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Concrete Moisture Leading to Flooring Failures - Is this an Epidemic?

Sheet vinyl  lifting off concrete substrates that looks like blistered skin from a burn, wood flooring turning up at the edges, carpet tiles emitting foul odors from reactions with “wet” slabs.  All of these failures in floor covering occur daily around the country plaguing flooring contractors and end users.  Is this a flooring conspiracy or something more sinister?  Well, it’s not a conspiracy, nothing so colorful as that, and it’s not sinister unless you consider that moisture lurking in the substrates is skulking around waiting to pounce.

What are the reasons for this outbreak of flooring failures?  Have adhesives changed?  Is flooring material different?  Hasn’t concrete been the same for years?  Why is this all happening now?

Adhesives have changed from when solvent carriers were used but adhesives are actually better now.  Flooring products have changed with the onslaught of non-permeable backings which can trap moisture vapor emissions coming from concrete.  Concrete hasn’t changed much but it is finished faster and harder and this limits moisture’s ability to escape.  Most importantly, construction jobs are fast-tracked meaning the job is rushed to completion without enough consideration for the ramifications of this action.

Moisture in the concrete, missing or improperly installed vapor barrier/retarders under the slab and cycling HVAC systems to save energy are the three biggest contributors to the problem.

When changes in the internal environment of a building are caused by cycling the HVAC system, and moisture of convenience (water used to hydrate the concrete slab) tries to equalize, moisture will move from high pressure to low.  When this happens, anything in the way, like flooring, will be affected.  If the flooring material is non-permeable, meaning moisture vapor emissions are trapped and unable to escape, it will push the material off the floor.  Sheet vinyl will trap the moisture,wood will absorb the moisture; and moisture and alkalinity can affect the PVC in carpet backing and create an odor. 

Failing to place vapor barrier/retarders directly beneath the concrete will allow moisture from beneath to move upward into and through the slab affecting the flooring material installed on top of it.  Fast tracking- installation often means concrete is not allowed to cure for the appropriate length of time. Installing non-permeable flooring material on top of it is a recipe for disaster.

Installing flooring before the substrate is in the proper condition to receive it allows the laws of physics to work against you. This condition is a daily challenge to flooring installations and results in millions of dollars in claims and losses for the industry. If we keep going the way we are, paranoia will certainly accompany every flooring installation of hard backed goods.

Changes in the way flooring is installed and the materials we use have to happen and the buck stops at every level of our industry. Construction supervisors in the building industry must stop fast-tracking concrete before floor installations and specifiers have to call for moisture retarders under concrete before the epidemic will stop.

Fortunately the minds of men feed on challenges and this is certainly so in the flooring industry.  Products do exist to combat problems and make installations easier.  The advent of the new Freelay® backing and installation system, for example, allows for any carpet to be installed without using an adhesive. This system works extremely well on substrates that would typically cause installation failures by traditional means.  The EnviroStix™  installation system for hard surface flooring such as sheet vinyl, vinyl tile, LVT and vinyl plank is designed to be used on slabs that would cause an installation failure by traditional means.  Both of these new installation technologies have been proven under the harshest of conditions.  One of the things we do at LGM and Associates is test products and we have tested Free Lay for years.  I have written about it in my Claims File column that appears regularly in Floor Covering News as well as the Commercial Flooring Report published monthly.

Failure of flooring materials and their installation has reached epidemic proportions but there are ways to prevent this from happening. The technology of these systems work but they have been met with skepticism by many in the industry. The technology will prevail over the disbelief driven by the demand of the end user who, once suffering the pain of a flooring failure, will insist on it.


Lew Migliore is President of LGM and Associates, a technical consulting firm specializing in all aspects of product and installation performance and education. He is also a consultant with the Floor Covering Institute.


  1. Moisture weakens the concrete stabilization of flooring. Consulting a professional contractor should really help prevent this failure so we could avoid accidents in the future.

  2. This comment has been removed by a blog administrator.

  3. Thanks for the great post. For more great information and resources for concrete contractors...

  4. Loved going through the article! Great post! Thanks for the post!

  5. It’s good to know that this article shows that careful installing of concrete is very important. As much as possible hire professional contractor to work so that you will not end up fails. WA concrete will be helping you with this idea.

  6. So it means, it's just the cause of improper installation of floor? Thanks for your opinion about that, you really shared an important information.

  7. I have a question: Flooring imperfection due to moisture, can this really cause a certain damage when carpets are installed?

    Anyway I also like mark's statement:
    Moisture weakens the concrete stabilization of flooring.

    Thanks for sharing your nice post.

  8. Thank you for your question. Not sure exactly what you mean but flooring imperfections due to moisture in concrete would actually be the moisture vapor in the concrete causing blisters, wrinkles or bubbles due to the loss of adhesion. Adhesion loss would be from alkalinity carried in the concrete destroying the tackifier, the sticky part, of the adhesive. This isn't really an imperfection but a cause and effect condition. There are extenuating circumstances of detail. If the flooring is hard surface, such as sheet vinyl, rubber, hard backed carpet tile, etc., bubbles or blisters can form beneath the material. All of this means there is a concrete moisture issue which has to be addressed. There is certainly lots more to this but this is a fairly simple answer. Lots of physics and chemistry going on between the concrete and the flooring material.

  9. Thank you for a good article. There continues to be debate in the concrete industry as to how to prevent this. There is the issue of properly installed vapor barriers and the link to concrete curling. There is also set times and proper finishing that are to consider as well. Thanks for the article.

  10. Thank you for the information. Now I know why there are flooring imperfections.

  11. Such a nice article.
    It has a great information for concrete flooring.

  12. Good article on concrete moisture. As I concreter I know how much of a nightmare moisture can create which is why you really should leave concreting up to the professionals rather than do it yourself if you dont know 100% exactly what your doing.

  13. This comment has been removed by the author.


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