The techniques we've discussed so far have all applied to rooms with a standard rectangular shape.

Now let's look at some more complex situations.

Keep in mind that whatever the design is, your objective should be to treat the whole area as a single overall unit.

This means that wherever possible, the tiles should flow through doorways and take account of internal features without losing the lines you have established for rows.

That is, the tiles should stay 'in bond' throughout the area.

Corridors

The drawing at right shows two rooms with a common doorway and an outside corridor.

To set out this area for a tiled floor:

1. Strike a line down the middle of the corridor (AB).

2. Find the closest midpoint marking the edge of a tile in each doorway (C and E).
   
   You can do this by either measuring multiples of the tile width along the line AB or dry laying an exact number of tiles between these two points.

3. Starting at C, strike a line at right angles to AB into the first room.
   
   Mark a point along this line (D) that matches an exact number of tiles, and allows you to strike a new line through the doorway between the two rooms.

4. Starting at E, draw a line at right angles to AB into the second room.
   
   Mark a point along this line (F) using the same process as for D.
   
   In other words, the length of EF must be the same as CD.

5. Strike a line (GH) across the middle of the two rooms, passing through D and F.
   
   Check that the distance between D and F is the same as between C and E (and again, an exact tile multiple)
   
   Check the distances between the working lines and their corresponding walls to make sure the border tiles balance and there won't be any narrow tile cuts. Make adjustments to the lines if required.
   
   You can then use these lines for laying straight tiles, or for further set-out of diagonal layouts.

Hollow squares

Hollow squares are areas that have an internal square-shaped space that will not be tiled.

They include corridors around a quadrangle, the floor area around internal lifts, or a balcony that runs continuously around a building.

If the floor is to include a feature border or decorative pattern, the tiles must be laid 'in bond' for the floor to be properly balanced.

The first thing you need to check is that the corridors are at right angles to each other.

If they're not, you'll have to use the technique shown below under 'Corridors at an angle'.

Strike a centreline down each corridor.

Measure the distance between points A and B and check that it is an exact multiple of the tile width.

If it isn't, you may be able to move one of the centrelines AC or BD slightly to the left or right to achieve an exact multiple.

But remember, you still need to maintain an even border tile size around the walls of the internal square.

Alternatively, you can 'lose' a little bit of width in some of the tiles along the line AB to pull the last tile back to the centre mark.

Do this by trimming a small amount, say 5 mm, from the last few rows of tiles.

If the trimmed amount is small, it won't be noticeable in the overall job.

Use the same process to set out the tile placement through the other corridors.

Corridors at an angle

If a corridor runs off at an angle, it won't be possible to maintain the bond with the change in direction.

In this case, you should still strike centre lines along the corridors, but where they join the tiles will need to be cut on one side and butted to the last row of tiles running across-ways.

Where a different coloured border tile is used, some clients prefer to block in the whole junction area with that colour to hide the joining line.

Rounded edges and columns

To maintain the bond around a column or other internal object, you should mark out the area by striking lines between A to B, and C to D.

This will allow you to keep laying full tiles in bond, and come back later to scribe and cut the tiles in the blank space.

As always, make sure the lines are perfectly square and accurate in length, to avoid any problems with the rows not meeting up properly on the other side.