**Everything You Need to Know About Tile and Stone Installation **
Members of the architecture and design community continue to demand high performance from the beautiful ceramic tile and stone installations specified in their projects. Today, professional, specialized contractors are asked to install these finishes in mor e places than the usual "wet areas" generally characterized by commercial kitchens and bathrooms. Tile and stone can be used in virtually any room of any building for functional purposes, or simply for its beauty.

However, due to the increased use of tile and stone in commercial interiors, builders have to adjust the way their structures are designed and built beneath ceramic tile and stone applications.
Traditionally, it’s been taken for granted that the structure could be of the same construct that’s beneath hardwood, resilient or carpeted areas, but with the increasing popularity of large-format tiles and stones – and longer spans for larger rooms – failures can occur if the structures aren’t designed properly. Builders must rely on strong interior design plans for these construction projects. The areas that receive ceramic tile and stone must be designed to a more rigid standard than those which are finished with other materials.
Structural Requirements for Installations

Before any work starts, the surface must be rigid enough to accept the tile or stone. The TCNA Handbook for Ceramic, Glass and Stone Tile Installations, published by the Tile Council of North America, explains that it’s the responsibility of the project architect, designer or engineer to determine if the substrate meets the proper stiffness and deflection criteria.

The substrate needs to meet the maximum allowable deflection for the finish and the installation system that will be installed. Deflection is the potential movement which the installation may experience when subjected to load and use. Ceramic tiles and stones are very rigid and thus will not be able to handle excessive movement in the substrate. All substrates therefore should meet the maximum allowable deflection rating of L/360 for ceramic tile and L/720 for stone applications installed over wood framed constructs. Some adhesive manufacturers will allow an L/480 deflection standard for stone applications.
It’s important to keep in mind that these maximum allowable deflection standards are very different from the L/360 design standard that’s called for in most building codes. The building code requirement applies to a uniformly applied load across the spans, but it’s not uncommon for ceramic tile and stone applications to be exposed to concentrated loads.

A good example is when a person is walking over a structure wearing high heels. This exerts a tremendous concentrated downward force upon a very small area. A person weighing 150 pounds and concentrating her weight load on a small heel is distinctly different than the same 150 pounds being uniformly distributed over the span of an entire floor. Appliances that sit on "legs" or wheels will also concentrate their weight load, as well. Therefore, when ceramic tile and stone floors are exposed to concentrated loads, the engineer and/or specifier must specify an appropriate substrate to accommodate it.
Some other things to note:
• What will the areas that receive the tile and stone be used for?
• How many people will be using that area?
The more people that will use a space, the more rigid the structure must be. A floor that is designed at a 40 pound total live and dead load may be suitable for usage by four or five people. But what if this business space changes and that same floor space is subsequently used regularly by 30 people? What may have been rigid enough for a small group of people may now be pushed beyond its deflection limits, which can cause cracking of grout, or even worse, cracking of tiles and stones.
Substrate Types
Exterior glue plywood, cement backer units and concrete are the most common flooring types for builders. There are also many uncommon types which remodelers frequently come across. These include existing finishes like [ceramic tile and stone](https:agtileandstone.com/) or resilient flooring. They even run into substrates that still have old adhesives on them.Exterior glue plywood, cement backer units and concrete are the most common flooring types for builders. There are also many uncommon types which remodelers frequently come across. These include existing finishes like [ceramic tile and stone](https://agtileandstone.com/) or resilient flooring. They even run into substrates that still have old adhesives on them.
Tile and stone are able to be successfully installed over certain types of uncommon finishes, provided that proper precautions are taken.
Proper Preparation
With all tile and stone installations, proper surface preparation is perhaps the most important phase of the work. Even when it needs to be specifically addressed, not enough time or resources are generally allocated to ensure that this is done correctly. This scenario is especially true in renovation work. (One never knows what one may run into when starting to renovate a commercial interior.)
All substrates must be free of any bond-breaking or bond-inhibiting materials. These may include sealers, waxes, curing compounds, form release agents, paint, dirt, grease, oils, old carpet adhesives or other contaminants. They must be completely removed prior to the tile or stone installation.
One of the best ways to remove these contaminants is via the mechanical abrasion method. Usually, the contaminants have penetrated into the substrate's pores and will block an adhesive's ability to create a mechanical bond or attachment to the surface. It’s not good to use chemicals or acid to strip/remove these contaminants. Chemicals or acids may penetrate into the substrate and will become virtually impossible to remove.
Cracks
If you find existing hairline cracks on a concrete substrate, use an anti-fracture membrane to help reduce the transmission of the cracks to the tile or stone.