Grout is a construction material used to embed rebars in masonry walls, connect sections of pre-cast concrete, fill voids, and seal joints (like those between tiles). Grout is generally composed of a mixture of water, cement, sand and sometimes fine gravel (if it is being used to fill the cores of cement blocks). Sometimes color tint is applied as a thick liquid and hardens over time, much like mortar.

It is also a component of mosaics. Although ungrouted mosaics do exist, most have grout between the tesserae.

Main varieties include: tiling grout (either cement-based or epoxy), flooring grout, resin grout, non-shrink grout and thixotropic grout.

There are a few tools associated with applying and removal of grout such as:

• grout saw or grout scraper; a manual tool for removal of old and discolored grout. The blade is usually composed of tungsten carbide.
• grout float; A blade-like tool for smoothing the surface of a grout line
• grout sealer is a water-based sealant applied over dried grout that resists water, oil and acid-based contaminants.
• Dremel grout attachment; an attachment guide placed over a Dremel rotary tool for faster removal of old grout than a standard grout saw.

See also

• Mortar
• Mortar joint

Until about 40 years ago tile was grouted with traditional portland cement based tile grout or mortar. Cement based grouts can be colored using integral colors or dyes to a wide variety of colors. Cement grout, however, has limitations in that it can become brittle allowing it to crack, weakening the tiled surface. It also requires maintenance in the form of a sealer which must be applied up to 4 times per year. Customers were looking for more. Water-proofing issues, along with inconsistent color and strength were the most common problems. Then came epoxy-based grouts which are water-proof and offer superior strength and color-fastness, but are hard to work with and become brittle over time as well. The epoxy-based grouts also suffer from extreme UV sensitivity causing them to fade when exposed to direct sunlight. The highly allergenic properties of epoxy created yet another problem for installers and their customers as many refused to work with it, or simply raised their installation fees beyond the budgets of their customers. The newest generation of grout is the urethane based Quartz-Lock grout system. This combination of high-grade urethane and color-fast quartz silica creates a water-proof, semi-elastic, high strength, grout that is easy to use, and out performs its predecessors in nearly every measurable aspect.

External links

• Applying grout to floor tiles
• Sealing tile grout