Category Archives: basement walls

Waterproof Paint, Plastic Vapor Barrier, Or Concrete Sealer?

What To Use To Control Moisture & Humidity In Your Basement

Generally speaking, homeowners now recognize the importance of creating a vapor barrier on their walls. Whether through waterproof paint, a plastic vapor barrier, a penetrating concrete sealer, or some other method, creating this barrier will prevent water vapor from seeping through the pores of concrete.

In a finished basement, a vapor barrier will protect drywall and insulation from the moisture buildup that would otherwise lead to mold, mildew, and humidity passing through the concrete walls and floors located within the space. In an unfinished basement or cellar, sealing the walls and floor will create a drier environment, protecting stored items from rot and mold, and helping to control that musty smell that’s notoriously present in below-grade spaces.

However, there are a lot of basements out there – and a lot of companies competing to earn your consumer dollar on products that will help to control that moisture intrusion. And, like all things in the home improvement industry, some work better than others.

Let’s take a look at the three most common methods of moisture control:

1. Waterproof Paint

Most popular among do-it-yourselfers, many homeowners will opt for waterproof coatings and paints that are available at most local box stores. These products sport big promises, low cost, and seductive warranties that make them look like they’re a foolproof choice for any basement.

Unfortunately, these products have three major weaknesses:

  • A Non-Penetrating Formula: These paints and coatings are surface-level only, and have a comparatively weak bond on your concrete surfaces. If this coating is used on surfaces that are dirty, the will peel off. They are also a weak choice for high-traffic areas of floor, where the surface coating can peel off.
  • Poor Resistance To High Alkalinity Levels: There’s a lot of chemistry going on in the concrete walls of a basement – and the moisture that passes through may be highly alkaline. This is particularly true if your basement walls are new, and haven’t completed the years-long curing process. This alkalinity can break the bonds of surface coatings, causing them to blister and peel off.
  • Vulnerability To Efflorescence Buildup: Along with moisture, minerals also pass through your basement walls. As the moisture evaporates or recedes, it can leave these minerals in the form of a white, powdery mineral salt known as efflorescence. As this builds up, it can also compromise the bond of paints and coatings. Read your warranty carefully, and you’ll see that it probably doesn’t cover walls with efflorescence!

To make matters worse, once these coatings fail, they can be extremely troublesome to remove. You’ll be working quite hard on those ugly, blistering, peeling walls – and most likely, you’ll be renting some equipment as well!

2. Plastic Vapor Barriers

Whether rigid or pliable, plastic vapor barriers are a good choice for preventing moisture that comes through basement walls. Because they attach mechanically to the walls, there is no concern of peeling or detaching from the walls as there is with waterproof paint. Additionally, this is the only solution that can also intercept water flooding through cracks in the concrete – ones that would otherwise bypass sealers and paint coatings. This flooding water would be directed to a perimeter drain system, presuming you have one in place. Typically, the seal is made permanent with epoxy or caulk along the top and seams.

Plastic vapor barriers install fairly quickly, and there’s no VOC’s or drying time to worry about. They can give a basement a brighter, more cheerful appearance, or they can be used behind finished walls.

There are three disadvantages to plastic vapor barriers

  • Cost: The cost to buy, cut, and attach plastic vapor barriers can be much higher than simply applying a concrete sealer or waterproof paint.
  • Mold Concerns: What happens to the moisture that collects behind this plastic vapor barrier? Many homeowners voice concerns of mold and mildew growth, although there is little scientific evidence to support a health issue of mold behind a sealed vapor barrier.
  • Not Ideal For Floors: While this is a great option for the walls, it’s a less-than-impressive option for the floors. On a very flat floor, plastic floor tiles (without chipboard present) can be a possible vapor barrier substitute, but these tend to click and make noise on less even surfaces.

Despite the disadvantages, these vapor barriers provide a permanent solution, where applicable, and could be considered for moisture control in many homes.

3. Concrete Sealers

For the purpose of this article, we’ll discuss sliane-based concrete sealers. These sealers penetrate deep into the pores of the concrete, activating with the minerals in the concrete to create a glasslike barrier deep within the concrete. They’re safe to use indoors, and contain little or no VOC’s (brand depending).

Sliane-based concrete sealers activate quickly, and can be applied to both cured and newly-placed concrete. They will not change the appearance of the concrete, efflorescence and acidity will not harm them, and they’re able to be painted over with ease. Installation is fast (done with a brush, roller, or sprayer), and they’re middle-of-the-road in overall cost.

Three disadvantages to consider are as follows:

  • Provides Moisture Control ONLY: Unlike plastic vapor barriers, this will not be able to breach cracks or stop flooding water. It’s meant only as a sealer for water vapor that would otherwise pass through the pores of the concrete.
  • Take Care When Installing: Sliane-based sealers cause etching on glass, should they come in contact with it. When installing, be sure to protect and/or avoid glass surfaces.
  • Possible to Overapply: Waterproof paints can be coated thickly, thinly, or in multiple layers, and it’s impossible to overapply a plastic barrier. But an installer should be careful to only use enough sliane-based sealer to damp the concrete, as too much will leave a white residue behind.

Sliane-based sealers are the ideal choice for basements that are damp but do not flood, as they are inexpensive, install quickly and subtly, and provide a lasting solution.

What’s Your Dehumidifier Up Against?

When Dehumidifiers Fail To Dry Basements…

Many of the most frequently asked questions we get at PPK, Inc. are united around a common theme:  the homeowner has installed a dehumidifier in their basement, and the space is still supporting mold growth.  The space doesn’t feel any less humid, and the system is running nonstop.

Typically, the homeowner’s next step is either of the following:

  • They buy and run an extra dehumidifier (or two)
  • They give up, call it a bust, and live with a moldy basement.

Let’s take a look at what some of these dehumidifiers are up against…

The Victim

A small basement dehumidifier draining into a utility sinkRight off the bat, I can see three serious issues here:

  1. The dehumidifier has no discharge tube draining the water away
  2. The washing machine is discharging into this sink (black pipe on right)
  3. The discharge tube is dripping on the metal surface that the dehumidifier is lying on.  I know this because the wood propping the dehumidifier up is showing signs of water damage and rot.

All of these things are compromising the dehumidifier and contributing to high humidity levels directly around the system.  The homeowner also told us that using this sink as a discharge outlet for the washing machine had partially clogged the sink.  It takes several hours for the sink to drain a load completely after it’s done with a cycle.

Home Dehumidifier Or Basement Dehumidifier?

One thing the homeowner did right was to purchase a dehumidifier that was designed for lower temperatures.  Far too often, a homeowner will opt for a dehumidifier system that’s been rated for the warmer temperatures upstairs — usually about 75°F.  However, it’s not uncommon for a basement’s temperature to drop as low as 55°F-60°F.

Why does this matter?  A dehumidifier operates by passing air over a cold coil stored within the system.  As the air cools, moisture is dropped on the cold coil in the form of condensation, and is then drained away. It takes a lot more power to cool air at a lower temperature.

If you put a home dehumidifier in a basement, it will operate at a small fraction of its rated capacity.  And worse, the cold coil can freeze in the cooler temperatures, causing the system to either turn off or malfunction.  Running a dehumidifier specifically designed for a cooler, below-grade space is ideal.

Open Sump Pit Blues

Next on the list of culprits, there was this:

A sump pump with a few boards placed over the lid, accomplishing nothing.Located about a foot away from the dehumidifier, this open-lid sump system is a disaster in the making.  The sludge-filled stone around the edges of the liner has been releasing a musty stink into the basement, while the liner is nearly always filled with pools of water.  Some of the wood planks are laying over the top of the liner in an attempt to do I-don’t-know-what, and one is actually sitting INSIDE of the sump pump liner.

What kind of chance does the dehumidifier have when this thing is right next to it?

Flooding Basement Hatchway Doors

If it had any chance at all, that chance is certainly destroyed by this:

Basement stairs flooding with waterAh, yes.  The clear product of years upon years of significant flooding. Poor grading outdoors has caused water to puddle around the outside of these hatchway doors, while the gutters above drench water down upon it.  It doesn’t help that the baseboard drain in front of it is completely nonfunctional, either!  (Fun fact:  A 1″ rainfall drops about 500 gallons of water on the average roof.)

With every heavy rain, the basement floods through the drain, the floor, the walls, the stairs, the windows… everywhere.  In fact, during the recent hurricane (Irene), it sounded like faucets were turned on throughout the space!

Case in point:

A basement flooded from the hatchway doors.Remember:  A dehumidifier is not a sump pump!

Are You Running Your Dehumidifier Nonstop?

That’s… not such a good idea.

Here’s the consequences of running an overwhelmed dehumidifier in the basement:

  1. The basement is still moldy and humid
  2. The dehumidifier is running nonstop

And, last but not least, this:

A utilitiy bills showing a drastic spike in the most recent monthThe difference between June, July and August?  The dehumidifier was running.  On the bill itself, this proved to be about a $60 spike in the bill, or about 6 kWh/day.  That was decidedly NOT what the homeonwer was expecting or hoping for!

So You Want A Dry Basement…

Perfect!  Who doesn’t?  You can achieve this goal in three simple steps:

  • Your first step to a dry basement should be to eliminate all sources of groundwater flooding with a system that works.  Get a reliable battery backup system to run during power outages, such as the one that the entire state of Connecticut for about a week after Hurricane Irene struck.  For this, you should hire a specialist (a basement waterproofer, not a plumber), ideally, one that offers a warranted solution.
  • Next, seal off any ventilation your basement is using.  Basement ventilation is an outdated building practice that is quickly being phased out of code.  It’s been proven that bringing outdoor air into the humid environment in a basement is counterproductive — and is also a major drain on your utility bills!
  • Humidity enters a basement constantly through the walls and floors.  Invest a little money and get a high-quality, penetrating concrete sealer to seal out the moisture.  This will reduce the load on your dehumidifier, prolonging its life and saving you money.  We defintiely do not recommend using a waterproof paint product on your walls and floors, or any other “coating” product.   Coatings work some of the time, but they can also do more damage than good.
  • Invest in a powerful, energy efficient dehumidifier.  They’ll cost several times more than the cheap models, but, then again, they’ll get the job done (Isn’t that what you want it to do?).  Your system should be self-draining — that way, you don’t have the daily chore of emptying the collection tray, and the system doesn’t shut off every 8-12 hours as it fills.  Find one that can remove at least 80 pints per day, and one with a blower that will circulate dry air everywhere.

Please bear in mind that Concrete Treat seals the concrete only — it will not be able to close cracks (We’re working on a product for that!), nor will it be able to waterproof the basement.  Only by waterproofing, sealing, and THEN dehumidifying can you count on a dry, healthy basement.

Can Fiberglass Insulation Grow Mold?

The Science Behind Fiberglass Insulation & Mold

Fiberglass batt insulation installed in the joists over a basement

Fiberglass batt insulation (glass wool) installed inside the floor joists in a basement.

There’s been a great debate in recent years over how effective fiberglass insulation is when installed in a moist environment.

Old school contractors swear by it, claiming that it is moldproof and appropriate for installation in basement and crawl space environments.

Newer building science thinking pins fiberglass insulation as a terrible idea for below-grade spaces, citing its being ruined by damage by mold, rot, and humidity.

Then old-school contractors retort that it’s the lack of ventilation, not the fiberglass itself that is the culprit.  And the debate rages on and on.

So What’s The Scoop?  Can Fiberglass Support Mold?

Let’s take a practical look at this. Fiberglass is made with:

  • Glass (Usually 20%-30% recycled industrial waste and post-consumer product)
  • Dyes (Fiberglass is not naturally pink!)
  • Paper Backing (Optional, but very common)
  • Resins (Optional — binds the fiberglass to the paper backing)

Of these, I think we can agree that at least two (the paper backing and resins) can support mold growth.

The proof, friends, is in the pudding.  See below:

Mold growing on the paper backing of fiberglass insulation

OK, so fair enough.  But what about fiberglass without paper backing?  That should work, right?  Except that fiberglass is porous and absorbent.

Consider these two points:

  1. Fiberglass can capture dust and dirt, holding it in its fibers, where mold can grow.
  2. Fiberglass can soak up moisture like a sponge and hold it against structural wood.

Exhibit A:  Fiberglass Filled With Dust, Dirt, & Debris

Dust filling fiberglass insulation from a leaky air ventIn this case, a leaking air duct from an old HVAC system has been blowing air into this fiberglass insulation for quite some time.  And unless the HVAC system has been properly maintained (it hasn’t), then you can be sure there’s plenty of mold spores in that dust as well.   The fiberglass has essentially served as an air filter — one that needs to be replaced.

Exhibit B:  Wet Fiberglass Leading To Wood Damage

Structural wood that's been damaged by damp fiberglass pressed against itIn this case, a slow plumbing leak several feet away had soaked the fiberglass insulation for several feet around it with light moisture.  In some areas, the fiberglass insulation had sunk and fallen off the ceiling, while it remained moist but in place in other spots.

In the places where it held in place, it sponged up the moisture and held it in place against the structural wood for months.  Eventually, the slow leak was discovered (a difficult challenge in an already wet basement that is rarely used) and was  removed.

This is what we found behind it:

Damp flooring that was made worse by fiberglass insulation.The floor above is springy and weak, sagging down underfoot.

Now, of course, the plumbing leak was the real issue in this case.  But the fiberglass, which held the moisture in and hid the problem for the homeowner, certainly didn’t help.

What Kind Of Insulation Should I Use Instead?

An image of a large open gap around an air duct in a basement

Air gaps are built into your home as it's built. Contractors create these gaps as they install air ducts, wires, and pipes in your home.

Instead of installing fiberglass insulation on your floor joists, we suggest that you consider rigid foam insulation on the basement walls.

While it’s a bit more expensive than installing fiberglass, the savings are definitely there. In fact, the US Department of Energy reports that as much as $400/year can be saved simply by insulating your basement walls!

The problem with fiberglass insulation installed in the floor joists is this:  Insulation is only effective when it can be installed in an unbroken sheet.

However, when fiberglass is installed in the joists, there are boundless opportunities for air to circumvent the insulation.

Pathways for insulation include around gaps in the basement door, up through laundry chutes, and through open gaps around air vents, pipes, wires, and more.

Transforming the basement into insulated space will also provide the benefit of protecting utilities stored in the space (HVAC systems, water heaters, furnaces, hot water pipes, and hot air ducts) from the colder environment.  And if your basement DOES flood, foam insulation will not soak up moisture, grow rot, or be ruined and need replacement.

Since you’re protecting the materials in the basement from water anyways, you should consider sealing the floors will also help to protect carpets from mold by holding back water vapor that would otherwise pass through the concrete slab.

The Moral Of This Story

If you’re installing fiberglass batt insulation in a finished basement, it can support mold growth.  It holds dirt, dust, and debris inside the fibers, and it soaks up moisture like a sponge.  Wet insulation sags, opening holes in the insular sheet.  And, really, fiberglass insulation has little or no insular value when it’s soaked with moisture anyways!

Moisture can enter a basement through the walls in many ways, including:

  • Water leakage through existing and newly-created cracks in the wall
  • Water leakage around pipe penetrations in the walls
  • Water vapor passing directly through the pores of the concrete
  • Moisture soaked upward during a flood in the basement

Before finishing your basement, be sure to address all sources of leakage and waterproof the basement.  You should seal the concrete and install a plastic vapor barrier on the walls to prevent water vapor from building up behind the walls and creating a moisture issue.  We do not recommend coating the walls with waterproof paints or installing fiberglass batt insulation.  Instead, install rigid foam insulation on all foundation wall surfaces in the basement.

To seal concrete in a basement, we recommend Concrete Treat:  Concrete Sealer & Blanket.  Our sealant is ideal for do-it-yourselfers — it applies safely and easily, and it dries in just 2-4 hours.  There’s no odor, and your concrete will not change in appearance.  You can even paint over it if you’d like!

You can buy our concrete sealer directly online, or you can give us a call at (203) 376-9180!

Sealing Your Concrete With Concrete Treat

Protect New or Previously Cured Concrete With Our Innovative Concrete Sealing & Spalling Protection Product

Concrete Treat is effective in both new concrete construction applications and in moisture-sealing in cured concrete. Once applied to concrete, it will harden in 2-4 hours, creating a glasslike vapor barrier seal. Once applied, the concrete is protected from moisture from rain, snow, and other forces– moisture that can seep below the concrete, freeze, and “pop” off the concrete’s finished surface.

In new construction, it’s proven to prevent concrete damage, such as spalling, scaling, flaking, or chipping that occurs during freezing temperatures. One 5-gallon container of Concrete Treat is able to treat up to 1,500 square feet. Click to learn more about third-party Concrete Treat product testing that has been conducted!

To order Concrete Treat today, or to contact us with questions, call or e-mail us today!

Application Guidelines for Concrete Treat

Installing the concrete blanket alternative on wet concrete in new construction

Concrete Treat is applied in a single application with an air or airless sprayer. Application is safe, fast, and easy, and Concrete Treat is neither toxic nor caustic.

The concrete sealer product is safe to apply to both wet and dry concrete, but care should be taken that it’s not applied to glass (cover all surfaces where treatment is not intended before spraying). Unlike tars, Concrete Treat will not have grade-line problems.

Unlike waterproof paints and coatings, it is not prone to peeling, flaking, and chipping off the concrete walls within a few months or a couple years.

Concrete Treat can be used effectively on masonry block, pre-cast and poured concrete walls as well as sidewalks, patios, garages, or any other concrete surface.

Concrete Treat arrives ready-to-use in a 5-gallon container. Application is convenient and easy for even the novice homeowner, and no special equipment, other than the sprayer, will be necessary. Concrete Treat can be applied to both the walls and the floors, giving total concrete protection to a basement or crawl space. It’s recommended that Concrete Treat be applied with an applicator whose orifice size is 0.035 inches ensure proper application. Apply until concrete is saturated, without stopping until the area is completely treated. After application, the equipment cleans up easily with soap and water– the seal should dry within 2-4 hours.

Once Concrete Treat has Sealed your Concrete…Spray on concrete sealer product in its bottle ready to use on concreter or in a basement

New Construction: Your sealed concrete is well-protected from the elements. Concrete Treat will act as a barrier, preventing moisture and salt from invading your porous concrete and damaging the concrete’s surface. Concrete Treat is long-lasting, and it does not yellow or become discolored by ultraviolet rays. It’s been fully tested by SGS US Testing and is proven to stop water without cracking– even in a 20-day freeze/thaw schedule.

For Homeowners: Your concrete’s surface will be ready for painting and coatings, while the sealant keeps humidity from passing through and helps prevent mold growth.

Concrete Treat can help to prepare a basement for finishing by sealing away humidity that would otherwise be trapped behind the basement walls and underneath carpeting, where it would promote rot, mold, and decay. Contact us today by phone or e-mail with your questions and orders!

Waterproof Concrete Paint: A Case Study

At Concrete Treat, we recently visited a homeowner with a big problem in his concrete basement. He had tried to use waterproof paints purchased at a local hardware store to seal his basement walls and floors. And then he tried to do it again. And then he did it again.

The final result? Multiple layers of disgusting, flaking mess all over his basement– a mess that did next to nothing to protect his basement from moisture penetration.

Flaking, Chipping Waterproof Paint On The Walls

Multiple layers of concrete paint on a basement wall that are blistering and peeling away.

When a layer of waterproof paint fails, it should be removed before a new layer is applied. Otherwise, the residue from the previous coating will prevent the paint from bonding properly — and the paint bonded to the old paint will just flake away when the original layer does.

The picture on the right-hand side shows a perfect example of just how ugly basement walls treated with waterproof paint can get.

In the photo, you can see three unique layers of waterproof paint that were used– one black, one dark blue, and one light blue. And despite these three layers, you can also easily see the concrete showing through in many areas.

The problem is this: while waterproof paint will seal a basement wall over the short-term, it can’t be relied on to hold its bond with the concrete over the years to come afterwards.

As moisture passes through the porous concrete walls, it will push continuously outwards on the waterproof paint, causing the paint to lost its bond with the concrete.

Additionally, long-term moisture will also leave a mineral deposit behind the concrete, known as efflorescence, which will also weaken the bond between the concrete and the waterproof paint.

In the end, using waterproof paints will only make the problem worse. This flaky, ugly mess will not hold back a significant amount of humidity, and it looks terrible on your basement walls.

Waterproof Paint On Concrete Floors

waterproof paint on a concrete basement floor that is failing

Waterproof concrete paint will quickly wear and flake off of basement floors, leaving an ugly floor behind that’s tough to clean.

In addition to the walls, the homeowner also applied waterproof paint to the floors.

Equally ugly, this coating also resulted in a failed coating. Normal wear and tear soon left the floor looking terrible, as the waterproof coating flaked off and left a big mess. In some areas, the waterproof paint was worn almost completely off.

Additionally, because this basement flooded often, multiple cracks formed along the concrete floor, as water began to seep upwards through the cracks.

The waterproof paint was unable to stop this water from flowing into the basement, and everything in the basement was badly damaged by water.

Waterproof paints and concrete sealers alone are not able to keep a basement from flooding. At Concrete Treat, we recommend that you use an interior perimeter sump pump system (with a battery backup pump) to waterproof any flooding basement before attempting to seal way water vapor. Once this is done, it is appropriate to seal the concrete with a sliane-based sealer only — not latex-based waterproof paints.

Alternatives To Waterproof Paint For Concrete Sealing

chipping, flaking waterproof paint and rusty pipes

Waterproof paint coatings generally last between 6 months and 3 years before signs of wear and tear begin to show.   Once it begins, it will get progressively worse.

Once waterproof paint outlives its welcome, it can be extremely difficult and labor-intensive to remove.

While it does little to hold back humidity, a portion of the paint will be trapped within the pores of the concrete, making it nearly impossible to properly remove.

This can ruin concrete walls for appropriate sealants in the future, and it can be a big challenge for homeowners wishing to finish the basement.

Latex-based paint can grow mold as well, and a plastic vapor barrier must be installed on the walls to protect any drywall or wood studs installed afterwards from mold, rot, mildew, and odors.

Instead of using a latex-based paint to protect your basement from moisture and humidity, we recommend that you use a sliane-based concrete sealer such as Concrete Treat: Concrete Sealer and Blanket.

This kind of concrete sealer will penetrate deep within the pores of the basement walls, where it reacts with the concrete to create a glasslike silicate bond.

This bond will create a moisture barrier on your basement walls and floors that will never chip or flake off, protecting your basement from damage on the long-term. Concrete Treat is colorless, nonhazardous, and can be applied easily with a brush, sprayer, roller, or by any other means. Once applied, it can be painted, and it will protect your drywall and wood studs from mold, rot, and decay caused by water vapor passing through the concrete.

To purchase Concrete Treat, check out or online store, or contact us for distributor prices. You may also contact us online, through comments to this post, or by phone with any questions you may have.