Updated: Nov 21
Back to 1972, 'Metrication', the first NZBE article, by building trades tutor R J Willson on the challenges the industry is about to face converting to metric from imperial standards of measurement and 'Cosmetics for builders', the attention grabbing advertisement, promoting Gib-Tex sprayed application for ceilings "once up, you never have to go back for touch ups".
By R J Willson
There is a new word being bandied about these days which is applicable to every industry and individual in New Zealand. The word is 'metrication' and it will affect the construction industry no less than it will affect the other industries of New Zealand.
The change to the Standards Institute units of measurement for length, weight,area, volume, capacity etc., was inevitable to the rational standardisation of the world's various units for the common knowledge and good. So that a metre in France is a metre in Britain and in New Zealand and everywhere else. It seems a pity that while in some cases the units will be universally standard other units will not be, e.g. dollars. A dollar in Britain is approximately equal to two dollars New Zealand.
Inevitable Metrication might have been - imminent it has now become. A timetable has been given to the various sections of the community so that the S.I. units will be totally in use by the end of 1976. Between now and then a great deal of education needs to be undertaken so that the ultimate S.I. units can be gradually introduced into the system and not at the last moment, thrust upon us with all the effect of an unexpected punch in the breadbasket. After 1976 another milestone of British tradition will be eradicated, gone the way of the pound sterling, although it will not be too hard to imagine the odd craftsman holding firmly to his three foot rule and condemning these 'new fangled ideas.'
Well then, let's look at the situation in a practical way. What is actually happening now, what problems are obvious and how can they be over come?
Firstly, what has been done?
Ask around at various informed places and you will find:-
New unit dimensions are being or have been determined.
New codes are in preparation and will be implemented according to the S.I. timetable.
Assurances have been given by the Metric Advisory Board that the change-over from imperial to S.I. units will be as painless as the change from sterling to dollars, and we must agree that an excellent job was done in that case.
Building apprentices and technicians are being given instruction in the metric units so that by 1976, when the units must be used, these people will have completed their training programme and will be fully conversant with the metric names and sizes. Indeed, at the Auckland Technical Institute at this moment a house is being constructed using the S.I. units of measurements.
One particular problem, that immediately springs to mind is roofing. How will carpenters and pre-cutters determine the lengths and the bevels of the various roof members since the traditional steel square method must fast becoming obsolete? Fortunately, the problem was foreseen and has been solved.Two members of the Building and Allied Industries Department of the Auckland Technical Institute have developed a ready reckon-er from which they affirm any person (within or without the trade) can easily calculate roof lengths and setup any of the various bevels required. This work is in the hands of an educational publisher and will be released to coincide with the S.I. timetable. Another problem is the inevitable one of conversion. When designing a house for instance, it will be hard to convince some people that a 3.50M x 3M is almost the equivalent of a 12'0"x 1O''O" room. It is far better to establish new standard units and do all the measuring and calculating within those units than to spend time and cause considerable confusion trying to compare feet and inches with metres and millimetres.
New standard measurements must be determined for furniture sizes, building elements such as bricks, masonry units, wall lining sheets, doors, cupboards, timber sectional sizes, minimum spacings, the list is seemingly endless. When the new standard sizes have been established it is only necessary to get on with the job using the new measuring units, rules and tapes.
Architects must plan in metric measurements. Draftsmen must draw up using metric scales -1:100 instead of 1/8"=1'0"and soon.The confusing thing here will be to remember that the 1:100 scale represents metres and a metre is nowhere near equivalent to the other standard unit, the foot; and 96'0" drawn to a scale of 1/8"=1'0" should not be measured with a metric scale. However, five minutes with a metric scale and metric dimensions and the competent draftsman is completely at home. It is easier to be exact and the variable measurements can be eliminated. Quantity surveyors must take-off, abstract and bill the quantities required for the same job, but using different units. This should be easier on them as greater use can be made of calculators, and duo-decimals will probably go where all the good duo-decimals have long since gone.And again, though we had little cause to grumble before, complete accuracy is easier to obtain.
Carpenters must build using the metric rules and tapes available. During this interim period, it is sad to note that the metric rules are a combination of one metre divided into millimetres on one side and feet and inches on the other. Full marks however, for the new plastic material of which the rules are made and of the bevelled measuring edge for the metre and millimetres. But as one technical tutor did not say, but did, paint out the feet and inches before confusion results. These rules are being used on the house mentioned previously and it is heartening to see how quickly the younger generation can adapt themselves to the metric units and, as the tutor himself. was heard to say 'They would get hopelessly confused if they had both the S.I. units and the imperial units to work with. This reinforces the argument that the translation of sizes must be completed before the practical work of the job is even started.
Joiners can now work to a degree of accuracy that will satisfy even the most critical of them. Their calls of 3'11 1/16" 'full' or 'bare' as they draw attention to their skill will not now be heard. Heaven forbid, if one of them says 946 millimetres 'full' or 'bare.' Their timber will vary this much in atmospheric changes, and they could not even sharpen their pencils to such a fine tolerance.
Variables there are, and variables there always have been in the building trade. Timber, for example, can be cut to length, the off-cut used for the smaller lengths, packers etc., until finally too small for use it is relegated to the firewood heap. The same can be said for other materials available in long lengths. Volumes have been written about the correct use and the correct amount of waste to be allowed for, but in metres and millimetres as in feet and inches these lengths are versatile enough to enable pipes, reinforcing steel, flat iron products etc., to be made in standard lengths. These lengths will probably be translated to the nearest decimal equivalent as it is unlikely that manufacturers will change lengths or thicknesses of materials after expensive plant and machinery has been set up to produce a building material. The question does arrive however, 'Will those materials conform to the new standards?' And if not, 'Will the manufacturers make a new size by installing new plant or modifying existing plant?' For example:'3'0" wide sheets of wall lining material are ideal for framing members spaced at 18" centres but will the 3'0" wide sheets meet the new minimum spacing requirements? If not, there are two alternatives:
More framing members must be used.
Cut the wall lining sheet to fit.
Neither alternative is completely acceptable.
Other questions which will arise:
Will all the changes to metric sizes happen at the same time? Will all the stocks of imperial sized materials be exhausted at the one time and the metric units take over at a set time?
Will plumbers run a 3" pipe through a 100 mm wall?
Will builders have to purchase imperial sized materials to fit a metric building?
If the answer to these is yes, then the resulting confusion could cause unnecessary errors.
Meanwhile, on wider horizons what moves are afoot:
Will all nations accept and implement the metric standards at the same time, or will they in fact, accept the metric standards at all? There seems to be no move from the United States of America in this direction.
Will there be engineers continuing to calculate in pounds per square inch while others are working in kilos per metre squared?
Will some details in publications be given in 4" x 2" while we use 10'0 x 50 or what ever the standard unit may be?
And what of our traditional records? What of the lengths of site boundaries given in links, converted into feet and inches and back to links again? What of the areas given in acres, roods and rods, poles or perches? This has been done in the past for thousands of building sites. Are they ever to be brought up to date?
The leveling staff, graduated now into feet and tenths of a foot. Will one metre divided into tenths and hundredths be accurate enough for road gradients or drainage levels? (.01M is equal to .39" or slightly over 3/8"). Theoretical men can work to a high degree of accuracy to be sure,but need the excavators, concrete workers, drain layers and roadmakers work to any closer degree of accuracy? If so, there is always the millimetre (accurate to approximately 1/32"), or will the staff be too hard to read when divided into millimetres? There are lots of questions yet to be resolved and field tests to be taken. Answers are required so that everyone works to the same standards. It must not be that some use metres and millimetres while others use centimetres, even decimetres.Guidance must be given here by those who determine the standards. They must also state how they will be used.
How far can we take metrication? There cannot, for example, be ten hours in a day and ten days in a week. Neither will there be 100 degrees in a right angle, but provided everyone works to the same generally accepted standard there is no problem and if metrication of our measuring system is a step towards universal brotherhood, then,on with the march!
By R J Willson 1972.
“Celebrating 50 years of New Zealand Building Economist 1972 to 2021”
By Matthew Ensoll
Editor New Zealand Building Economist.