Have you looked at the photos in this article and noticed a real problem? They all demonstrate low grout joints which do not meet the tile industry standards. To meet these standards, the grout must adequately fill the space which obviously these examples do not.
And yet, when the person who took these photos shared them with his builder on the job site, the builder did not believe that any standards existed or that there were any organizations that develop them.
Have you found yourself in a similar situation?
If yes, here's how to deal with low grout joints and understand tile installation standards.
Selecting the right grout for your tile installation
Before addressing low grout joints, let's briefly explore the types of grout available. In both the TCNA Handbook and the NTCA Reference Manual, you'll find the Grout Selection Guide which details the different products and considerations based on the type of tile selected and the exposure in which it will exist.
- Sand-Portland Cement Grout (made on the job using sand and cement)
- Standard Cement Grout (unsanded and sanded)
- High Performance Tile Grout (unsanded and sanded)
- Grout Color Selection
- Stain Resistance and Color Consistency of Cementitious Grouts
- Epoxy Grout (100% solids)
- Epoxy Emulsion Grout
- Furan Resin Grout
- Premixed Polymer Resin Grout
As the TCNA Handbook Grout Selection Guide explains,
"Portland cement is the base for most grouts and is modified to provide specific qualities such as whiteness, mildew resistance, uniformity, hardness, flexibility, and water retentivity. Non-cement-based grouts such as epoxies, furans and premixed polymer resin grouts offer properties not possible with cement grout. However, special skills and precautions on the part of the tile setter may be required."
Be sure to read through the guide so you select the right grout for the job.
Dealing with low grout joints
In this particular situation, although the type of grout selected for the project may not have been the best, we're focusing primarily on the unacceptable installation practices seen here.
ANSI A108.10: the Standard for Installation of Grout in Tilework
The ANSI (American National Standards Institute) Standards for the Installation of Grout in Tilework provide critical guidance for how grout is to be applied and finished.
A valuable overview is provided in ANSI A108.02, General Requirements for Materials, Environmental, and Workmanship. This section covers the components used in tile assemblies as well as determining the size of grout joints.
In terms of the proper fullness of grout joints, ANSI A108.10 is the standard for Installation of Grout in Tilework. A108.10 section 5.3.4 requires that,
“All grout joints shall be uniformly finished. Cushion edge tile shall be finished evenly to the depth of the cushion.”
Check the NTCA Reference Manual chapter on Grout
The National Tile Contractors Association (NTCA) publishes the highly regarded NTCA Reference Manual that covers nearly every aspect of tile installation in a problem, cause, solution format. It can and should be used by all tile contractors to understand potential issues with tile installations and how to avoid or recover from problems.
Chapter 8 of the 2017/2018 NTCA Reference Manual talks about Grout. Page 211 includes a discussion about the Problem, Prevention and Cure associated with Low Grout Joints.
"Low Grout Joints" are defined as not being up to the top edge of the tile or cushioned edge, depending on the profile. Some of the problems leading to low grout joints include,
- Joints that aren't filled properly during application
- Using too much water and washing the grout out of the joints
- Using a soft float or sponge during the grouting process
- Joints settling as a result of voids under the edges of the tile
- Improper selection of grout for the specified use, and size of the joint
- Strong acid cleaning or using acid too early after grouting
The NTCA Reference Manual addresses each of these problems with prevention and cure recommendations.
The chapter on Grout also covers issues such as pinholes, powdery or soft joints, rough textured joints, inconsistent color, crazing and/or cracking, and efflorescence.
Who sets Tile Industry installation standards?
As we've previously discussed in this blog, the Tile Industry works closely together to ensure, given the rapid pace of change in products and materials, that installation standards deliver the best possible performance.
To that end, representatives from all facets of the industry participate in the development and writing of standards including representatives from the NTCA, the world’s largest association of tile contractors. They are members of the committees that write the standards, methods and details which are recognized, highly regarded and utilized by the tile industry.
The industry's installation standards are found in the Tile Council of North America (TCNA) Handbook and the American National Standard Specifications for the Installation of Ceramic Tile (ANSI A108, 118, 136.1, 137.1, 137.2).
Be sure to review the TCNA FAQs on Grout and Grout Joint Size.
Want to become involved in tile installation standards development?
If you'd like to become involved in supporting the Tile Industry, here are a few steps to consider.
- Membership in the NTCA is a valuable resource for all professional tile contractors or any contractor who installs tile. The primary mission of the NTCA is training based on these tile industry standards and it is committed to improving the installations and performance of contractors throughout the United States. Every installer should own and be familiar with the standards, methods and details that guide the tile industry.
- Become a CTEF Certified Tile Installer (CTI). The Ceramic Tile Education Foundation (CTEF) provides education and training for tile setters and encourages them to become certified. The CTI program is a highly sought after certification for tile installers who wish to achieve a higher level of professionalism and recognition in the tile industry. As a CTI, you set yourself apart from the crowd and know how to anticipate tile installation problems before they occur. Do it right the first time and get paid accordingly.
Are you now better equipped to address low grout joints?
Have you seen this problem in the field? How did you respond? Do you feel better prepared to address low grout joints the next time you encounter them?
Please send your comments.
Thanks for reading.