Whether you're re-roofing your whole house or taking on a small DIY project, taking accurate measurements could mean the difference between a good-looking finish and a leaky home. Whether you're purchasing materials or receiving a quote from a contractor, every home renovation project requires understanding linear metres – and its cousin, the square metre.
What Is a Linear Metre?
A linear metre (or lineal metre, as it's sometimes known) is a way to measure length along one dimension – and it's not as complex as it sounds. In fact, they're the simplest way to measure the length of your materials.
Whenever you got your ruler out at school or unroll a tape measure for your latest DIY venture – that's a linear metre. Quite simply, it is length measured in a straight line. Lineal metres don't account for width or height, making it an ideal measurement for materials like roofing sheets, timber, or guttering. Often these building materials are sold by price per linear metre.
When Should You Use Linear Metres?
As you might have gathered, you've likely been using linear metres without knowing it. In your construction or DIY project, however, you might come across lots of other units that might seem more complicated. So, when should you fall back on the simple linear length in your home improvement projects?
- Metal roof sheeting
- Polycarbonate sheets
- Guttering and downpipes
- Timber beams
- Flashings
Other examples of when linear metres are primarily used as your measuring device:
- Carpet rolls, timber flooring, and other flooring products
- Fencing
- Pipes and cables
- Fabric
Essentially, if the material's width is fixed or doesn't affect your project, the linear metre measurement is the most efficient approach.
How to Calculate Linear Metres
To calculate a linear unit of measurement:
- Measure the length: Use a tape measure (a ruler also works for a smaller, rigid stretch) to measure in a straight line.
- Convert units: If your measurement is in centimetres or millimetres, you'll need to convert to metres to get your linear metre (100cm = 1m, 1,000mm = 1m)
Let's look at an example.
If you take a measuring tape to your roof and measure five metres along the front and back and three metres along the sides, then the linear measurement is 16 metres.
Tools You'll Need to Measure Linear Metres
- Tape measure: A basic tool for most measurements.
- Laser distance measurer: Ideal for long distances or hard-to-reach areas.
- Measuring wheel: Useful for measuring lengths over large areas, like fencing or pipelines.
- Digital calipers: To precisely measure smaller objects.
Mistakes to Avoid When Calculating Linear Metres
Linear metres are easy and straightforward to measure. However, as with anything, there are a few common mistakes that can lead to over- or under-ordering materials:
- Ignoring overlaps: Roofing sheets often require overlaps, which can add to the total length needed.
- Measuring in the wrong units: Make sure all your measurements are converted to metres for consistency in calculating total costs.
- Not accounting for waste: Always order a little extra material in case of error, otherwise, you'll end up without enough materials.
Double-check your measurements or talk to a professional if you're not sure.
Why Are Linear Metres Important?
Linear metres are commonly used to calculate any measurement in a single direction in the building industry.
Linear metres are important for…
- Cost estimation: Suppliers and shops often price materials per linear metre. Estimating costs helps you budget and plan effectively. When a contractor talks to you in linear metres, you'll understand what they mean and be able to make the right decision.
- Efficiency: Knowing the exact length reduces waste, so you don't buy too much (or too little) material. Estimates also help you stay on schedule and within budget.
Is a Linear Metre the Same as a Square Metre?
No, a linear metre and a square metre are not the same. The key difference is:
Linear metres measure length in a straight line.
A square metre describes the area (length × width).
For example, a roofing sheet that is exactly one metre wide and five metres long covers five square metres and is only five linear metres long. Whereas, a sheet that is five metres wide and five metres long is 25 square metres, but still only five linear metres.
What Is a Square Metre?
A square metre (often seen as 'm²') is a unit of area equal to a square one metre on each side. It's used to calculate the total surface area of a space, like a roof or wall.
To calculate square metres:
- Measure the length and width.
- Multiply the length by the width to get the area in square metres
For example, a roof that is 10 metres long and six metres wide is 60 square metres: 10 x 6 = 60.
Converting Linear Metres to Square Metres
To convert linear metres to square metres, you'll need to know the fixed width of the material – once you have the length and width, you can get the square metre measurement. Use this formula:
Square metres = linear metres × width
For example:
Linear metre: 5
Square metre = 5 × 2
Square metre = 10m²
Final Thoughts on Linear Metres
While they're called lineal metres, this is a simple unit of measurement that we've all been using long before embarking on DIY roofing projects. Understanding what the term means will help you make sense of quotes and plan your renovation more efficiently.
FAQs
What Are Five Linear Metres?
Five linear metres refers to a straight length of five metres. It's commonly used for materials like roofing sheets, timber, or guttering – or things like how much carpet you need for your flooring project.
How Many Metres Is a Linear Metre?
A linear metre is simply one metre. The term 'linear' means that it's a measure of length in a straight line, as opposed to a square metre, which covers the area.
Does Using Linear Metres Produce More Accurate Measurements?
Yes, linear metres provide precise figures when measuring lengths. However, for coverage or area, square metres are a more appropriate measurement.
Is It a Linear or Lineal Metre?
Both the 'linear' and 'lineal' metre is correct and means the same thing. However, 'linear metre' is more commonly used in the building industry. You might see American companies call it a 'linear meter', which is just a different spelling.