When most people think of sealing stone tiles, they are mostly thinking of sealing the top surface and nothing else. But as we’ll see, there are times when it’s really beneficial to seal all six sides of the stone; that is to say the front, the back and the 4 vertical sides.
The main reason to apply a sealer to a stone tile is to add a degree of stain resistance to the finished (or visible) surface of that stone. However, there are times when sealing the back and also the sides can help prevent other problems.
Consider a polished stone like a marble. The stone itself is porous to some degree, the polished surface of the stone is actually less porous than the rest of the stone. The reason for this is the polishing process, which creates a high stress surface that is much denser than that of unpolished marble.
Some of these stones are quite susceptible to bleeding: usually the short edges are saw cut and much less dense than the surface, when the tiles are grouted the relatively high porosity at the edges can absorb water from the grout . If the grout is pigmented, then the color may bleed into the marble. The result is an effect we call a picture frame; basically a stain around the edge of the tile. Since this ‘stain’ comes from the edges and the entire depth of the tile joint, it will be very deep into the tile and virtually impossible to remove.
Many people are becoming more aware of the role a sealer can play in protecting a stone’s surface from staining, so it’s a bit strange that so few consider the effect of grouting on a much more porous and complex surface. therefore more “dyeable”. ; the edges. This problem can be significantly reduced or even completely avoided by sealing all sides that come into contact with wet fixing materials, in other words all six sides.
It is perfectly acceptable to use the same sealer for the back and sides that you plan to use for the surface. However, the role of the sealant in the exposed surface finish will be resistance to long-term deformation. While all we’re looking for on the back and sides is a temporary barrier against stains and water, once the adhesive and grout have cured the risk of bleeding isn’t as great anymore; once the grout has cured and the water has evaporated, the problem has been avoided. So we don’t necessarily need the same degree of stain protection and we don’t need a sealer with the same longevity that we would want for the surface. In which case, we may be able to use a much cheaper sealer on the back and sides, reserving the premium (more expensive) one to seal the stone on exposed or visible surfaces.
Be sure to apply the sealer correctly. Pay particular attention to removing excess sealer before it dries to avoid leaving a residue that can break the bond.
