As a second-generation remodeling contractor, I’ve seen a lot of design trends. One that seems to have staying power is large-format tile — that is, any tile with at least one edge more than 15 in. long. Whether they’re 16×16, 18×18, or plank style, open any home-design magazine and chances are you will see large-format tiles.

Most of the techniques used to install larger tile will be familiar to anyone who’s ever set smaller tile. Laying out the tile is similar, cutting it is the same except that you need a bigger saw (which can be rented), and grouting it is no different. However, some normal procedures used for installing smaller tile take on heightened importance when working with large-format tile, and there are several differences that are crucial to both the final look and to the longevity of the floor.

Flaws in the substrate can cause any tile floor to fail, but their effect is greater with large-format tile. Also, regular thinset mortar can’t support the size and weight of large-format tile. Large tile exaggerates lippage (variations in the height of adjoining tiles). While inconsistent mortar application and setting pressure are the leading causes of lippage, tile warpage plays a role. Most tile will be warped to some degree, but the size of large-format tile exaggerates warpage. Especially when laying tile in a running bond pattern, where the end of one row aligns with the centers of neighboring rows, installers need to rely on grout joints wide enough to disguise the problem, and even then it can be impossible to achieve an acceptable level of lippage without using a clamping system.

The good news is that although large-format tiles have their own rulebook, manufacturers and the Tile Council of North America (tcnatile.com) offer helpful solutions. Address the above concerns,…