Sign 1Tiles that sit at different heights
Run a bare foot across the field and you catch an edge. In low sun the shadow line along each raised edge makes the whole surface look restless.
What went wrong
This is lippage, and on large-format porcelain it usually traces to two things: mortar that was not fully embedded under the tile, and a bond pattern with too much offset. Large tiles carry a slight crown, so a 50 percent offset lands the high centre of one tile against the low corner of its neighbour.
What it required
ANSI A137.1 allows 1/32 inch of lippage for joints between 1/16 and 1/4 inch. The TCNA recommends a maximum offset of about 33 percent for large-format tile — which is why a 30 percent running bond is the working standard on porcelain pavers, not the 50 percent brick pattern.



