Why Concrete Moisture Is a Problem and How You Can Fix It

concrete surface

Concrete surfaces are tricky. As we all know, water is a vital component of any concrete mix. Given enough time, newly poured concrete will dry out enough during the curing process to make way for the next step in construction.

Here lies the problem: after the slab has cured, it can appear free of moisture even when it’s not. The moisture on the surface might have evaporated. But the one below or within the concrete is transferred upwards through the capillaries. This behavior is known as moisture vapor transmission (MVT).

Now, MVT is terrible news. It can lead to several flooring issues. The lamination and bonding can fail, the floor covering can crack and bubble, and the walking surfaces can become uneven, leading to slips and falls. Not to mention, the concrete substrate and flooring material will prematurely deteriorate.

Concrete science is far from perfect; the industry doesn’t have all the answers. But the signs don’t lie. If you spot any of these issues, it’s a clear indication that your flooring has started developing moisture problems.

Signs to Look Out for

  • Damn spots on the floor
  • Darker areas on the surface indicating discoloration
  • White residue coating implying salt deposits from moisture
  • Visible signs of delamination and loose pieces in tile flooring
  • Lifting, cracking, bubbling, or peeling of the floor surface
  • Black stains on the floors or walls
  • Mildew or a musty odor in the room

If you’ve identified any of these issues, it’s time to perform moisture vapor testing. You can do it yourself or hire a professional to do it for you.

3 Tests to Check for Moisture

Prevention is better than cure. Ideally, you’d want to check every slab for moisture before installing the floor covering and using a quality waterproof epoxy system. But late is better than never, so here are three ways to test the moisture level in your concrete flooring:

Concrete Moisture Test

  • Stick an 18 square inch piece of plastic onto an exposed concrete
  • Leave it for 16 hours

If you find an accumulation of moisture under the plastic after 16 hours, then it could mean excessive moisture in the concrete.

Calcium Chloride Test

  • Buy the Calcium Chloride Test kit
  • Measure the weight of the calcium chloride and see if it increases after three days

It doesn’t only reveal the presence of moisture but also indicates the quantity and rate of moisture migrating upwards through the slab. Its scope is limited to the moisture in the top 3/4th inch of the piece.

Relative Humidity Testing

This test is the most comprehensive and most advanced of the three methods. It is done via specialized moisture probes inserted into the concrete substrate, indicating the presence and quantity of moisture of the whole slab.

Addressing Concrete Moisture

gray concrete slab

Repairs can be costly, but they’re a necessary investment to keep your flooring operational and safe for everyone.

  • Replace the flooring using MVT remediation systems
  • Replace the concrete slab
  • Remove and dispose of damaged floor covering
  • Inspect for mold

You also have a wide range of floor covering options to choose from. Install a quality waterproof epoxy system to ensure long-lasting moisture control to meet the performance and aesthetic expectations in your facility.

Concrete moisture is a flooring issue that can lead to major downtime, accidents, and potential loss of revenue for companies. But if you know what signs to watch out of and the ways to address them, you can make the necessary improvements before it’s too late.

Scroll to Top