The word “organic” provides a clue as to the source of mastic adhesive. It is in fact derived from organic or living material, namely the mastic tree which grows in the Mediterranean, and made into an organic glue. Because of its adhesion nature, it is used as an adhesive.
Mastic adhesive is premixed in a solvent or latex base. This being so, it can be directly applied without being remixed. Mastic is generally applied in areas where moisture will not be an issue, such as kitchen wall tile.
Mastic are only suitable for ceramic tiles because other types, such as marble, are porous, meaning they absorb water. This is a problem because mastic adhesive will re-liquefy when submerged in water and lose its sticking power. Moreover, over time, with porous tiles, the mastic adhesive could seep into the tile and cause the tile to discolour.
However, mastic adhesive is often used on walls in homes because it creates an extremely tight bond with the wall. It also sets quickly, which is an advantage when working with vertical designs because you will not need to stand and hold the tile for as long while it dries.
Mastic as a tile adhesive has a number of weaknesses. For example, since it’s organic, it can become a mold stronghold in high-moisture areas. Also, it does not hold up well against prolonged exposure to water. Therefore even the smallest crack in tile or grout can lead to infiltration of water, which can work its way around or through to the back of the tile, lead to mildew and mold, and eventual cause the surface to deteriorite.
Another point for consideration is that mastic does not provide much structural support and cannot be used to build up minor “off of level” imperfections in a floor.
All that being said though, there are advantages. Mastic has superior holding strength, is easy to apply, and sets quickly. When used to tile walls, its strength allows you to set tile, and if you have a good eye, you can set tile without the use of spacers.
TFO Tile Factory Outlet has some great prices on quality tile adhesives. Visit their showroom or compare prices on their online store.