This article may spark lively debate by some and be viewed as passé by others. It represents generally accepted practices and industry recommendations as contained in the American National Standards for Ceramic Tile Installation (ANSI A-108) If you are signatory to a contract in which ANSI is referenced, then you have an obligation to follow the guidelines. So just what do these guidelines say? Here is the wording of that section:
Workmanship, cutting, and fitting
A-3.3.1 Center and balance areas of tile, if possible.
A-3.3.2 An excessive amount of cuts shall not be made. Usually, no cuts smaller than half size should be made. Make all cuts on the outer edges of the field.
A-3.3.3 Smooth cut edges. Install tile without jagged or flaked edges.
A-3.3.4 Fit tile closely where edges will be covered by trim, escutcheons, or other similar devices.
A-3.3.5 The splitting of tile is expressly prohibited except where no alternative is possible.
A-3.3.6 Maintain the heights of tilework in full courses to the nearest obtainable dimension where the heights are given in feet and inches and are not required to fill vertical spaces exactly.:
A-3.3.8 Nominal centerline of all joints should be straight and of even width with due allowances for hand-molded or rustic tiles.
Centered and balanced can be a challenge for me and I am certain every other installer when you walk into a job with a hall, kitchen, pantry, and laundry room. On commercial work, you may have the pleasure of adding some integral base and trim to make it even more fun so where do we start the process? For floors, my pick is the center of the largest room, preferably one with an outside wall if there is a choice available. Outside walls tend to be square with each other and you can get better measuring points. Interior walls can be pretty hit and miss. I am not sure that I have ever seen a perfectly square room where everything is in alignment. What we are trying to establish is a reference point, not necessarily a starting point. Unlike some types of flooring, the center is not always a good place to start as we cannot work on the installed product.
Once we establish our reference lines we can move the starting point to wherever we wish. When doing multiple rooms that adjoin, our reference line should extend through those rooms as well when possible, using our largest room as the basis. If the doorway alignment does not allow for establishing a continued line we can do it later in the layout. Once we have selected the room in which we are going to start, we need to locate the center. To do so is simple enough; just measure the halfway point across the room from two locations as far apart as possible and make a sharp pencil mark at the measurement off the selected two walls. I usually draw a circle around my marks so they do not disappear on me. The we want to snap "lines" with our caulk box. The common colors used are white, blue, and red. Inevitably, the first line you snap will in all probability either get moved or not used. That being the case, I usually use white or blue caulk, Red caulk is a stain and nearly impossible to remove. I have done tearouts on decades old buildings where the red caulk lines were still visible at various points. This is not an area of right or wrong, just preference. Before you start snapping red, make sure it is your final adjustment. Once we establish our reference lines we need to check and make sure the lines are "square" to each other. If one line is not at a perfect right angle to the other the tile will start doing what is called walking. That is a condition that occurs when one tile is not perfectly parallel to the other. To check for square, you may either use a carpenter square or even better, when checking a larger area, use the 3-4-5 method. A long time ago, a man named Pythagoras proved that the square of the hypotenuse was equal to the sum of the square of the other two sides. To help in his proof, Pythagoras used a 3-4-5 triangle. His methods are used to create an accurate right angle. Measure exactly 4 feet out on one line and 3 feet out on the other and the distance between the 2 points should be exactly 5 feet. If not, you will need to adjust the line till it is perfectly square.
Now, before we move on let's chat a bit about how we can make life a little easier. Snapping lines is a very traditional way of doing layout. Pull a piece of string straight, and it will be straight, but the walls are rarely straight. That causes us to go into a ritual of snapping and re-snapping lines making a chalky mess until we come up with a perfect right angle. Owners or contractors readily remember the caulk mess if the job does not come out as visualized. Here is a chance to dazzle them with your brilliance and dedication to your craft, use a laser! When lasers first came out they were very expensive but have become much more affordable. The average age at our shop when we bought our first laser was late 30s to early 40s. You know that saying you can't teach an old dog new trick? It took about 3 years to integrate their use into our working habits, kind of like the 100-dollar grout buckets. But, like the 100-dollar grout buckets I mentioned in a previous article, once they learned how to use them, they were addicted. Another big plus we found in using lasers was convincing customers prior to installation how out of square some areas were. They are always skeptical of caulk lines, but never had one argue when I used a laser to show out of square or level conditions. It can easily save hours on a multiple room layout. Another thing we used them for often was to show customers their outlets were askew on backsplashes, not our tile. There are a lot of positives to including their use in layouts and checking your work easily. The only negative is accuracy; they do occasionally require re-calibration after being bounced around. Some don't take kindly to bouncing at all!
Once our reference point is established it is time to see what size tile we have on the perimeter, doorways, and cabinets if any. While a half tile everywhere is our goal, it is rarely possibly to achieve so we need to look for areas where we will make "sacrifices" to the balance of our installation by using smaller cuts. There are occasions, normally in architecturally controlled commercial work, where this is not allowed. In those cases, where no alternative layout exists, we may use what is refereed to as a "Dutchman." A Dutchman is 2 pieces of tile cut to take the place of a small cut over 2 pieces. If for instance, you were using 12-by-12 tile and had a one inch cut at the wall, you would take and add the one-inch cut to the 12-inch dimension for a total of 13 and cut 2 tiles at 6 1/2 inches. That would be the technically correct way of dealing with the small cut. In the real world, unless that cut is highly visible, the small cut would no doubt be accepted and in most cases preferred to a Dutchman. One of the easiest ways to check your tile dimensions during a layout is the use of a "jury stick" or "idiot stick" These are common terms for laying out tile in a long line spaced with the desired joint width. This makes an easy reference available to use for measurement as you check the rooms for balance. Otherwise, you may get a serious math exercise.
Once you have established beyond a shadow of a doubt what size all the cuts will be, we are ready to determine a starting point. As long as you measure well you can start your tile work anywhere convenient for you. Most professionals do what we call "grid the floor." In griding the floor, you take the tile and add the grout joints you need, make a mark as far as you can comfortably reach and snap a line. You do that in all directions to you have established a grid. The most common error in this part of layout is not adding or in some cases, subtracting a grout joint. Why not just use spacers? Well, time and lack of reference points. Spacers are great for some applications, especially vertical or maybe even layout. But one thing is certain, all tile varies in size to some degree. Spacers will not allow for that variation and it can easily throw the installation "out of square." Using a grid system allows for some movement to accommodate irregularities. One area of concern when using a grid system is burying the lines under setting material. Everyone has their own method of doing things. Most of those I have ever worked with use a straight edge and trowel over their lines but leaving two windows open to set their straight edge on. Yes, it means you have to clean the thinset off it often but then you are assured you will have setting material under the tile and avoid callbacks due to chipped or broken edges and corners. One last little tip about using a grid system. As you work the lines, keep a carpenter square or one of the "made for tile installation" squares available to keep checking your work as you go. Set it against your straight edge and make sure you have perfect alignment to your floor grid.
There are many common practices done everyday because there are no tile laws, hence the reason we have none of the much sought after tile police. Some are good, some are bad, some are just lazy installers or those who cannot add and subtract. There are some practices because they are expedient to the owner in getting the job done. Only one thing remains certain, beauty is in the eye of the beholder or he who signs the check, not necessarily your check. In absence of other instruction balanced cuts are always a safe bet.