While finishers make up a significant portion of the WOC seminar audience each year, engineers, concrete material suppliers, concrete construction managers, and other related personnel also attend. Recently, ACI Committee C640 has focused on facilitating certification for individuals who have work experience but were previously hindered in seeking certification due to language barriers or educational challenges not associated with their knowledge and skills in concrete finishing.
Concrete flatwork finishing certification is offered in the following categories:
- concrete flatwork associate, finisher, and advanced finisher;
- decorative concrete flatwork finisher and associate; and
- specialty commercial/industrial flatwork finisher and technician.
Associate, finisher, and advanced finisher designations used within the three ACI finisher programs differ not only in the knowledge required to gain certification, but also in the level of hands-on skill required. The three finisher programs represent types of finished flatwork installation. Concrete flatwork certification focuses on proper procedures and equipment to place, consolidate, finish, edge, joint, cure, and protect concrete flatwork. Decorative concrete flatwork certification focuses on placing, finishing, curing, and protecting decorative concrete flatwork. Specialty commercial/industrial flatwork certification addresses additional areas of concern and has several riders, or add-ons, available. The high tolerance floor construction rider requires an applicant to know how to manipulate fresh concrete to achieve floor tolerances that meet predefined numerical levelness and flatness measurements. The surface treatments rider includes information on items such as applying and embedding aggregate hardeners. The silica fume rider requires applicants to place, finish, control evaporation, and cure silica fume (also called micro-silica) concrete. Those who wish to obtain their ACI certification as a specialty commercial/industrial flatwork finisher and technician must take a written examination and complete a performance examination, constructing an actual superflat slab using a vibratory truss screed and/or riding trowels, straight edges, check rods, channel floats, finish blades, and various hand tools. For full definitions of certification categories, see “ACI Committee C640 Concrete Flatwork Definitions.”
Adoption of the flatwork certification programs
Soon after the certification’s initial offering, specifiers for big-box stores and other commercial/industrial facilities began to require flatwork crews have at least one ACI-certified commercial/industrial finisher. In the more than 10 years since, requirements for certified personnel have grown significantly. For example, the largest online retailer, who previously required the use of ACI flatwork finishers, has added a requirement for ACI commercial/industrial flatwork finishers on every project. Considering they have more buildings currently under construction than any other private entity—approaching 100 in the United States alone—this represents a great increase in demand for ACI-certified flatwork specialists. In many of these facilities there are thousands of robots, whose efficient operation depends on extremely high-quality concrete floors with respect to flat and level floor tolerances as well as minimal cracking and defects. Shutting a facility down for floor repairs is unacceptable.
Another extremely large retailer has plans to build approximately 60 distribution facilities in the United States. They have stated their intention to specify ACI-certified advanced finisher personnel (in addition to ACI-certified flatwork finishers, who have been required for more than 15 years) for construction of both distribution facilities and stores. Yet another big retailer has specified ACI-certified flatwork finishers for a similar period of time and also expects to soon require advanced flatwork finishers and commercial/industrial finishers.
Many retailers are now building stores with polished concrete surfaces. These floors are aesthetically pleasing, have lower first and maintenance costs, and a lower potential liability for slips and falls. However, retailers have learned that if the floors are not flat enough, the polished surface makes imperfections such as humps and dips very noticeable. Thus, they are specifying higher F-numbers and ACI-certified flatwork finishers and commercial/industrial finishers to ensure the floors meet or exceed the owner’s expectations.
Across all industries, assessment and certification credentials demonstrate competence and skill. Concrete construction work should not be an exception. The construction industry should not only expect quality work, but also specify craftspersons that have proven their knowledge and experience by becoming ACI-certified. Specifying these tradespersons ensures concrete installations reflect the expectations of the owner, requirements of the general contractor, and intent of the specifier.
John W. Nehasil, FACI, is the managing director of certification for the American Concrete Institute (ACI). He has been employed by ACI for more than 40 years, including over 14 years of editorial and publishing experience and 29 years of experience in certification program administration. Nehasil is an ACI Fellow, graduate of the U.S. Chamber of Commerce’s Institute for Organizational Management, and a member of the American Society of Association Executives (ASAE).
Bryan M. Birdwell is a senior floor and paving consultant and a principal with Structural Services Inc. He was an owner of a concrete construction company for many years that had a wide range of projects including commercial and industrial high tolerance slabs-on-ground, suspended slabs, parking lots, and pavements.
Jerry A. Holland, PE, FACI, is vice-president and director of design services for Structural Services Inc. He has over 50 years of worldwide experience in the design, construction, and troubleshooting of concrete materials, floors, pavements, structures, and geotechnical problems. Holland is a long-term member of all of the American Concrete Institute (ACI) committees that deal with the design and construction of concrete floors and paving.
