3 Things You Need to Know About Moisture in Your Concrete

What do you call the place where concrete is buried…?


The Cementary…. Okay, I know what you’re thinking. That joke was terrible and cheesy. One thing this joke and moisture in your concrete have in common? They are both terrible. Moisture causes fundamental issues with the way concrete is meant to function. It can lead to cracks, mold, and more.

Read on to learn how to recognize signs of moisture in your concrete, what all that moisture is actually doing to your concrete, and how to solve the problem!

How to recognize signs of moisture

Moisture issues in concrete floors typically comes from one of two places:
The concrete mix: it’s possible that the slab was insufficiently cured and/ or is otherwise holding in moisture.
There was a vapor barrier at one time, but it is either damaged and failing to function, or is aged and needs replacing.

Concrete is a porous material by nature, but there are certainly some signs you should be aware of and look out for to avoid problems like cracking or bubbling of surface coating, uneven surfaces, development of mold, and the subsequent failure of the concrete substrate. You might want to be on the lookout for some of these indicators that there is a moisture problem in your floor:

Damp spots or other areas of dark discoloration that you can’t attribute to some other stain (i.e paint, oil, etc.)
Are there loose pieces of tile or other materials that required grout or adhesive during installation?
Cracks, bubbling, peeling, or lifting of the floor’s surface
Black stains and/or smell of mildew or mold

Now don’t worry, sure that all sounds pretty bad, but how does water really lead to all these disastrous sounding conditions.

How moisture affects concrete?

Too much moisture, in addition to air pockets in your concrete flooring will leave you with a fragile surface. When there is more water in your concrete, it creates more space between the grains of the cement (an ingredient in the concrete). Increased levels of moisture will, without a doubt, reduce the strength and durability of your floor overtime. This happens because as the water makes those gaps bigger, they fill with air. These air pockets are what lead to fragility and instability in the concrete.

Just like any other time a pH balance is disturbed, the changing of the pH levels in your concrete can have some devastating effects. Humidity has a direct effect on the pH level in your concrete. If the humidity increases, so does your concrete’s pH and temperature. This isn’t necessarily bad but high temperatures can lead to a more porous surface- leading to problems over time. Plus, if the pH level in the concrete is too high, this is where we see adhesives fail. Additionally, acids from things like salt, cleaning agents, and other road chemicals can dissolve the aggregate in your concrete. Over time this will turn your concrete floor into a rocky, sand pit.

Last but certainly not least, if there is too much moisture in your concrete, you are going to end up with that horrible musty, mildewy smell. This occurs because, increased temperatures/ humidity + porous concrete = The ideal breeding grounds for mold, mildew, and bacteria. While it’s unlikely that your concrete will actually grow mold- due to the low amount of organic materials for mold to feed on- it does contain trapped pollen, dust, salts, etc. Those are all things that can fuel the growth of mold which comes with some subsequent reduction in the strength and integrity of the concrete not to mention, who wants to be breathing that in?

What’s the Solution?

At Paveman Designs, we pride ourselves on a thorough evaluation of a project space before we ever lay a grinder on it. Our concrete experts are well versed in measuring the moisture levels in concrete and fixing the problem. How? By using a vapor barrier. At Paveman Designs, if there are known water problems, or if we detect too much moisture in our evaluation, we will recommend the vapor barrier. This is the best way to protect your concrete and your concrete coating!

Paveman Designs can also provide cove molding. This is where we continue the floor coating a few inches up the wall. This helps give you and your floor some extra piece of mind that moisture will not be a problem and that your concrete and its coating will hold up for years to come!

Click here to download our free moisture checklist to see if it’s time to call a professional!