Patterned floor coverings sometimes have a repeat in the design at regular intervals to allow for pattern matching.

This enables you to trim the sheets to match up the pattern at cross joins, but it also means that you have to build in an extra allowance for trimming.

Here's an example. Let's say that a sheet product is 2 metres wide and has a pattern repeat every 300 mm.

How many lineal metres of material are required?

Step 1: Calculate the length allowance for each run

If the seam runs across the width of the room and each run is 3650 mm, then the number of pattern repeats will be:

3650 ÷ 300 = 12.1

So we'll need to allow for 13 pattern repeats in order to start each run at the beginning of a pattern. This means that the length allowance is:

13 (pattern repeats) x 300 mm = 3900 mm

Because 3900 mm gives us plenty of allowance for the 150 mm return in the doorway, we don't need to add any extra for that run.

Step 2: Calculate the number of runs

The number of runs is:

        7500 (w/w) ÷ 2000 (width of the roll) = 3.75, which means there will be 4 runs

Step 3: Calculate the lineal metreage

The total lineal metreage for the floor is:                                                                                         

       3.9 m x 4 = 15.6 l/m