The selection of ceramic and natural stones has grown exponentially over the past few decades. The selection of materials, workmanship and size of the tiles is enormous. Regardless of the size, material and properties, tiles are placed so that a narrower or wider gap or joint is left between the tiles.
The grout must fill the gap between adjacent tiles, tolerate some movement or deformation of the tiles, and be extremely resistant to dirt and wear. The tone of the grout must match the tile, either by merging visually into one or by emphasizing the contrast.
Cement-based grouts are the most commonly used, which we produce for joints of different sizes and in a wide range of colours; for surfaces subject to increased mechanical and chemical stress, epoxy-based mira multipox grout is suitable. The mira supersil sanitary silicone is used in the joints between different materials and other types of similar joints.
Before filling the joints, make sure that the tile adhesive has hardened, as moisture that dries out from below can ruin the tone of the grout. The joints must be of similar depth and width, and clean.
The grout must always be mixed with an electric mixer. Manual mixing may not be sufficient. Ready-mixed mortar must stand for a few minutes, to allow the powdered components to melt, after which it is lightly mixed once more, with the grout then being ready for use. The amount of water is also important, excess water introduced into the joint during mixing or washing leaves the joints weak and variegated after drying. The excess water in the grout after drying is also responsible for causing needle-sized holes.
The grout is applied to the joints with a rubber tab, diagonally, with the excess grout being removed from the tiles using similar movements. The joints must be filled to the bottom, which usually requires repeated strong pressing.
If the joints are strong enough that they do not deform when pressed with a finger, it is time to remove excess grout and grout haze. A thin layer of grout on the tiles dries at a much faster rate that the hardening of joints, and starting too early with the washing process will result in the washing out of the still soft surface layer of the joint, with the joints appearing variegated. A well-wrung sponge should be used during washing, excess water can potentially make the joints weak and variegated.
The freshly grouted surface should be protected from dust, etc., for a few more days. Use mira care products when performing maintenance later on.