How to Dry Water under Vinyl Plank Flooring? | Floor Techie

Got ridges and bubbles forming on your vinyl plank flooring or is it just discoloration and deteriorating adhesive, and seams? Or maybe, the vinyl floorboards are lifting at the edges. If you’ve noticed any of these issues on your vinyl surface, you’re probably dealing with a water moisture damage issues. But, how do you dry water under the vinyl plank flooring?

Water moisture is one of the worst enemies to deal with, however vinyl plank flooring is water-resistant. In case of flooding, remove the plank flooring and ensure the subfloor remains completely dry before reinstalling your plank back. If plumbing issues, leakages, crawlspace, and groundwater moisture, you don’t have to remove the planks, repair the water moisture source and turn a dehumidifier and fan on immediately. Always wipe the accidental spills as soon as they happen to avoid expensive repair undertaking later.

In this blog, we discuss how water can penetrate through vinyl planks and end up underneath the flooring. We also go through signs of moisture under vinyl flooring and how you can remove this moisture and prevent the same from happening in future.

How to Dry Water under Vinyl Plank Flooring? Signs of moisture under LVP flooring

Can water get through vinyl plank flooring?

No- both glue-down and click-lock vinyl flooring are waterproof. That’s why luxury vinyl tiles are a great flooring option for wet areas such as bathrooms, kitchens, and indoor pool rooms. Still- water may end up underneath your vinyl floorboards if the seams and perimeter aren’t well-sealed. Such moisture can also cause mold to grow beneath the vinyl planks.

In glue-down vinyl, water can seep through the seams if they weren’t properly sealed and wash out the adhesive attaching the planks to the subfloor. This results in lifting along the edges of some of the floorboards. For floating LVT flooring, water cannot penetrate through the click-lock system. However, if the edges adjoining the walls aren’t properly sealed, water can still get through and end up underneath the vinyl floor.

Moisture problems on vinyl flooring can worsen if you live in a region where it snows during the winter months. This is because as house occupants walk in, their shoes/boots may introduce snow alongside rock salt. These ice melters are highly alkaline and break down the adhesive sealant between adjoining planks. This then makes it easier for water to seep under the planks through the open seams.  

Signs of moisture under LVP flooring

Signs of moisture under LVP flooring. How to Dry Water under Vinyl Plank Flooring?

Whether it’s glue-down or floating vinyl, the floor may start lifting due to moisture buildup underneath the planks. Check around the edges of the planks for signs of lifting. Also, if you have bubbles forming in the middle of the vinyl floorboards, then you definitely have moisture under your floor. Other signs of water damage on vinyl flooring tiles include warping, buckling, and discoloration.

If your subfloor is made of wood and you suspect your vinyl floor is buckling or lifting due to a wet subfloor, you can check for signs of moisture in the crawlspace. Moisture usually promotes the growth of mold on the floor joists. Thus- if the joists are mold-blackened or water is dripping from them, you need to dry out your subfloor.

If the vinyl floor is on the upper-story, you can check for signs of moisture in the rooms beneath it. For instance, even your best DAIKIN Wall-Mounted Ductless Mini-Split A/C Heating and Cooling System may get faulty and start letting out humid air, or there may be a leaking pipe in the room.

Another indicator of moisture underneath your vinyl floor is the growth of mold under the planks. These fungal organisms release toxins into the air, which can trigger respiratory diseases. You can test for mold growth under your vinyl surface using a mold test kit. Mold also bears an earthy and musty smell.

If you have a concrete subfloor, you can remove a few of the vinyl planks to test the subfloor for the presence of moisture. Tests can be undertaken using tools like the Delmhorst Moisture Detector or the RMA Moisture Test Unit. If you don’t have access to such test equipment, simply place a rubber mat on the part of the floor where you removed the vinyl to reveal the concrete subfloor. Let the mat stay in place for 24 hours. If the bottom of the mat is damp/wet afterward, then there’s moisture in your concrete subfloor.

How to dry water under vinyl plank flooring

If the potential for water damage is extreme, say, after flooding, you’ll need to uninstall the vinyl floorboards to dry out the subfloor. You can remove glue-down vinyl off the subfloor using a floor scraper such as Warner 5″ Heavy Duty Floor Scraper. However, if you have very old vinyl, it may contain asbestos. In such cases, avoid uninstalling the vinyl yourself and call in the pros.

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After removing the planks, you can then remove most of the water on the subfloor using a shop vac; DEWALT Vacuum (DCV581H) as a water extractor or a mop and a mop bucket such as O-Cedar EasyWring. You can then run Midea MAD20C1ZWS dehumidifiers and Lasko 2511 36″ Tower Fan in the room to dry out any remaining moisture.

Once the floor seems dry enough, test the moisture levels using a General Tools MMD7NP Pinless digital moisture meter. If it’s adequately dry, you can proceed to reinstall the vinyl floorboards. If not, continue drying the subfloor some more before replacing the vinyl planks. Remember, while it’s possible to reinstall click-lock vinyl planks, you may have to call in an expert to reinstall your glue-down vinyl planks. Also, not all vinyl planks can be reinstalled. You’ll need to replace the ones that were lifted at the edges or warped due to water damage with new vinyl planks.

Meanwhile, if you have a moisture problem but it isn’t as a result of flooding, you don’t have to remove the vinyl planks. Instead, simply turn on the heater and some fans in the room to dry out the moisture. For medium-large-sized rooms that are damp, a dehumidifier is recommended. Some dehumidifiers can extract up to 22 pints of air moisture every 24 hours.

Finally, if the water damage is due to plumbing leaks in pipes running through your crawlspace or basement walls, ensure to seal these leaks. If your faulty HVAC system is letting out humid air, ensure to make the necessary repairs.

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Ways to Prevent Moisture and Mold Under LVP flooring

Moisture prevention under vinyl flooring starts with proper installation of the vinyl flooring tiles. The installation contractors should check the moisture levels of the subfloor before installing the vinyl planks.

You can also prevent future moisture problems on vinyl flooring during the construction stage of the concrete subfloor. To prevent moisture-related issues, you should:

  1. Maintain a low water-cement ratio – with more water in the mix, the slab won’t dry as much as it should before installation of vinyl over it. You should also avoid adding water to your existing concrete mix.
  2. Ensure proper water displacement – this is especially crucial if you’re building the concrete subfloor at a wet building site. This may include the installation of extra draining lines and the use of water extraction pumps.
  3. Allow enough time for the concrete slab to dry and cure– rushing to install vinyl tiles over a concrete slab that’s not properly cured will likely lead to moisture problems down the line. You should consider reviewing your project timelines to allow enough time for drying and curing. If not, you can try to accelerate drying by adding a dehumidifier to help soak in moisture from the concrete.
  4. Use of a vapor retarder– a vapor retarder sits between the grade and the subfloor to prevent runoff water from rain, snow, and sprinkler systems from penetrating into the porous concrete slab.

If your subfloor is made of concrete, it likely has a high alkaline content. While the alkaline levels in concrete usually drop over time; in certain cases, this doesn’t happen fast enough, resulting in adhesion failure. Consequently, water can seep more easily through the non-sealed seams of the LVT flooring. That’s why it’s important to test the pH levels of your concrete subfloor prior to installing vinyl flooring.  Alkalinity tests can be done using a pH test kit that contains pH indicator strips. After letting distilled water sit on the concrete slab for about a minute, insert a pH strip into the water. You should only proceed to install the vinyl floorboards if the reading is below 9.

You can also take preventive measures to seal out moisture. This includes installing underlayment between the subfloor and the vinyl flooring to act as a moisture barrier. Most luxury vinyl tiles come pre-fitted with underlayment foam beneath, but adding an underlayment can provide extra moisture protection. Meanwhile, for vinyl flooring installed in toilets, ensure to properly seal out possible sources of moisture infiltration such as the herkle ring using a silicone sealant.

Finally, you can also prevent runoff water from soaking into the grade around your slab by installing gutters on your roof. These will lead water away from your house. Meanwhile, to prevent mold growth due to the presence of moisture beneath the vinyl flooring, we recommend investing in vinyl planks that contain mildewcides.

Related:How to Stagger Vinyl Plank Flooring, What Is Vinyl Flooring Made of?, Vinyl Flooring in Bathroom: Pros and Cons, is it Good?, Is Vinyl Flooring Toxic?

Source and References

Bulding Science: Understanding Vapor Barriers?

Energy Savers: Vapor Barriers or Vapor Diffusion Retarders Moisture Barriers?

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