What reasons keep architects or designers placing square floor tiles grout lines at right angles to the direction of travel?

Labor cost to install wall tile

TL;DR They do, but its expensive!!,Firstly, tiles used in a u201cbasicu201d floor install are not laid out in the direction of travel, they are laid out along the longest wall (which also happens to frequently be the direction or at a right angle from the direction of travel).

,So why lay tiles along the edge of the longest wall in a room? In the US and Western Europe a major part of the cost of a tiled floor is the labor cost to install it, and a big part of the time needed to install the tiles is measuring and cutting the tiles to fit the flooru2026,Take a look at this room (ignore the u201ctrimu201d thats another u201cpremiumu201d feature),Notice that whole tiles were laid against the left (and presumably the bottom) edge of the room.

Because tiles come in fixed sizes (for example 12u2033 or 18u2033 squares) and rooms do not, the tiles at the top and right edges of the room have to be custom cut by the installer.

,So roughly 1/2 the tiles along the outside edge of the room have to be custom cut.

,Now look at this roomu2026,All the way around the room tiles have to be custom cut! Plus, because the tiles are angled 2x as many tiles make up each edge! That will take up to 4x longer to dou2026,Its all about costs.

Offset tiles cost more money to install.