Tuesday, July 8, 2014

Identify Cement Tile Grout Haze and Remove It


One of the greatest joys about blogging and my love of tile is sharing fabulous installations using cement tile like this one featured in House and Home. The cement tile installation uses a Geometric Moroccan Circle pattern in soothing green.

Cement Tile in a Geometric Moroccan circle pattern. Image credit: House and Home
Cement Tile in a Geometric Moroccan circle pattern.
Image via House and Home
I also enjoy educating people about cement tile and making sure they know the differences between cement tile and it more ubiquitous cousin, ceramic tile. Because it is very porous, cement tile is more prone to grout haze than glazed ceramic tile. Today, I'll explain why grout haze occurs, how you can spot it and how to remove it.

Spotting Grout Haze

Last week I received an email from one of the design firms in Berkley, CA, that we work with. Overall, the design firm's client was thrilled with the tiles and the install. The installation featured our Geometric Moroccan Circle cement tile for a bathroom in San Francisco. The tiles were installed on both the floor and wall. Unfortunately, a "white film on the tile" could be discerned after they were sealed.
Grout Haze on a Cement Tile
Grout haze on a cement tile installation.

The "white film" you see on the dark green pattern of the tile is grout haze. Grout haze will generally appear as a white or grey streak on the dark colors in the pattern. The streaking color will depend on the color of grout you choose. 

Streaking caused by residual grout left on cement tile.
Streaking caused by residual grout left on cement tile.

Understanding Why Grout Haze Occurs

During the installation, the tile is smeared with grout. The streaking occurs from the float or squeegee that is raked over the tile.

Remove grout with a rubber float and sponge right after grouting to avoid grout haze
Always remove grout with a rubber float and sponge.

The installer has to physically remove as much grout as possible with a rubber float and then with a sponge after coating the tile with grout.

A very liquid grout must be used for cement tile to avoid grout haze.
A very liquid grout must be used for cement tile to avoid grout haze.

If the grout becomes too dry during application, it can penetrate the cement tile pores. The haze will become apparent after the water on the tile surface evaporates and leaves behind the minerals from the grout. Remember, the grout is applied between the spaces of tile using a tile float, and then wiped away with the same tile float and a wet sponge. Follow these best practices when grouting.

Best Practices for Grouting Cement Tile

  1. You may use colored or white grout. If you decide to use colored grout, then we recommend that it be a color that is the same, or lighter than, the lightest color used in the pattern.
  2. The grout should be fluid enough to completely fill the joints.
  3. Apply the grout with a rubber float or with a rubber squeegee, always moving diagonally across the joints.
  4. Any excess grout should be removed with a damp cloth or sponge before it dries.

How to Remove Grout Haze on Cement Tiles

Follow or share these tips with your installer to avoid, minimize and remove grout haze. These guidelines apply only to cement tile installations.
  1. Make sure to physically remove as much grout as possible with a rubber float and then with a sponge.
  2. Make sure the tile is completely dry, clean and free of grout before applying a penetrating sealer.
  3. Start with a light buff and clean. For floor installations, buff the floor with a floor polisher and white pad. Use just a bit of water and change the pads frequently to encourage the clean-up of any grout.
  4. If you don't achieve the results you are looking for, then attempt a deep cleaning. A deep cleaning is achieved by buffing the floor with a floor polisher and green pad using a lot of water and pH neutral soap. This must be done prior to applying a penetrating sealer. The goal is to really clean the floor of any dust, grout, pigments or debris prior to sealing. The use of a floor polisher and green pad isn't usually necessary on polished tiles. Polished cement tiles are "buffed" at the factory to achieve a satin sheen that simulates the look the tiles acquire after years of normal use and care. The surface of a polished tile is smooth compared to an unpolished or raw cement tile. The smooth surface of a polished tile makes it easier to install because grout is less likely to penetrate the tiles.
  5. In locally severe locations or if the tile has been sealed, use 800 grit wet sandpaper and water to remove excess grout.
Cement tile is fairly easy to clean with a floor buffer or rags, water, soap and elbow grease. Occasionally, fine grit wet sandpaper may be required to remove excessive grout haze. Always, protect cement tile from oil and acids that will severely damage it.

If you liked this post, you might also enjoy Removing Grout Haze in a Cement Tile Installation.
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