Placement of movement joints in the tile assembly is described in ANSI and the TCNA Handbook. They should be placed every 6 to 7.6 m (20 to 25 ft) in interior spaces and every 2.4 to 3.6 m (8 to 12 ft) in exterior installations and areas exposed to direct sunlight. Soft joints should also be installed wherever there is a change of plane or independent movement of two surfaces is suspected. With some of the large-format tiles, up to 1.5 x 3 m (5 x 10 ft), it is best to fill all the joints around the tile with the elastomeric sealant to meet the industry recommendations. Caulk and sealant are formulated in nearly every colour to match the hard cement and epoxy grouts available.
Conclusion
Selecting the right grout may seem daunting with so many choices, but proper selection will ensure the tile assembly’s longevity. In the past, cost was a major consideration in product selection and using a specialty grout that was several times more expensive was out of the question. Now, an increasing amount of large-format tiles are specified, and the amount of grout required for the job has been significantly reduced.
For instance, to tile 93 m2 (1000 sf) with 203 x 203 mm (8 x 8 in.) tile and a 6.35-mm (¼-in.) joint spacing requires about 90 kg (200 lb) of cement grout. If the tile size is increased to 609 x 609 mm (24 x 24 in.), the project only needs 34 kg (75 lb) to fill the joints in 93 m2 (1000 sf). With the market trend toward larger tiles, the cost of the grout becomes less important. This makes it easier to justify an appropriate grout that provides uniform appearance, consistent colour, crack resistance, and stain-proofing at a higher price.
When specifying tile on a project, one should go beyond colour and analyze how the installation is going to be used. Designers and project teams want the artistic quality of the installation to be visible for years to come, so it is important to select materials that stand the test of time. For demanding installations, a high-performance epoxy grout or one of the newer premixed or ready-to-use grouts should be considered, rather than a lower-cost traditional grout.
The same grout should not be repeated out of convenience, unless this installation is identical to the last. Every installation has its own unique needs and deserves a full evaluation. Many grout manufacturers have professionals on staff that understand the different grout types and can help with the best selection for any tile project.
Steve Taylor is director of architecture and technical marketing for Custom Building Products. With more than 30 years of experience developing products for the construction industry, he is on the board of the Tile Council of North America (TCNA), a member of Material and Methods Standards Association (MMSA), and American National Standards Institute (ANSI). In these roles, Taylor helps to determine proper tile installation methods and product standards. He can be contacted at stevet@cbpmail.net.
