When it comes to measuring, Richard Renouf advises you to use whatever’s best for you, but be consistent. If you mix metres and centimetres in the same notes it’s easy to make a calculation mistake.

DOES the ‘hook’ end of your tape measure wobble? I hope so, because this isn’t a fault as many people assume, it’s a feature to improve the accuracy of the tape depending on how you’re measuring.

If you push the tape up to a wall, the tab should slide into the end of the tape giving you a flush reading, but if you’re measuring along an object, it slides out so the tape itself is flush with the end of the object. This is a great feature if you’re doing precision work, but it’s unlikely to make any difference when measuring for flooring.

Many estimators choose to use laser measures rather than tapes. Although highly technical inside, these are really simple to use. Hold the measure against a wall and press a button. A dot of light (usually red) appears on the opposite wall showing where the device is measuring to.

Another press of the button locks the reading which can then be seen on the screen. The result will be in metres to three significant figures (eg 3.457m), which means it’s reading to the millimetre.

A laser measure works by sending pulses of laser light along the beam, then ‘catching’ the reflection. It measures the time the light takes to go there and back and from this accurately calculates the distance the light has travelled.

The forerunner of the laser was the ultrasonic measure which worked in a similar way but used sound waves instead of light. These couldn’t be focused with the same pin-point accuracy as a laser, so sometimes the readings weren’t as accurate as one would hope.

Modern laser measures now have many useful extra features and it’s worth taking the time to consider these when choosing one for your day to day use.

The most basic thing to consider is the distance that the measure can work over. Most will easily cover 30m but models are available which are accurate over a kilometre (and need a built-in camera to enable you to see where it’s pointing!). For domestic work I use a measure which goes up to 40m and I’ve never been stuck even in large commercial premises as I can measure from a fixed point in the middle of a room towards each wall in turn and get accurate readings for rooms of up to 80sq m.

As a gadget freak, I’m usually tempted to get the biggest/best/most expensive available but in this case it would be a disadvantage.

I was recently inspecting a customer’s home and somehow the topic of conversation came on to laser measures. It turned out the homeowner was an international judge for ploughing competitions and brought out a 500m measure for me to look at. It had cost more than £2,000 and had its own tripod and striking plate (a target for the laser beam that would guarantee reflection even over an extreme distance).

Overkill for the average flooring contractor, but would definitely be useful for a surveyor when marking out an entire large-scale housing estate.

A second feature to consider is the size of the screen on the device – or, rather, how many measurements it will show at once. The simplest will only show one measurement, so you either have to remember it or write it down before taking a second.

Mine gives the last three readings which means I can measure length then width even if I have to retake one of the readings. Some models will have larger screens, or will allow you to scroll through previous readings so you have the ability to check back.

Other models will allow you to take a series of measurements and will then calculate the area and/or volume of what you have measured. This can save some time when measuring for a product sold or supplied by the square metre.

Mid-range laser measures tend to come with Bluetooth connectivity. This means they can be linked to your smartphone or tablet so that the readings are imported straight across. There may be software from the manufacturer to turn this data into room plans, or it might integrate into planning software systems that will then go on to create estimates and cutting plans.

The most sophisticated laser measure I have has some interesting physical and software features. The casing has a fold-away tab which, when opened up, acts as a ‘hook’ to hold the device against the end of an object, much like the hook on a tape measure. This saves time and improves accuracy when compared to trying to line up the base with the edge of an object.

The same tab can then be opened up further so that it is sticking out vertically from the bottom of the measure, and the scale adjusts to the extra distance this creates. The tab can be poked into a corner allowing for accurate measurement of room diagonals, for example.

The measure also has a tilt function. This is useful if you don’t have a clear line of sight horizontally to the opposite wall. A built-in function allows you to tilt the measure upwards and the screen then tells you the angle of tilt, the actual measurement taken to the high point on the other wall, and then the horizontal measurement you would have got if you had been able to measure horizontally.

It’s important when using a laser measure to measure for flooring to remember that although the device is measuring to the millimetre, this is a much higher level of accuracy than we need. You’ll save yourself time by rounding up, rather than using all three significant figures.
What unit of measurement should we use? It is perfectly legal to measure and work out estimates using feet and inches (and some laser measures can be set to measure in imperial), but the people for whom this is second nature are reducing in numbers year by year. So do we use metres, centimetres or millimetres? Technically, centimetres are not metric units as the metric system is based on multiples of 1,000 – millimetres, metres and kilometres, although when the metric system was first taught in preparation for M-day in 1974, rulers were produced which even had decimetres (100 millimetres) as a unit on them.

I’d advise you to use whatever is best for you, but be consistent. If you mix metres and centimetres in the same notes it is easy to make a calculation mistake.

Of course, tape measures are still important. Measuring a staircase using only a laser measure is very difficult, and other features such as insets can be measured more easily using a tape.
www.richard-renouf.com
Richard Renouf is an independent flooring consultant service officer