a home are usually run across the ceiling of a basement, having one burst at the basement level means it will pour all over your basement floor.
Even if it isn’t a noticeable “burst”, a leaking pipe can cause the same issues, especially if your basement isn’t visited and inspected very often. You may not notice a problem until it’s too late.
Some basements are outfitted with hookups for other large appliances like fridges, washers, and dryers.
If they are not hooked up properly or malfunction in some other way, any appliance that has a water line running to it is prone to leaking water.
Wear & Tear Over Time
Concrete is a naturally porous material and absorbs water fairly well. This isn’t necessarily a problem, but over time it can erode the overall structural integrity.
Having too many leaks or being in an especially wet climate that is prone to flooding will accelerate the concrete breaking down, so it is suggested you try as many waterproofing techniques as possible in your basement to extend the life of the concrete.
Spalling is a term that refers to a particular kind of damage that happens to concrete that experiences multiple cycles of freezing and thawing. It essentially means tiny pebble-like pieces of concrete will break off as it expands and contracts from the freezing water it absorbs.
This is really only an issue in colder climates and can be observed on the sidewalks and driveways of areas that are prone to a yearly freeze. It can happen in your basement as well.