The ceramic tile industry relies on an important set of publications that help define best practices and tile project specifications. While different organizations and committees write these publications, they all build on specialized terminology unique to the tile industry.
To help ensure the tile terminology we use in all these documents is accurate, clear, concise, and consistent, ANSI A108.T American National Standard Terminology of Tile Assemblies provides a useful reference of industry terminology. You can find it in the ANSI A108-A118-A136.1 American National Specifications for the Installation of Ceramic Tile.
Using the Tile Terminology Standard
While many terms are universal across the construction industry, the ceramic tile sector is specialized enough to have its own vocabulary. For the most part, terms that support the tile industry aren’t unique. However, certain terms have different definitions when used in the tile context compared to other segments of the construction industry.
ANSI A108.T defines nearly 200 terms, and some terms are more technical and specialized than others. Without a standardized set of definitions, terms can be open to various interpretations depending on professional experience and perspective. Confusion and miscommunication can arise as a result. Moreover, we risk the proliferation of using multiple terms for the same thing without a standard.
The tile terminology standard streamlines the use of terms. It provides an accurate set of definitions we can consistently apply to all the industry’s reference documents. This eliminates ambiguity and improves communication between a project’s owner and members of the design and construction teams.
As an introduction, let’s examine the basic terms and definitions describing the work on a tile project.
Key Terms in the Assembly
A floor or wall with tile can be a complex part of any construction project. The visible tile finish is the most prominent element. We can define other parts of the construction beneath the tile, all the way down to the structural members. The assembly components are important to understand because they can affect the quality of the tile installation.
We can divide an assembly into two subassemblies — the backing assembly and the tile assembly:
- The backing assembly is the subassembly behind the tile assembly and comprises the structure and the substrate.
- The tile assembly is the portion of the assembly that gets installed over the backing assembly. The tile assembly may include corrective material, membranes, setting material, and finish material.
Backing Assembly
Together, the structure and the substrate make up the backing assembly of a tiled floor, wall, or ceiling.
Structure
The structure is the portion of the backing assembly that includes fixed framing, supporting, or loadbearing members.
For example, the wood or steel studs in a framed wall are the wall’s structure. The joists or trusses supporting a floor deck are the floor’s structure. These structural elements must meet minimum deflection requirements and other criteria to suitably support the substrate and the tile assembly.
Substrate
The substrate is the uppermost portion of the backing assembly to which the tile assembly is applied.
For example, backer board nailed or screwed to the stud framing is the wall’s substrate. Plywood fastened to the floor structure is the floor’s substrate. Substrates have certain requirements to be suitable for tiling:
- Flatness
- Moisture resistance
- Ability to bond to the tile assembly
In some instances, the structure and the substrate are the same. For example, a cast-in-place concrete slab on grade or elevated slab may serve as the floor structure and the substrate to receive tile because no independent structural members are behind it.
Similarly, a concrete or masonry wall to receive tile, whether in a direct-bond application or over a mud bed, qualifies as the wall’s structure and substrate for the same reason. When the substrate and the structure are the same, that material must meet both sets of requirements to receive tile.
Tile Assembly
Once we’ve constructed the backing assembly, the tile work commences. Tile work is the portion of the work within the tile assembly. It may include the corrective material (if present), membrane (if present), setting material, and finish material.
Corrective Material
A corrective material is any material applied to a nonconforming substrate to bring it up to the desired quality to receive tile.
Examples include a mortar bed, flowable underlayment, or patching material installed on a floor or wall substrate. These bring it to acceptable flatness tolerances. Another example is a coating or primer applied to a substrate to facilitate bonding of the tile. A corrective material may or may not be necessary.
Membrane
A membrane is a general term describing a thin layer of material installed to impart special properties to a tile assembly, such as:
- Water resistance
- Vapor resistance
- Sound control
- Bond separation
- Uncoupling
- Crack isolation
A single membrane may provide one or more of these functions. One or more membranes may or may not be necessary in the tile assembly. ANSI A108.T provides thorough definitions for each of the different membrane types.
Setting Material
A setting material is mortar or adhesive material used to bond tile.
Whether bonding directly to the substrate, bonding to a corrective material such as mortar, or bonding to a membrane, the setting material adheres tile and keeps it permanently in place. Many types of setting materials are available, each formulated for various uses and applications.
Finish Material
The finish material is the exposed portion of the tile assembly.
It includes the tile and any surface treatment that we may apply to it. It also comprises the grout joints and any sealant joints or profile strips. Most end users focus on the quality of the finish because this is the visible part of the installation.
Tile Work and Contracts
Now that we’ve defined the tile assembly’s components, let’s address terms for how the work is put in place.
Tile Work
Tile work is the portion of the work required to install the tile assembly to complete the work product. Again, the tile assembly includes corrective material (if present), membrane (if present), setting material, and finish material.
Tile work is typically the work of the tile contractor.
Tile Contractor
The tile contractor is the project team member responsible for delivering the tile work. In the case of a small business, a tile contractor may be a person who works with the tools as an installer. However, the term “tile installer” typically refers to any tile setter or tile finisher participating in the tile work installation.
The tile contractor is the business entity responsible for the work described in the tile contract documents.
It’s important to note that the tile contractor may have responsibilities extending beyond the tile work. In some cases, the tile contractor may be assigned related work, such as installing a backer board substrate. This is part of the backing assembly and not the tile assembly.
Work assignments by the general contractor, construction manager, or homebuilder vary by project. Therefore, lines of communication should be open for the tile contractor to understand the scope of work and to bid that work accordingly.
Tile Contract Documents
The tile contract documents are the complete set of documents describing the tile contractor’s work. These include the construction drawings, specifications, and contract between the tile contractor and the general contractor or owner.
The Potential of ANSI Tile Terminology
The ANSI A108.T Terminology standard defines many key terms and definitions. We reference them in the complete set of ANSI standards for tile and the TCNA Handbook for Ceramic, Glass and Stone Tile Installation.
It is anticipated that with the use of this tool to streamline communications before and during construction, efficiencies in the installation of tile will increase and potential confusion on a tile project may be avoided.
