Mike Little CSI, CDT, CCSMTT, LEED AP is a 50 year veteran of the tile industry. He has spent the last 19 years as a Commercial Architectural Representative for Custom Building Products.
During a recent NTCA online webinar, Little presented a module from the AIA Continuing Education System Program. This program explored the selection process to choose the proper products and installation methods for exterior tile installations, and challenges that may occur. A key point was the importance of early collaboration between tile installers and designers or architects to ensure proper adherence to various codes and standards involved in an exterior project. “The sooner that those two parties can get together, the better and more successful that installation is going to be,” he said.
Little pointed out the importance of the installation standards in the Tile Council of North America Handbook for Ceramic, Glass and Stone Tile Installation, product standards in ANSI A137 and specifications for exterior installation of dimensional stone as per the National Stone Institute. He illustrated the importance of following ANSI A118.10 standards for waterproofing membranes, A118.15 standards for mortars and A118.7 standards for grout to be used on exteriors, and sealants that meet all the requirements of EJ171 in the TCNA Handbook. When considering materials to be installed outdoors, Little advised asking these questions:
- Will the surface material stand up to the thermal rigors of the freeze-thaw cycle, even the backing?
- Is the setting materials compatible with the surface materials?
- If it’s a walk surface, does the tile selected have a suitable slip resistance or dynamic coefficient of friction?
- Is the size appropriate to an exterior application, according to the local codes? This is crucial especially for vertical installation and addresses the size/dimension, thickness and weight, depending if the material is stone, porcelain slab, or other materials.
Little said it’s critical for specifiers to determine appropriate material for specific project conditions — especially for walk surfaces – including type of use, traffic, expected contaminants, expected maintenance, expected wear and manufacturer guidelines and recommendations. He talked about the recently-revised ANSI A326.3 standard for hard surface materials for determining dynamic coefficient of friction (DCOF), and when it’s important for specifiers to obtain manufacturer declared assurance of products for specific DCOF categories.
The design professional also needs to be aware of the IAPMO provisions in the swimming pool, spa and hot tub codes which relate to the minimum wet DCOF of 0.42 for decks, ramps, coping and similar surfaces, and the maximum slope allowed according to American Disability Act requirements.
Little also discussed various installation methods for exterior floors with bonded mortar beds, plus roof decks and balconies and attendant water management strategies, including proper applications of flashings and sealants.
Exterior walls
Little moved to an exploration of exterior wall installations and some of the methodologies that can be employed, emphasizing the importance of achieving flatness in the substrate, particularly for large format tiles.He outlined two primary methods:
- Mortar Bed Installation (W201) , suitable for masonry or concrete bases especially when there are flatness concerns. The mortar bed is typically 3/4” to 1-½” thick and includes a cleavage membrane to accommodate movement and prevent damage. This method allows for a custom substrate.
- Thin-set Application (W202) is for adhering tiles directly to an exterior wall, which often requires remediation to achieve the necessary flatness. The use of a waterproofing membrane is strongly advised to prevent moisture intrusion.
When installing on exterior stud walls, Little stressed the need for proper cement backer boards in compliance with ANSI standards. Movement joints, waterproofing membranes, and appropriate flashing need to be integrated for long-term performance, particularly in areas exposed to water, like pools and fountains.
The right materials are crucial. ANSI 118.15 mortars offer flexibility, and high-performance ANSI 118.7 cement grouts with calcium aluminum binders and higher polymer contents limit efflorescence. It’s also critical to effectively manage water drainage in exterior applications to prevent freeze-thaw damage and efflorescence. Thought should be given to patterns that can facilitate water drainage, like linear patterns. And the importance of practicing EJ171 movement joint methods as illustrated in the TCNA Handbook cannot be overstated.
Little noted the interplay of all these technical and aesthetic considerations in exterior installations underscore the necessity of communication between architects, designers, and installers to ensure overall installation success. Viewers always have the opportunity to ask questions of the presenter in NTCA Webinars, and this one was no exception. Little fielded questions about DCOF, ADA requirements, measuring facial dimensions of tile, installing movement joints with large panels, drainage systems, latex leaching and more.
NTCA maintains a webinar library on the NTCA YouTube channel. Check it out learn more about a wide range of tile-centric topics, both technical and business-oriented.
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Elena Grant
Elena Grant is the Assistant Executive Director of Marketing, Communications and Public Relations for the National Tile Contractors Association and Publisher of its publication TileLetter. Grant has over 20 years of experience leading marketing initiatives, programs, and operational enhancement strategies. As Publisher of TileLetter, she oversees all print and digital communications for the publication.
