Ever year, North American commercial property owners spend an estimated $2.4 billion on remediation of concrete slabs and floor coverings as a result of moisture-related flooring failures. An additional $1.2 billion is spent on topical moisture treatments in order to address moisture issues prior to floor covering installation. However with advance planning and proper concrete moisture testing procedures, along with effective, proactive communication with the project team, expensive project delays and other unplanned expenses can be avoided.This page on concrete moisture testing offers an overview of the information needed to understand concrete moisture testing and develop an effective and efficient approach to moisture-related issues in concrete.
T A B L E O F C O N T E N T S
1. What is Concrete Moisture Testing?
Concrete moisture testing can be defined as the comprehensive assessment of a concrete slab with or without bonded floor covering, to determine the details of the environment surrounding it, such as whether a moisture barrier is in place, as well as the RH, pH, and vapor emission rate of the slab.
Information regarding the environmental details, such as whether or not a vapor barrier was installed when the concrete was first poured, help to determine the potential for the concrete to absorb moisture in the future. For example, without a vapor barrier to block moisture from below, the concrete slab is basically a sponge, and will continue to absorb moisture from the soil.
The RH, pH, and vapor emission rates all indicate the amount of moisture within the slab core.
All of these indicate the suitability of the concrete for floor covering installation. Concrete moisture testing can also be used to determine the potential for a flooring failure in the future.
Whether it’s pre-installation testing or diagnosing a flooring failure, concrete moisture testing is a specialized field that requires expertise and in-depth knowledge of concrete science, moisture mitigation, and flooring materials.
There are several different types of tests that can be conducted to assess the amount of moisture in concrete, and a professional knows which tests are necessary and appropriate for the specific job. (Back to top)
2. Why is it necessary to test the moisture in concrete slabs?
Have you ever tried to put a bandage on your skin while your skin is still wet? If so, then you know that the bandage won’t stick -- it becomes loose and falls off. The same thing happens when you place a floor covering on concrete with too much moisture. If the concrete will be the foundation for a floor covering such as vinyl, wood, linoleum, or tile, then the slab has to be dry enough so that an adhesive can be applied to it, which then bonds the flooring to the concrete.
Importantly though, moisture in concrete rises from the bottom up, and is then absorbed into the air above the slab. But when flooring is placed on top of a concrete slab, the moisture has no means of escape. It rises to the highest point it can, and then collects there.
All flooring manufacturers have published guidelines regarding the moisture tolerances for their specific products. Therefore, it’s necessary to test concrete before applying flooring, in order to ensure that the tolerances are met, and the concrete is in the appropriate condition for the application of the flooring that will be installed.
Concrete moisture testing ensures that the warranty requirements have been met, and also provides the highest level of protection from a flooring failure. Our experience has led us to the conclusion that the more information learned about any concrete subfloor, the greater the chances for a project’s success. (Back to top)
3. When is it necessary to test moisture in concrete slabs?
Concrete moisture testing is an important element of any new construction project, any remodel project, in the case of a flooring failure, or as due diligence in a potential commercial tenancy.
In new construction, concrete slab moisture test should be a requirement from the start, and should be built into the construction schedule. Proactive moisture testing ensures that the flooring installation will be successful the first time, and that the flooring will maintain its integrity over time.
It may be tempting to skip moisture testing if the existing floor does not appear to be affected by concrete moisture, but this scenario has lead to many costly flooring failures that could have been avoided with moisture testing. In a remodel project, moisture testing also offers valuable information that can be used to choose the materials that will have the highest probability of success in that location.
Concrete moisture testing is necessary to determine the specific cause of a flooring failure, and mitigate the risk of another one. IFTI’s forensic consulting team is able to diagnose any flooring failure in North America, and provide the solution that is best for the specific location.
Typical lease language requires that the landlord be responsible for the building shell, which includes the concrete slab. On-site audits will provide detailed information regarding the existing slab and flooring, and all observations made during these audits can be compiled into a report with photo documentation. This protects both the owner and future tenant from liability issues. (Back to top)
4. Best practices in concrete moisture Testing Methodology
IFTI’s concrete moisture testing professionals have been conducting concrete slab moisture tests for over twenty years. By performing and perfecting the process of investigating and assessing flooring, we’ve established protocols that save money and time on flooring installations and flooring repairs. The detailed information we provide also protects our clients from unnecessary future costs due to flooring failures or voided warranties.
Best practices in concrete testing methodology includes:
- Site background check to assess the building condition, including whether or not a moisture barrier is present
- Specifications review and rewrite (if necessary) to clarify the scope of testing necessary for each project, who will be responsible for the testing, and next steps based on outcomes of testing.
- Collaboration with other project team members to create a timeline that involves all parties
- Full documentation of testing in high-resolution photos and in writing
- Complete report of all tests and findings, with recommendations for next steps
For more detailed information on IFTI’s concrete moisture testing methodology, click here. (Back to top)
5. Tests used to measure moisture content in concrete
ASTM F710 defines the Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring. In this standard, the first step is to find out how much moisture vapor is emitted from a concrete slab. There are two methods commonly used to measure the moisture vapor emission rate (MVER) from a concrete slab. Both methods can be used with on-grade or above-grade concrete slabs.
Qualitative vs quantitative tests
First of all, there are several types of concrete moisture tests, and the test methods used to measure moisture in concrete are either qualitative or quantitative.
The most common qualitative method is the plastic sheet test. This test method involves taping an 18-inch ( square of polyethylene film onto a concrete slab and waiting at least 16 hours. Afterward, the underside of the sheet is examined for signs of moisture. Any moisture condensation or darkening of the color of the concrete underneath the sheet means that there is excessive moisture and the slab is not ready for a moisture-sensitive floor covering.
However, while qualitative test data provides a general indication of the moisture content in concrete, quantitative tests produce numerical data. Both types of tests can provide useful information; however qualitative tests should not be relied on to make a final determination of whether the concrete moisture level is acceptable for the application of flooring.
Why? Because a qualitative test that does not indicate excessive moisture can lead to the assumption that the concrete is dry enough to receive flooring. However, this test by itself isn’t enough. It must be followed by a quantitative test in order to validate the assumption that the floor is in fact acceptably dry. What’s important to know is that qualitative tests usually don’t give false positive results, but can possibly give misleading negative results.
Below are the different types of quantitative tests used by concrete moisture testing professionals:
- ASTM F1869 - Moisture Vapor Emission Rate Testing
ASTM F1869, the Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride measures the amount of moisture vapor emitted at the surface of a concrete slab. ASTM F1869 measures the moisture vapor emission rate (MVER) in terms of pounds of water per day per 1,000 sq. ft. of floor area. ASTM F710 recommends an emission rate less than 3 pounds per day per 1,000 sq. ft. for the installation of resilient floor covering.
Because ASTM F1869 measures the moisture in the top 1⁄4" of a concrete slab but does not measure the moisture deep in the slab -- moisture that could potentially reach the surface, this is not an acceptable method for measuring the moisture vapor transmission rate in lightweight concrete slabs.
- ASTM F2170 - Relative Humidity Testing
Relative Humidity (RH) testing: ASTM F2170 Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes. Testing with this method will provide valuable information about how much moisture is within the concrete. Detection of concrete moisture levels only at the surface of your concrete does not provide an adequate assessment, which is why it typically makes sense to test for relative humidity (RH) near the center of the slab.
Since flooring manufacturers specify guidelines for pH, it is also critical to know if your concrete is within these specifications in order to avoid flooring failures or expensive flooring installation mistakes.
pH Testing: ASTM F710 Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring. This test method measures the concentration of hydrogen ions within an aqueous solution. Both high concentrations (acidic) and low concentrations (alkaline) are known to negatively affect the viability of flooring and adhesives. (Back to top)
6. What is ASTM?
The American Society for Testing and Materials (ASTM) develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. ASTM standards are a critical element of product testing and quality control systems. ASTM consistently updates and modifies its standards based on current technology and industry trends. All of IFTI’s field technicians are required to maintain the most current standards for concrete testing per ASTM guidelines. (Back to top)
7. Moisture testing vs moisture mitigation
Concrete moisture testing provides an in-depth assessment of the moisture conditions within an existing concrete slab. When the moisture content of a concrete slab is higher than the required level according to the flooring product manufacturer’s warranty, moisture mitigation is often recommended. Moisture mitigation is achieved by applying high performance adhesives, coatings, reactive penetrants, or coatings -- all of which can be costly and time consuming.
Concrete moisture testing can provide the information necessary to determine whether these expensive mitigation products are the best solution for the specific location. (Back to top)
8. Costs related to concrete moisture testing
IFTI creates a custom estimate and proposal for every job we take on, based on the size of the building, whether or not flooring is in place, the type of issues we will address, and many other variables. However, a baseline cost for testing is 15 cents per square foot.
What does concrete moisture testing cost compared to moisture mitigation or a flooring failure?
Here is a breakdown of costs, comparing concrete moisture testing as a proactive step in the process, to the cost of moisture mitigation or a flooring failure:
|Removal of Failed Flooring
|Application of Moisture Mitigation
|Installation of new flooring
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9. Best Concrete Moisture Testing Companies
The best concrete moisture testing company is the one that can guarantee the highest level of professionalism and accuracy in testing. This means that the company has systems in place to:
- identify the testing needs specific to the individual site
- coordinate scheduling and specifications
- deploy field technicians (to multiple sites, if necessary)
- communicate with key team members
- produce independently verified test reports
- offer unbiased product recommendations
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10. What Makes IFTI Different?
1. Our nationwide network of field technicians
Our technicians are certified through Flooring Consultants Inspections Training Services (FCITS), which delivers us a nationwide network of certified concrete slab moisture testing technicians who can be deployed to job sites across the US and Canada. These IFTI- certified professionals are backed by a dedicated team equipped with experience, education, and a can-do attitude to ensure we deliver timely, accurate information and risk assessment solutions.
2. Our collaborative approach to concrete moisture testing
The IFTI team is a valuable addition to any flooring-related project team. Our account managers can provide timeline coordination with other members of the team, so that projects stay on a clear timeline, saving both time and money.
3. Specifications review and rewriting
Our project management team includes experts who can review project specifications, and if necessary, rewrite them in a way that provides clear and specific guidelines for the timing of testing, who is responsible for the testing, and the different plans that will be implemented based on the resulting test data.
4. Training and Certification
Before 2010, when the International Concrete Repair Institute, (ICRI) began a certification program of its own, IFTI was providing the only training available for professional concrete moisture testing technicians. Still today, every IFTI field technician is trained in the most current systems and concrete moisture testing procedures through our internal training system, which exceeds industry standards.
In any industry, third party performance testing eliminates any potential conflicts of interest. Concrete slab moisture testing is no different. As independent, third party flooring inspectors, we don’t have a financial stake in the game. We don’t sell products; we provide information -- information that can prevent flooring failures or prevent the need for expensive moisture mitigation systems.
6. Cost-efficient: Concrete moisture testing in itself is the most cost-efficient means of ensuring that your flooring project will be done right, on time, and with little or no risk of a flooring failure. Our team is dedicated to providing detailed information that will allow you to make informed decisions. Based on the needs of your project, our recommendations will include the full range of possible action steps to mitigate the risk of flooring failure at the lowest cost possible for the project. We pledge to offer only the best solutions, and never any unnecessary ones.
IFTI’s specialization goes far beyond the concrete moisture testing itself. As one of the most experienced moisture testing firms in the country, we have experts on staff that can provide recommendations based on the specific needs of each location and customer. Whether you need help selecting products, recommendations on testing scope, or recommendations on moisture mitigation products, IFTI can help find a solution that’s appropriate for your needs.
While others in the flooring industry may not be aware of all of the products on the market, or may favor a product that affords them the highest margins, IFTI offers cost-effective recommendations based solely on product performance.
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11. Reasons why an independent concrete moisture testing company is recommended:
- A flooring contractor might benefit from having high moisture in the concrete, as it could allow them to suggest a certain product, which would in turn increase their profit on the project. As an independent testing firm, our only interest is getting the correct information and exceeding your expectations.
- As stated in a position paper by The Floor Covering Installation Contractors Association (FCICA), “flooring contractors can’t be expected to determine such critical points as the chemical composition of concrete due to moisture content, alkalinity, or the effects of various admixtures on the concrete itself.” FCICA therefore, recommends an independent specialist as a safeguard for general contractors, owners, and architects.
Please do not hesitate to connect with us if you have any questions. Call (800) 490-3657 to speak to one of our experts or complete our contact form and we will connect with you as soon as possible. (Back to top)
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