All About That Grout

August 22, 2018

Posted by D. A. Burns

All About That Grout

We get a lot of questions about tile and stone cleaning, and we find that many questions are related to issues with grout. Although we say we’re tile and stone cleaners, we’re grout cleaners as well.

Most tile cleaning is fairly simple; porcelain and ceramic tiles have hard surfaces that are resistant to damage from any kind of cleaning product. However, potential damage to grout and stone can occur from using the wrong product or techniques.

For example, soap residue, body oils and mineral deposits can be most readily removed using an acidic cleaner. Many do-it-yourself websites recommend using vinegar (acetic acid) as a “safe and natural” solution for cleaning, and many store-bought products contain an acidic component.

Do not fall for this advice! Softer stones like marble and travertine are etched by acids, and the most commonly used grout is damaged by repeated applications of acids. 

Grout Types

There are two kinds of grout used for most tile or stone installations: epoxy grout and cementious (cement) grout. 


If you poke your grout with a knife point and it has a little give, it is likely epoxy. Hooray! You have the rare, easy-to-care-for grout.  As long as your tile or stone is not sensitive to acid, you can use just about any kind of tile cleaner you'd like on it without risking permanant damage.

Epoxies are not absorbent; when modified with Teflon, they are nearly stain-proof. Epoxies are very strong, flexible, and will adhere well, so cracks and loose grout problems are rare. Epoxies also maintain a consistent color as they age.

Sounds perfect, right? So why is epoxy grout so rarely used?

Many installers do not want to work with it. Epoxy requires much more finesse to install it correctly, it takes longer to cure, and it is much more expensive. The cost of an epoxy installation is, on average, between 5 and 8 times more than installing cement grout.

Cement Grout

Akin to mortar, cement grouts have been used for centuries. Typically, cement hardens with age, so really old grout can achieve an almost rock-like hardness. Some positive traits of cement grout include that they are:

  • Inexpensive
  • Easy to work with
  • Great at hiding variations in tile and in underlying surfaces.

Like concrete, cement based grout is porous; a hard sponge. Cement grout needs to be treated properly with a penetrating sealer to be water and stain resistant. It has a naturally high pH (alkaline) so if acidic cleaners like vinegar are used, the grout will begin to soften.

Although we see issues caused by structural movement or installation mistakes, most grout failures are due to cleaning products.  Poking your grout with a pointy object is a great test to determine its type and health. If the grout surface can be easily removed, it may indicate that a repair is needed.

If the grout is hard, hooray again!  Now you just need to make sure the sealer has not been damaged by strong cleaning agents. Here's how you see if your grout has been damaged:

  • Wet the grout in a few areas and see if it gets darker. This may indicate that the grout has become porous and needs an application of penetrating sealer after cleaning. 
  • Try cleaning a small area and see if discoloration remains. This may indicate the need for an intensive cleaning prior to the sealer.
  • None of the above? You may be able to use a mild cleaning product and a little elbow grease to get your hard surface looking good again. 


Cement grout always needs to be sealed. I like to describe cement as a hard sponge; anything spilled on it will go into and through it. Unsealed grout allows moisture to pass through it and get behind the tile surface. Often, that moisture will collect at the base of a wall and either discolor the lower grout or cause the caulk seal at the bottom of the wall to fail. Peeling caulk or moldy caulk are two signs that moisture may be seeping through the grout.

Improper tile cleaning products can also remove grout sealer or even create a rapid soiling problem. Oil-based products like Pine-Sol or Murphy’s Oil Soap remove one residue but leave another. Look for neutral pH cleaners for everyday maintenance of your hard surfaces.

If you want to tackle heavier build-ups or remedial cleaning on your own, use an alkaline detergent such as Spic and Span or Mr. Clean. These are two great options. For that rare treatment of moldy build-up, chlorine bleach may be necessary. Wear gloves and eye protection, and be prepared to work up a sweat!

Miranda B. from Redmond asked…

“My grout is funky and discolored; does the grout have to be replaced? I’ve seen advertising for colored sealers that claim to eliminate the need for new grout.”

Using “color sealing” is fine if you know it is a temporary cosmetic touch-up and that the grout will eventually need to be repaired properly.  Color sealing is just an application of epoxy paint. If the grout is new, has never been sealed, is not subject to traffic or water, the paint can bond well. That said, this combination of conditions is almost never the case when grout is discolored.

Sealers and soap residues that can’t be completely removed negatively affect how well the paint sticks to grout. Areas that are not in contact with water or traffic bond extremely well and the coating often flakes off in other areas. Cracks in the paint at the edge of a tile are the first indication of color seal failure. Trying to remove the paint completely can be more time consuming and costly than simply doing what should have been done in the first place; re-grouting.

Have a hard-surface cleaning question? Contact us with any questions. If you’re in the greater Seattle or Bellevue area, one of our experts can visit to assess your stone, tile, and grout surfaces, and offer recommended service options.

Thank you to the Tile Council of America for some of the facts used in this article. More information than you probably need to know about tile, stone, grout and installation can be found by visiting their site, Tile Council of North America.

At D. A. Burns, we only want to clean tile, stone, and grout using products and procedures that do no harm. This may take us more time, but beautiful, durable finishes are worth it. We also use penetrating sealers, chosen for their effectiveness before their low cost, and we always intend to make repairs that will last.


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