Should I allow more for herringbone?

Yes. Every board along every edge is cut at an angle, and the offcuts are harder to reuse. Allow more than for a straight lay; the pack's instructions usually say how much.

Wastage allowance explained: why 10%, and when to allow more

Q: Is 10% a standard?

No. There is no British Standard for flooring wastage. Published figures range from about 2% for a straight lay of long boards to 15% for patterned boards, and 10% is where most ordinary straight-lay guidance sits. It is offered as an example you can change.

The wastage allowance is the extra you buy on top of the measured area, because boards get cut and paint gets touched up. BuildBatch starts both at 10%, labels the figure as an example, and lets you change it.

What the allowance is for

For flooring:

Every row ends in a cut, and the offcut only starts the next row if it is long enough.
Boards around pipes, door frames and awkward corners are cut and sometimes spoiled.
A damaged board in the pack, or a mistake.
A spare board or two for a repair later, because a later batch may not match.

For paint:

What stays in the tray, the roller and the brush.
Touching up a thin patch, and the second visit to a wall that dried patchy.

Why 10%

It is not a standard. There is no British Standard for flooring wastage; the measurement rules treat waste as a pricing matter, not a quantity. Published figures range from about 2% for a straight lay of long boards to 15% for patterned boards, and 10% is where most retailer and manufacturer guidance for an ordinary straight lay sits. For vinyl and LVT planks, two makers give figures, read on 29 September 2026. Quick-Step’s vinyl product page says to order 10% extra to make up for cutting loss. Amtico’s Click Smart Parquet guide says at least 15% for a room under 10 m² and 10% for larger areas, and more for narrow or awkward spaces. Laminate, vinyl or engineered wood: what changes on your list sets them beside the other makers’ figures. The same 10% example is offered for vinyl, and labelled as an example.

The 10% for paint covers waste and touch-ups. It is an example in the same way, and the tin’s own guidance replaces it.

When to allow more

Allow more, and let the pack’s instructions decide how much, for:

Diagonal or herringbone laying. Every edge board is an angled cut, and angled offcuts rarely fit anywhere else.
Patterned or tile-effect boards that have to line up from row to row.
Long boards in a small room, where few boards go down whole.
Awkward rooms with many corners, alcoves, pipes, bays or doorways.
Your first floor, where mistakes are part of the job.

BuildBatch warns when the flooring allowance goes above 25%, but it accepts it. Above that, check the figure is what you meant.

When 10% may be plenty

A straight lay in a plain rectangle, long runs whose offcuts start the next row, someone who has done it before. Even then, keep a board or two back.

What the allowance must not do

It must not stand in for area you did not measure. The returns of a chimney breast, an alcove or a bay are area, and they belong in the measurement, not in the percentage. An allowance covers cuts and waste; a missing wall is a missing wall.

Worked example

A floor of 15.12 m² and packs covering 1.84 m².

Allowance	Area to buy for	Packs
10%	16.632 m²	9.04, so 10 packs
15%	17.388 m²	9.45, so 10 packs
20%	18.144 m²	9.86, so 10 packs
25%	18.9 m²	10.27, so 11 packs

In this room anything from 10% to 20% buys the same ten packs, because the tenth pack already brings 18.4 m². Rounding to whole packs does more than the exact percentage.

Paint works the same way. The example room’s walls need 6.897 L before any extra. In 2.5 L tins alone that is 3 tins at 0% and 4 tins at 10%, because 7.586 L is just over 7.5 L. Mixed tin sizes soften this: with 1 L, 2.5 L and 5 L tins the room refresh finds 8.5 L instead of 10 L.

What this guide does not cover

A figure for your particular product or pattern, which only the pack’s instructions can give. Sheet vinyl and carpet, tiles laid to a particular layout, and how a professional prices waste on a commercial job.