Tile mastic is a type of adhesive used for securing tiles to walls, floors, and countertops. While traditional thin-set mortar is made from primarily organic materials, mastic is made using synthetic polymer compounds. Tile mastic is considered an easy-to-use alternative to mortar, but may be more difficult to work with than peel-and-stick tile products. This material is frequently used when installing new tiles during kitchen or bathroom renovation projects.
This material is typically used with relatively small ceramic or porcelain tiles, but rarely used with stone tiles like granite or mortar. This is because these materials are relatively porous, and may soak up the moisture in the mastic, causing it to fail. Tile mastic is not generally recommended for floors because it is too soft to support foot traffic.
Mastic should only be used in applications where the subfloor is relatively dry and sealed. When tile mastic is used, the tiles must be grouted and sealed to prevent water from seeping through the joints. In bathrooms and other wet areas, mortar is generally used in place of tile mastic.
To use this material, apply it across the installation surface using a notched trowel. The lines in the mastic bed should run across the wall horizontally to help support tiles against the force of gravity while the mastic dries. It may be necessary to add framing or supports when installing heavier tiles, as the mastic may not be sufficient for supporting the weight of the tiles until the adhesive dries.
Tile mastic offers many benefits to users. It is easy to work with, and is generally pre-mixed, unlike mortar. Novice users may find it difficult to mix mortar in the right proportions for effective use, which may cause cracks and maintenance issues over time. Mastic is also very effective for holding small tiles in place on vertical surfaces like bathroom walls and kitchen backsplashes.
In addition to these benefits, there are also a number of potential drawbacks that should be considered when using mastic. While mortar can be used to even out a non-level surface slightly during installation, mastic is not thick enough for this type of use. If tile mastic is used to bring low areas up to the same level as higher ones, the tiles are likely to suffer cracks and other signs of damage over time. Mastic is also not recommended for outdoor use, as it is generally unable to withstand temperature changes and moisture from rain or snow.