Many individuals within the construction and floor covering installation industries are already familiar with the moisture tests conducted before installing floor coverings on concrete surfaces. However, an increasingly important requirement that some might not be fully aware of is the need to perform substrate surface absorption and porosity tests. Regrettably, adhesive bond tests, which are either strongly recommended or even mandated by most manufacturers, often receive insufficient attention or are carried out incorrectly.
When in doubt, it is advisable to consult the manufacturer’s literature for their specific procedure for bond tests. In the absence of such instructions, ASTM F3311, titled “The Standard Practice for Mat Bond Evaluation of Performance and Compatibility for Resilient Flooring System Components Prior to Installation,” serves as a valuable resource. This relatively recent ASTM standard provides clear guidance on how to correctly conduct bond tests, and it is crucial to adhere to its instructions meticulously. Failure to do so can lead to results that incorrectly indicate a satisfactory Mat Bond Evaluation, potentially resulting in significant issues during the installation of the full flooring system, or conversely, results that indicate failure due to the omission of one or more critical points outlined in ASTM F3311.
It is essential to understand that ASTM F3311 represents a qualitative and subjective evaluation and does not provide a long-term forecast of the bond’s performance and compatibility with the multiple layers of the flooring system. The evaluation should encompass all aspects of the flooring system, including the concrete surface profile (CSP), surface preparation products like underlayments and primers, surface moisture mitigation products, and the adhesive and floor covering materials. Consideration should be given to what the floor covering product will be adhered to—is it directly onto the concrete surface or another layer between the concrete and the adhesive? All components of the flooring system must be assessed in accordance with ASTM F3311, taking into account what each layer will ultimately adhere to in the completed flooring system.
Project teams may opt to conduct the Mat Bond Evaluation weeks in advance of the floor covering installation to allow ample time for corrective measures or alternative options if the evaluation results are unfavorable. By default, this places the Mat Bond Evaluation in a non-climate-controlled environment, which is not in accordance with ASTM F3311.
But why should the Mat Bond Evaluation be conducted in the first place? While adhesive manufacturers typically specify the compatibility of their products with floor coverings and subfloor surfaces in their product data sheets, certain jobsite conditions may necessitate conducting the evaluation. Let’s explore some common issues that could interfere with or skew evaluation results:
- Dirt and Dust: Often overlooked, dirt and dust are common bond breakers and must be thoroughly removed from the surface to which the flooring system will be bonded.
- Surface Absorption: Determining whether the surface is absorptive or non-absorptive is crucial and should be performed according to ASTM F710, which directs installers to follow manufacturers’ instructions or, in their absence, ASTM F3191. Some adhesives may be suitable for use on both surfaces but may require different spread rates and open times, significantly affecting evaluation results if applied incorrectly.
- Subfloor and Concrete Conditions Consider the presence of curing compounds and admixtures in the concrete. Curing compounds, which are surface coatings applied to fresh concrete, fall into different categories, such as permanent, self-dissipating, and form release agents, and may need to be addressed before conducting ASTM F3311. Admixtures, added to the concrete mix, can alter its properties and must be considered.
To conduct a successful Mat Bond Evaluation, review the products being evaluated and follow the manufacturer’s specific requirements for acclimation, ambient conditions (including temperature, humidity, and dew point), and substrate surface temperature. Accurate documentation of these parameters, including date, time, location of testing, and details of each flooring system layer being bonded together, is essential. Additionally, document substrate surface preparation requirements and any products installed on the concrete surface, whether removed or remaining. While this evaluation may appear intricate, comprehensive documentation ensures a precise and viable ASTM F3311 evaluation with reliable results.
Attribution: This content is based on information from ProInstaller Magazine.