Many homeowners choose tile as a surfacing option for their kitchen or bathroom. Tile has many advantages. It can be very durable, easy to install and inexpensive, depending on what kind the homeowner wants to use. Typically, tiles like ceramic versions are used with a wider grout line, while stone tiles are used with a very slim grout line. No matter what type of grout is used, sealing the grout lines is a very common installation step.

Grout is sealed to protect from water damage.


Grout is simple a putty used to fill in the spaces left between tiles. This keeps the tiles from rubbing against each other and cracking, while making sure that water or other liquids cannot leak down between any types of tile. There are two main types of grout, sanded and unsanded. Sanded grouts are mixed with sand and used most often with ceramic tiles. Unsanded grouts are used more often with stone tiles. Both types can be sealed.

Sealed Grout

Sealed grout has a chemical sealant applied to its surface. This sealant covers only the grout and then cures to make a protective shell that keeps liquid from being absorbed into the grout and staining it or the nearby tile. Some sealants soak into the grout before curing, while others only rest on top.

Unsealed Grout

Unsealed grout tends to be more absorbent than sealed versions. This is why most installers recommend that grout lines be sealed after application. Unsealed grout often leaves the cracks between tiles open to stains and, in bathrooms, mold problems. The qualities of the grout itself are largely unchanged.

Effect on Grout

Sealants are designed to be clear and nonintrusive, changing neither the grout nor the color of the surrounding tile. However, most sealants do make lighter grouts somewhat darker in shade. The effect is not usually noticeable in the thin, dark grout lines used with stone, but with white or off-white grouts a noticeable darkening often occurs, making it darker than unsealed versions.

Types of Grout

Sealing can also depend on the type of grout used. Most grout is designed to be sealed. Some grouts, however, are made of epoxy substances and do not need to be sealed. This type of grout works better unsealed, and sealing may cause peeling problems later in the life of the grout.


Grout does not come sealed. This means that not sealing grout lines will save the money it could cost to purchase and apply a sealant. This cost does not usually reach beyond $50 to $100 for an application of sealant.