Brick lines come in a variety of lengths and thicknesses. Below is guide to the most common sizes to help you decide.
Length
Brick lines can be purchased in sizes typically between 18m and105m (60-345ft). However, you can get longer lines up to 500m (1640ft). It’s always better to get a longer line and only use part of it rather than purchasing a short line and find out that it’s not long enough.
18m (30ft) line
There are 18m (30ft) lines available which would be suitable as a reference guide for laying bricks on short walls, patios, and for general smaller tasks.
76m (250ft) line
76m (250ft) lines can be purchased which would be ideal for use with large landscape gardening projects, plotting ground layouts for foundation work, and jobs where the line needs to be long enough to wrap around corner posts or stakes.
105m (350ft) line
Larger lines upto 105m (350ft) are available which would enable you to tackle nearly all big jobs where a brick line is needed, although it all depends on the size of your project and your specific requirements.
Thickness
The most common diameter for a brick line is approximately 2mm. Thicker lines can be bought but are generally used for tasks where a more robust line is needed like marking out ground on a busy building site.
Strength
Brick lines need to be robust enough to withstand being untied, wrapped around stakes, and pulled taut across bricks, sometimes over large distances. Many lines are tested for strain to see how much weight pressure they can take before stretching or snapping.
On average, a braided nylon brick line can withstand 65-80kg (140-180lbs) of weight pressure. Twisted lines are slightly weaker and have a strain weight of 45-60kg (100-130 lbs). Thicker gauge lines will be able to taker greater strains.