Spot Bonding

Spot bonding is an improper adhesive mortar application technique where an installer uses a few dabs mortar to bond tile and stone.

Spot bonding typically involves four or five dabs of cementitious adhesive mortar that is placed on a tiles backside before it is installed. The tile is then pushed into place onto the substrate which flattens the dabs in pancake shapes- as shown in the picture. Industry standard methods and manufacturer’s written installation instructions clearly state the correct mortar application techniques and subsequent coverage that must be met for certain installations.
 
Several ANSI standards including ANSI A108.5 state that, “Average contact area shall not be less than 80% except on exterior or shower installations where contact area shall be 95% when no less than three tiles or tile assemblies are removed for inspection.” Standards for setting certain tiles in certain applications call for using techniques and proper sized trowels to meet the specified contact percentage. Two often used and very successful methods from some tiles and applications are back troweling and single direction troweling of adhesive mortar.
 
Spot bonding is a serious problem that our industry must overcome to assure installations perform as intended. There is an ongoing effort to combat this technique through education and awareness but still more needs to be done. Many average installers simply do not know and or do not care about standards and deploy the spot bonding method to save installation time and material cost. Unfortunately, this leaves the project owners left with a bad job potentially ready to fail at any time.
 
We offer quality control services that can be tailored to any budget where we deploy our expert seasoned installers to the site to oversee and assure a project is not installed with spot bonding and see that it is performed correctly and that it will perform for the intended lifetime. Qualified installers are in high demand and are often very difficult or expensive to hire. Using one of our installers to oversee your contractor or installers may be the difference between project success or a spot bonding failure.