Traditionally provided by an architect, a tile installation spec can also be written by anyone designated by the Construction Specification Institute (CSI, www.csinet.org) to do so. But in spite of the fact that it takes a considerable depth of knowledge, tile installation specifications are written all the time by people with no qualifications at all.
Unfortunately, much of this work fails because the specs-and resulting installation-are inadequate. If you are a tile installation contractor who is not working under a decent specification program, and do not have the time to enroll in CSI classes, you need to have a reasonable grasp of the ANSI Standard Specifications for the Installation of Tile (ANSI A108), and the Handbook for Ceramic Tile Installation, both of which are published by the Tile Council of America (TCA, www.tileusa.com), and are the foundation for CSI and other tile installation-related programs.
Architects and installers often refer to the methods found in the TCA Handbook as TCA Standards, when, in fact, the TCA Methods merely describe, in a user-friendly way, the most common tile installations and the most appropriate ANSI A108 specifications to reference. Flooring contractors will be particularly interested in page 12 of the most current TCA Handbook-the 2003-2004 or the 41st edition-where a floor tile installation guide can be found. This helpful guide can be the foundation of your specification program because it routes you to the most appropriate methods for a variety of uses ranging from residential to extra-heavy duty.
A closer examination of a particular TCA Method-F122-03, for example-reveals an ANSI spec for a waterproofing membrane, for the membrane installation, for the latex-portland cement thinset mortar, for the polymer-modified tile grout, and for the tile. In addition, it instructs the architect (or designated designer) to specify the type of movement joints required, as well as location and frequency, as specified in EJ171.
EJ171 is an example of a desirable spec that is a part of the ANSI A108 specifications, but whose function and importance is not immediately underscored by a definite link between the TCA Method (EJ171), and the appropriate ANSI a108 spec: ANSI AN - 3.7. In my opinion, EJ171 is more useful and specific compared to ANSI AN 3.7.2, 3.7.3, and 220.127.116.11, but the spec that finds its way into a bid proposal can also be an arbitrary number based on actual spacing of the construction components.
By invoking a specific ANSI number, or a TCA Method reference, a specification can include and impose technical tolerances on all the tile and materials used for a particular installation, but a good spec includes more than just technical data. A decent spec must also address surface preparation issues: how flat, how sloped, how level. If the setting bed surface is not going to be provided by the tile installer--a concrete slab or a plywood subfloor, for example-a tolerance of 1/4-inch in 10 feet needs to be imposed for tiles 10 inches or less.
Deflection is a major issue with ceramic tile, and grows more critical with some stone tiles, and as tiles (ceramic or otherwise) increase above 10 inches. A maximum, uniform deflection of 1/360th of the span is allowed for ceramic tiles under 10 inches: this amounts to approximately 1 inch for a 30-foot span, or about 3/64ths-inch between joists spaced at 16-inch (maximum) centers. Engineered flooring systems with joists spaced greater than 16 inches claim to meet uniform deflection of 1/360, but tiles require the standard be applied to uniform and concentrated deflection (the deflection measured between neighboring joists). A good spec demands that this value be met, with an extra-cost fix.
A reasonable surface preparation spec can also factor in the cost of repair of structural damage should it be discovered during the demolition and discovery phase of a remodeling project. This can include: the replacement of subflooring, the replacement or addition of vertical or horizontal blocking, the replacement or addition of framing members, the addition of crack isolation, waterproofing, or sound attenuation systems, and the repair, replacement, or addition of structural members. In rather plain language, a reasonable spec can spell out what you intend to charge if additional work is required, and the compensation for work completed should the owner decide to finish with another material.
A reasonable spec can-and should-include provisions for allowing materials enough time to cure. If the installation has to return to service quickly, rapid-setting material, only, should be specified. In all cases, or wherever practical and reasonable, installation materials should be single-sourced from a manufacturer willing to write a specification to meet your particular needs. This may be the easiest and most efficient way to have a spec written provided all the materials are available locally. Otherwise, your spec should, at the very least:
1. Describe the scope and size of the installation.
2. Identify the tiles and materials to be used for the installation.
3. Identify the type of installation (through a TCA Method, if possible).
4. Identify the work and tolerances required of other trades.
5. Affix a price for any repair work needed to complete the installation.
6. Include a scheduling allowance should repair work delay the installation.
7. Provide for adequate protection for the installation once work has been completed.
8. Alert the consumer to the conditions of any warrantees included with the installation.
9. Assert a reasonable payment schedule and a means to mediate disputes.
With these minimum factors at play, your client can make realistic quality comparisons, you can be assured of delivering a quality product, and profitability for all the work you perform.