Rubber & Vinyl Floor Moisture Testing

The Different Characteristics of Rubber and Vinyl Flooring


Vinyl and rubber floor products have a myriad of advantages including excellent water resistance, easy maintenance, and a natural scratch resistance. They are typically durable and long lasting and come in a variety of applications to suit almost any location.

The other advantage to vinyl floor products is that they are available in a wide range of looks and styles to compliment any décor. Vinyl flooring has increased well beyond the standard sheeting in the range of floor products available. Vinyl tile, in both commercial and standard grades, and vinyl planking are options with either locking or standard glue-down installation. Some vinyl floor products include limestone or fiber additives or backings that increase their durability and chip resistance or offer more cushioning underfoot.

A good example is flex flooring, a product made to go over existing vinyl flooring. The combination of polyurethane top layer and fiber backing give it better flexibility for both installations and for comfort.

Rubber flooring provides a slip-resistant surface that holds up very well under heavy foot traffic. It can be purchased with a number of designs, colors and patterns for an easily customized look suited to either home or industrial use. Textures like round stud or diamond grip increase the traction level of foot traffic while still having an industrial-standard resistance to wear and damage. Rubber flooring is available in either tiles or sheets and can be applied with glue, for a movement-free flooring, or as “loose lay,” attached with double-sided tape for quick removal if required. Rubber tiles are also available in interlocking styles for adhesive-free applications over a variety of surfaces.

Because both vinyl and rubber floorings are naturally impervious to water, it would seem that moisture testing for rubber or vinyl flooring applications might be unnecessary. But the cost of moisture-related problems can be just as high even with these seemingly “moisture proof” floors.

How Can Moisture Cause Problems with Rubber and/or Vinyl Flooring?

The real problem for vinyl and rubber flooring is often in the subfloor, or in giving moisture access to the subfloor. Moisture can impact the flooring in two locations:

  1. Seams (if there are any) – Tiles and planking in either vinyl or rubber styles will naturally contain more seams in a finished floor. In a loose-lay or floating installation, those seams provide spaces for moisture to seep down through the seams and either enter the subfloor or sit between the subfloor and the flooring affecting both the product, the subfloor and the adhesive used to connect the two. In a fiber-backed product, it is easy to see how this can also cause warping, buckling, swelling or even lead to mildew.
  2. The subfloor itself – Because rubber and vinyl products are so well suited to damp or humid conditions, they are often applied directly (or indirectly) over concrete or other sub floors. But if that subfloor is not dry to acceptable levels, the reality is that product and/or adhesive is at risk of a flooring failure.

Moisture Prior to Installing Rubber and/or Vinyl Flooring

Moisture, particularly in a concrete slab, can come from a number of sources. If the slab does not have an adequate moisture barrier underneath, moisture can wick up from ground sources in a continuous cycle. And any existing slab can still be subject to moisture intrusion if it is in contact with leaking plumbing or irrigation systems, ground moisture or excess humidity in the environment. In a new slab, if the concrete has not dried internally to the levels acceptable for the particular flooring and/or adhesive used, moisture will continue to work its way to the surface under the applied flooring. (Explanation of the process of moisture movement in a drying concrete slab)

For any flooring installation, adequate moisture testing is imperative. For a concrete subfloor, relative humidity (RH) testing is the best way to get a true picture of the moisture conditions within the slab to prevent any negative moisture impact to the finished floor. The ASTM F2170 recommends in situ probes for RH testing. Test methods like the Rapid RH® L6 provide fast and accurate test results within the subfloor so that any issues can be remediated before putting the flooring at risk.

When installing a rubber or vinyl floor, moisture testing is just as, or even more, important than it is with any other flooring product. Because where the rubber meets the road, moisture can still jeopardize your installation.

Last updated on December 4th, 2020


  1. Andrew Kester says:

    I am a forensic and structural engineer, and I inspect buildings for a variety of problems including flooring damage throughout Florida. Moisture damage to flooring is one of the most common issues I see. Concrete slabs are permeable and actually transport vertically and horizontally due to capillary action, think of concrete as swiss cheese. A vapor retarder membrane is required by the Florida Building Code underneath the slab, but the required thickness is too thin in my opinion, and the result can be a damaged membrane that allows moisture into the slab. Unless you live in a desert area, there is always moisture in the soil trying to get into the slab.

    I often see flooring problems where new laminate or vinyl flooring products are applied over top of existing hardwood flooring, both on concrete slabs and on wood subfloors elevated above crawlspaces. The new flooring acts a vapor retarder preventing the moisture within the hardwood flooring from evaporating. Sometimes these are 50+ year old houses that never had a flooring problem until the new flooring was installed. With crawlspaces the situation can be devastating, I have seen entire subfloors completely decayed forcing the interior of the house to be gutted.

    To answer Karen’s question above, this certainly can occur without any evidence of moisture problems, because the wood could dry out enough not to have noticeable problems:
    “If there was moisture coming from the slab we certainly would have seen the discoloration or deterioration of the wood.”

    “The company pulled them up and told me there was moisture trapped under the parquet. The parquet was absorbing the moisture and buckling since the Cortec was vinyl and trapping it. ”

    The company was correct, and they should have known this beforehand, and refused to install that product over top of existing wood flooring.

    If you have a concrete slab floor system, I would not recommend installing anything over wood flooring, just pay the extra money to have it removed first. The only exception is carpet, which is not very popular anymore other than bedrooms (in Florida). And this presumes all carpet is vapor permeable, I don’t know much about carpet…

    If your floor system is a wood structure over a crawlspace, I would be very careful before installing any new flooring. You want to make sure your crawlspace is relatively dry and there are no current moisture issues with the wood subfloor and beams.

  2. Jeremy says:

    I recently had a fair amount of water get in after an external pipe burst. I’ve been using a moisture indicator to ensure everything has dried completely, and to identify what had to be removed. Everything is straight forward on how to measure different woods, concrete, and drywall. My question is: Can I use a moisture indicator to check that laminate or vinyl flooring is in a safe range? Or do I just need to wait for visible signs of damage? I’m not sure if the reader can be used on vinyl. I do know that I get the same readings on all vinyl flooring throughout my home. Even areas that did not get wet. Sorry about the length, and thanks so much for your time.

    • Jason Spangler says:


      Thanks for the question. Part of your question revolves around the quality of the moisture meter you are using. Some are going to perform better than others. On most installed floors that have suffered water damage as you describe, a good non-invasive meter will be used to give relative information, not absolute. Meaning, with the thickness of the floor product and the depth of the measurement scan, there is an aggregate reading between both surfaces. The nice thing here is that you can take a good meter and measure in areas that aren’t affected (using the results as a baseline) and rapidly scan towards the affected area, identifying suspect areas as the numbers increase. My guess is you aren’t “really” reading moisture IN the vinyl. Good luck.

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