Home » Water Under Vinyl Plank Flooring (Signs & Dry Tips)

Water Under Vinyl Plank Flooring (Signs & Dry Tips)

Vinyl plank flooring is often revered for its water resistance property. No wonder it has become a flooring favorite of many homeowners. However, if constantly exposed to water for long, it can seep through vinyl planks inviting various unwanted problems, including molds.

So, if you recently noticed water underneath your vinyl plank flooring and are panicking about how to remove the moisture, you’re at the right place! Let’s dive deep and find out why does water seeps through vinyl planks and the possible solutions for the problem.

Vinyl Planks and Water Resistance

Vinyl Planks and Water Resistance

Vinyl planks are made up of Poly Vinyl Chloride (PVC) resins mixed with plasticizers, fungicide, and stabilizers. As it is not authentic wood, it doesn’t imbibe liquid or moisture as hardwood does.

Even if you soak individual vinyl planks for days in water, no major physical changes will occur within the plank. You can dry them, and they’re just as good as before. So, in short, vinyl planks are completely water-resistant.

Can Water Seep Through Vinyl Plank Flooring?

Can Water Seep Through Vinyl Plank Flooring

It is given that vinyl planks are water-resistant. Then why are there many complaints regarding the moisture build-up under their vinyl flooring?

The fact many are unaware of is that it is possible for water to seep through vinyl plank flooring via the joints between the two planks, especially if the flooring is glued down.

On the other hand, for floating floor installation, water cannot penetrate through the gaps easily. Nevertheless, if the edges of the floors are not properly sealed, water might seep through the gap between the floor and the wall.

Minor spills and water exposure doesn’t do any surface damage on vinyl flooring. But during large-scale mishaps or continuous exposure, water can sneak through from the gaps.

Moreover, another major culprit for such moisture build-up can be concrete if you’ve directly glued your vinyl planks atop concrete. Likewise, plumbing issues might also be the reason why your vinyl flooring has been compromised.

However, there are ways to decrease such sneaky incidents. We’ll discuss the tips further in this post.

Signs of moisture under Vinyl Plank flooring

Signs of moisture under Vinyl Plank flooring

There are a few ways that tip you off whether or not there’s water under your vinyl plank flooring. Let’s look at these signs briefly.

1. Lifting and bubbles:

Your vinyl plank flooring will lift up around the area of moisture build-up. Especially if the flooring is glued down, the adhesives start deteriorating upon moisture exposure. This causes planks to move or lift upwards around the edges.

Moreover, if you notice bubbles on your vinyl plank flooring, it means that the planks have moisture build-up underneath. However, such bubbles are not always visible. So, if you suspect such mishaps, make sure you run your fingers around the area to check for bumps and bubbles.

2. Discoloration:

The next big indicator of moisture build-up is discoloration or tarnishing of your vinyl planks. Cleaning your vinyl flooring system is no big hassle, and almost any stains from the flooring are removable. So, if you notice weird discoloration or spotty tarnishes, you must check under the flooring for moisture build-up.

3. Mold formation

Mold formation on compromised vinyl flooring is not an uncommon thing. Molds love damp areas. So, if you notice moldy structures somewhere on flooring, it’s time for a quick moisture build-up test.

The sudden earthy smell in the room can also indicate that mold has made itself home on your flooring. Moreover, you can also check for mold by using a bleach test. Dab some 1/16 diluted bleach onto the affected area and check for color changes. If the spot lightens, it’s mold.

What To Do When You Notice Water Under Vinyl Plank Flooring?

What To Do When You Notice Water Under Vinyl Plank Flooring

Now onto the solution: how to solve moisture issues under vinyl plank flooring? Though hectic, there are ways to solve this.

1. Check for plumbing issues

If your bathroom vinyl plank flooring has moisture problems, firstly, you need to check if there’s any plumbing or leakage problem. If you notice an increase in your water bill, there might be some leakage problem.

Check for leakage in kitchen sinks, dishwashers, bathtubs, and other leakage-prone materials. Another telling factor is dripping sounds, so keep your ears sharp. Once you pinpoint the problem, if any, solve it first before moving on to the next stage of repairing the flooring.

2. Check for other underlying issues

You don’t obviously want to solve the surface-level problem and leave the major underlying issue unchecked. So, check for any underlying issue. Issues on subflooring are also one of the major reasons for moisture build-up.

If your vinyl flooring is installed directly above concrete, a high moisture level in the concrete might be the reason your flooring is facing moisture issues. If that’s the case, you should pull out the planks and let the subfloor dry.

3. Use a mop if the entire flooring is flooded

If there’s a significant spill or flooding, make sure to mop the surface as soon as possible. Do so as many times as it takes to clear water from the surface. If necessary, clean the surface with vinyl-safe cleaners.

4. Turn on dehumidifiers, heaters, or fans

Turn on dehumidifiers, heaters, or fans for a few days over your flooring to ensure that moisture residues evaporate well. If the moisture has seeped through the gaps, take out the vinyl planks and let the subfloor dry to prevent mold invasion.

Open doors and windows for proper air circulation. But if the outdoor air is more humid and saturated, let indoor electric appliances do the job.

5. Reinstall or replace the planks

Once you’re sure the subfloor is dry and safe to reinstall your flooring, check if all your vinyl planks are in good shape. Reinstall usable planks and replace the damaged ones with some new planks.

6. Seek expert help

If the moisture problem seems out of hand, you might have to take professional help. You should dry out the moisture completely, get rid of mold spores, and reinstall or replace the flooring.

Getting rid of molds can be a real hassle. You cannot ignore its presence either, as its toxins in the room can lead to numerous respiratory issues. So, it is imperative to make sure the flooring is mold-free once the repairing and reinstallation are done.

If the entire procedure sounds overwhelming or you don’t feel confident enough, you should always hire professionals to do the work for you.

How To Prevent Moisture and Mold Under LVP flooring?

How To Prevent Moisture and Mold Under LVP flooring

We all know – prevention is better than care. To save yourself from the exhaustive drying procedure that you’ll have to follow once your vinyl flooring becomes compromised, we have gathered a few tips for you. Let’s look at them one at a time, shall we?

1. Low water-cement ratio

While preparing the concrete subfloor, maintain a low water-cement ratio to the mixture. Doing so lets the slab dry fast, thus, precluding any possible moisture issues in the future.

2. Prevent continuous water exposure

If your dishwasher or washing machine overflows frequently, try to get a hold of that problem early on. Else, the flooding water slowly breaks the adhesion between two planks, especially if the planks are glued down and seeps through the gaps over the long run.

3. Let concrete slab dry well

If you add your flooring atop the concrete subfloor before letting the subfloor cure and dry well, your vinyl flooring will face major moisture issues later on.

You can use a moisture detection kit to determine the moisture level of your subfloor, in case you have one. The ideal cement subfloor moisture content for vinyl flooring installation is less than 2.5% CM.

You can also test if or not your concrete subfloor will engender moisture issues using a mat. Put a mat on top of concrete for a day or two and check the underneath of the mat. If you notice moistness, the subfloor isn’t dry enough to install vinyl flooring.

Another method to determine the presence of moisture is to install a vinyl plank using adhesive tape. If the tape comes out easily the next day, that is an indication of a moist concrete subfloor.

4. Consider using moisture barrier

If nothing seems to work, consider adding a floor moisture barrier to your flooring. Moreover, adding a flooring underlayment also makes the floor comfortable to walk on.

If your vinyl planks have pre-installed underlayment, or if you’re installing the vinyl flooring on top of a wooden subfloor or tiles, you can skip adding a moisture barrier.


Finding water under your vinyl plank flooring can be a real headache. However, instead of panicking and solving the surface-level issue without deliberation, you should find the underlying issue and solve the problem with aplomb. Doing so will save you from similar scenarios in the future.

Moreover, don’t forget to check for any warranties for moisture damage provided by the dealer and, most importantly, seek expert help if the damage is too significant. We wish you all the best in your battle against moisture and mold.

2 thoughts on “Water Under Vinyl Plank Flooring (Signs & Dry Tips)”

  1. Do you have to have a older concrete floor sealed before having flooring laid such as vinyl floor planks..the slab house was built in the 70s ..I have had plans down for 2 years and have found my hallways have created moisture and lifting of the planks.

  2. Hi, Dealer told me that since one corner of my place got water damaged so water traveled under the SPC and or trough the concrete and caused damage, so i asked how that possible since the manufactures says 100% waterproof, He said the minimum water or the moist cause damp underneath and that caused the cupping of the SPC.
    Please explain it to me the way that i understand it too.


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