When to Use Grout or Sealant at Inside Corners on Tile Installations
Grout placed in a joint that is subject to movement will crack.
Photo: Scott Carothers.
When discussing products such as grout and sealant, the placement of them seems pretty simple. Grout goes in the grout joints and sealant goes in the locations designated as movement accommodation joints by the design professional or engineer, but sometimes it doesn’t work out as planned.
Let’s look at what the American National Standards Institute (ANSI) and the Tile Council of North America (TCNA) Handbook tell us about movement joints, specifically interior inside corners.
ANSI has several sections that clearly direct the design professional, the general contractor, the person bidding the project, and ultimately, the tile installer or finisher where the movement accommodation joints are to be located along with the necessary requirements.
- ANSI A108.02-4.4.2 Movements joints area requirement for tilework.
- ANSI A108.02-4.4.3 Movement joints shall be kept free and clear of all setting and grouting materials.
- ANSI A108.02-4.4.5 Install sealant after tilework and grout are dry. Follow sealant manufacturer’s recommendations.
- ANSI A108.01-3.7.4.1.1 Suitable sealants include silicone, urethane, and polysulfide.
The TCNA Handbook provides the following under EJ171 Movement Joint Guidelines for Ceramic, Glass, and Stone:
- Change of plane, interior-movement joints required at all inside corners.
- Interior: Change of plane – same as grout joint, but never less than 1/8”.
Given this information, the installer or finisher has everything he or she needs to install the movement joints. Unfortunately, sometimes these joints do not get installed as specified for several reasons; they were not called out by the design professional, someone missed them on the drawings, the installer or finisher was not instructed as to which joints get grout and which ones get sealant. Whomever is responsible is important and needs follow up, but the bottom line is that the grout placed in a joint that is subject to movement will crack as seen in the attached photo. This otherwise nicely installed tile, with well-done inside corner fold cuts, now appears to be less than what should be expected.
“You can take a mediocre tile job, detail it well, and be acceptable, but you can also take a top-notch tile job completed with poor attention to detail, which will be unacceptable.”
The problem with this seemingly minor issue is that a future tile consumer sees the cracked joint and may believe that all grout cracks and may not choose ceramic tile for their next project. Additionally, for the tile contractor, it means a callback and lost revenue.
Attention to detail is critical to the success of any installation. The cracked grout joint is one thing, but look at the bottom on the photo to view the messy grout work. The tile instructor at the trade school I attended once told me, “You can take a mediocre tile job, detail it well, and be acceptable, but you can also take a top-notch tile job completed with poor attention to detail, which will be unacceptable.” Think about it and do it correctly the first time.
This article was originally posted on www.floortrendsmag.com.
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