Avoid Tile Cracks By Properly Cutting a Hole for Water Supply Lines

Square cuts around a pipe penetration or any square corner cut are a recipe for failure. Either use the appropriate hole saw or pre-drill the corner and cut to the hole.

Photo: Scott Carothers.

First impressions are meaningful, can be long-lasting and can sway a future client’s opinion.

This was the case during the Coverings show in Orlando. In one of the men’s rest rooms, three of the six urinals had cracked tile around the water supply line. There weren’t any nasty cuts peeking out around the chrome escutcheon, but the cracked tile occurred due to the installer’s lack of American National Standards Institute (ANSI) specifications and tile industry best practices.

ANSI A108.02 section 4.3 Workmanship, cutting, fitting and grout joint size lists the following:

4.3.4 Fit tile closely where edges will be covered by trim, escutcheons or other similar devices.

4.3.5 The splitting of tile is expressly prohibited except where no alternative is possible.

In the case of the above-referenced rest room, there was a chrome escutcheon to cover the hole cut into the tile for the water supply line. On the surface, the escutcheon did its job of providing a neat and finished appearance. The problem is not the chrome cover, but the process of cutting the hole in the tile.

The water supply line to a commercial urinal or toilet can vary depending on the local plumbing code, but they normally range from 3/4” to 1” in diameter. The tool industry provides a wealth of hole saws available in just about any size imaginable. In most cases, a 1 ¼” hole saw works well in providing adequate clearance around the pipe while also allowing alignment to the adjacent grout joints. These hole saws most commonly are either carborundum grit, carbide-tipped or diamond-coated. The carborundum saws work well on softer ceramic tiles, but the diamond hole saws can be a better choice for hard porcelain and glass.

Since the operating process may differ from one saw to another, be certain to read the manufacturer’s guidelines since some saws are dry cutting, some are wet-only cutting, while others may be used wet or dry. Running a wet-only saw without water can ruin a new tool in a matter of seconds.

Unfortunately, the tile installer on this job either did not know about hole saws or thought that they are too expensive, which was a mistake. Using a hole saw is much faster than making four wet saw cuts and much safer for the tile. Round holes will very seldom cause the tile to crack.

Conversely, straight wet saw cuts with square corners are a recipe for failure. The square corner cut (or over-cut) weakens the tile body, which coupled with the natural shrinkage that occurs in dry-set mortars while curing, results in a failure as seen in the image. This situation can be made even worse by the use of excessively thick mortar build-up behind the tile.

Remember that a potential client may view these cracked tiles, giving them a negative image of a tile installation, and select something else for their project. Think about it before you make that next questionable cut thinking nobody will notice. They will!

Scott Carothers is the Director of Certification and Training for the Ceramic Tile Education Foundation headquartered in Pendleton, SC, and is responsible for the creation of the Certified Tile Installer (CTI) program, is involved in the creation of the new Advanced Certifications for Tile Installers (ACT) program as well as providing training to others in the tile industry. He has been involved in the ceramic tile industry for over 33 years and was the owner of a successful retail firm prior to coming to CTEF. He has served as President of the NTCA, Chairman of the NTCA Technical Committee and named the NTCA Tile Person of the Year in 2005. He is a voting member of the ANSI and the TCNA Handbook committees. He may be contacted at 864-222-2131 or scott@tilecareer.com.