Lippage is the vertical displacement between two adjacent tiles of a ceramic, glass, or stone installation. When excessive, this can lead to numerous problems, ranging from chipped edges to snagged furnishings and appliances to safety hazards.
When properly applied, tests can yield valuable insight into the installed performance of systems, aid investigators in determining the cause of a failure, or help to determine if a product is performing to its intended level. However, when improperly applied, many tests and standards can produce misleading results, improper conclusions, and lead to unnecessary repairs or remediation efforts. Within this context, the article takes an in-depth look at roofing assemblies, along with glazing, masonry, and air barrier assemblies.
Up until the 2008 edition of American Architectural Manufacturers Association/Window and Door Manufacturers Association/Canadian Standards Association (AAMA/WDMA/CSA) 101/I.S.2/A440, North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS), there were five performances classes of windows with differing requirements for test pressures, allowed leakage rates, and other variables. This sidebar discusses the current four types, and their minimum performance grades.
Laboratory testing of fenestration products to the North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS) verifies the performance of a specimen of the fenestration product itself. How can one be certain the specified performance will be realized after installation? When properly applied, field testing can be a useful way to verify actual installed performance during construction and prior to occupancy of a building. The key is testing in conditions that accurately simulate the real-world environment and ensuring that the appropriate test method is applied to the specific installation.
When there is a tile or stone failure, a contributing factor is often the lack of properly installed movement joints. Just like concrete sidewalks and bridges, tile and stone need to have movement joints to control the anticipated movements within a structure. Tile and stone will expand and contract when it is subjected to heat/cold or moisture/dryness. It is critical for architects to properly specify the design, materials, and layouts of movement joints.
Exterior decks and balconies, and interior showers and bathrooms, have historically been problematic areas for the installation of ceramic, glass, and stone tiles. Typically, problems are due to installer error, not using appropriate materials, or not providing clear enough specifications. In each case, it is the result of not following industry standards.