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Moisture & Flooring ” Problems, Causes & Solutions
Technology 17 years ago No Comments

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contributed by Claudia Lezell, SSI, CTC, RFI, SCI, CWFI, ASID [instructor, The Flooring Technology Institute / interior designer / industry overachiever]


As annual insurance claims due to moisture-related flooring failures and conditions have soared into the billions of dollars (yes, that’s with a “b”), many design professionals are seeking to MoistureProb-title.gifbetter understand the cause of the problems. Health concerns have surged to the forefront of our litigious society, making it more critical than ever to learn what has happened to accelerate these situations to such an alarming rate.


While multi-million-dollar individual claims are not uncommon, one example that comes to mind cost the architect’s errors and omissions insurance carrier $1 million to settle out of court to avoid a potential $10 million lawsuit. All this occurred because of inadequate specifications and poor construction practices that resulted in mold growth throughout the building due to severe moisture intrusion through the concrete. This caused every type of flooring material in a 100,000 square foot building to fail. (To put it into perspective, that’s almost the size of two American football fields. Yikes!)

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Problems And Causes

Flooring and concrete-related products have changed over the years, and this has lead to each industry blaming the other for the increase in flooring failures. Due to EPA regulations, both industries have had to change with regard to manufacturing and disposal. These charges have resulted in significant performance and compatibility issues. In the case of flooring and concrete, some of these changes include asbestos, trichloroethane, volatile organic compounds (VOCs), environmental restrictions, outdated guidelines, and more.

By the middle of the 1980s, the majority of floor covering manufacturers ceased using asbestos in their products. Asbestos is no longer used in building products because of environmental and health concerns. Industry experts continue to debate on the subject regarding flooring materials that contained asbestos versus the newer flooring materials to their tolerance of excessive substrate moisture vapor emissions.

In the mid-1990s the use of 1,1,1 trichloroethane was curtailed in adhesives due to environmental and health concerns. As a result, modifications and changes to adhesives have occurred.

VOCs combine in the atmosphere with other chemicals to form ground-level ozone. The Federal Clean Air Act Amendments of 1990 gives the EPA authority to control VOC emissions for products. In 1999, the MoistureProb-3.jpgEPA mandated a reduction in VOC levels for consumer products. For the concrete industry, the EPA ruling on VOCs affects the following materials:

  •      Form release agents.
  •      Curing compounds.
  •      Dampproofing materials.
  •      Wall and floor coatings and primers.
  •      Membranes.
  •      Sealers.
  •      Water repellents.


For the flooring industry, these products are affected:

  •      Adhesives.
  •      Seam sealers.
  •      Manufacturing processes.
  •      Maintenance products.


Environmental restrictions
have also imposed stringent rules and regulations concerning emission of kiln gases and fines into the atmosphere. This has led to some alterations in the composition of cement, eventually affecting the properties of concrete. Due to high demand, the industry is engineering products from various resources (e.g., younger and older trees), but failing to remember that these products are still made of materials that respond to temperature, humidity, and/or moisture.

Other situations impacting successful builds have more to do with the human element. Some are:

Fast-track construction and value engineering driven by time and budget only and not taking into regard any of the issues addressed in this section.

Poorly staged installations due to fast-track construction and getting on and/or laying the floor covering too early, before the adhesive or setting materials have had a chance to dry effectively.

Poor acclimatization or, worse yet, no acclimatization of the building during the construction and during the moisture testing process, leading to potential dew point conditions at the concrete surface during installation.

Not appropriately protecting the concrete from the top (roof) and bottom (vapor barrier / retarder), allowing the concrete to be rewetted from the top and bottom, resulting in moisture-related issues (even years after placement).

Poorly written specifications; misunderstanding, misapplication, and misinterpretation of recommended industry standards, guidelines, and procedures; incompatibility between CSI Division 3 (concrete) and Division 9 (flooring) specification (e.g., flatness / levelness criteria).

Poor communication between the members of the chain of responsibility including the flooring and adhesive manufacturer, design professional, landscape designer, general contractor, concrete subcontractor, flooring installer, flooring maintainer, and owner.

Various conflicting terminology, methods, and recommendations used for quantitative and qualitative moisture testing.

Lack of or incorrectly executed concrete pH and moisture testing.

Installing a floor (although test results indicate different) that cannot – or should not – be installed due to elevated moisture vapor emission rate and/or pH levels.

Potential of mold growth from concrete related concerns and/or moisture intrusion into the building envelope.

Not allowing for the proper expansion for products that change dimensionally due to thermodynamics and structural movement.

Mixing dimensionally unstable flooring products together without honoring to contraction and expansion characteristics.

Poor maintenance and/or lack of maintenance, resulting in accidents.

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Solutions

The solution to moisture-related problems begins at the design stage. A client’s health, safety, and welfare must lead the design team to make every effort to make informed choices based on the most current and reliable information available. Unfortunately, due to all of the real world problems, many decisions end up being made solely on the basis of schedule or cost. Statistically speaking, the cards do not favor such an approach and often lead to failures that end up costing many times more than what was thought to be saved.

Here are a few tips to help make educated choices:

Write the specification based on the most current industry documentation and guidelines. Remember: If these standards and guidelines are not written into the specification, even thought the industry recognizes them as being “applicable standards,” your document will not be considered a complete specification.

Do not rely on outdated specification resources. Call to make sure you are using current data that is applicable to the product you are going to specify.

Thoroughly read and be sure you understand every standard and installation guideline before specifying a product in order to determine if it is applicable for that particular application. Also, pay attention to the kind of environmental and installation criteria needs that must be met before, during, and after the building process.

When considering an alternative specification suggestion, make sure that you are comparing an apple to an apple.

Use suitable products for the type of application and stage the job appropriately if a project is to be fast-tracked and value engineered due to cost and time. Also, ask how much time are you really going to buy and what potential costly damage is risked by doing this fast-track procedure. Where are the savings in the end” It is not worth eliminating something like a vapor barrier / retarder because your client just doesn’t want to spend the money.

Have the concrete tested for moisture and pH by an independent resource and/or laboratory in accordance with testing standards and applicable manufacturer’s recommendations.

Ask the manufacturers questions such as: “Do your products meet testing standards written by the industry”” and “How were they met””

If possible, get an installation and performance history on products new to the market.

Have all members of the chain of responsibility attended some of the design team meetings” If so, consider the information they provide from their area of expertise. If necessary, bring in an independent consultant who specializes in flooring, substrates, and/or concrete.

Be certain that the installers are appropriately certified, trained, and have verifiable years of experience.

Protect the job site as much as possible. Studies have shown that the vapor emission levels in concrete are affected by improper water / cement ratio, by rewetting of the concrete from rain, and/or lack of protection from beneath by a vapor barrier / retarder.

Pay close attention to the concrete specification with regard to appropriate water / cement ratio, air content, unit weight, non-reactive aggregate, compressive strength, slab thickness, and surface finish. Some floors may require different concrete finishes and a hard steel trowel finish may not be appropriate. Also look at wet cure as an alternative to curing compounds and make sure to protect the concrete from result of rain. Most importantly, for on- or below-grade slabs use a vapor barrier / retarder as specified in the ACI 302 Index and following the ACI 302/360 specification documents.

Lastly, consider using dehumidification and drying technologies as an alternative during the construction process. Not only does this help with the drying of all of the building products and significantly reduces the chance for mold growth, but it also provides a comfortable, productive work environment for the trade workers. Due to the various changes in materials, the drying process has changed for many setting products and, when placed in an unacclimatized environment with varying relative humidity and temperature (sitting at potential dew point), some products may never dry. In these cases, floor failure and potential mold growth is virtually inevitable. Trafficking a floor too early can also cause products to debond and/or indent. Also, it is much healthier for the environment and HVAC unit to have it turned on for the first time after construction and after the subsequent dust has settled down.

Note: Excluding the photos, a version of this article first appeared in the Nov/Dec 2003 issue of Texas Architect magazine. Despite a few years having passed, the subject matter is extremely relevant today. To learn a little more about Claudia Lezell and decipher her alphabet soup of appellations, please see her other article, “Floor Covering From Foundation To Cover.”

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