Changing Building Materials to Metric

[maradcliff]

With the thread about metric conversion I got to thinking about construction. Having dealt with cars that have both sae and metric bolts is a pain in the butt, but I see a much bigger problem. All standard construction in the US has studs spaced at 16 or 24 inches. A sheet of plywood, sheetrock, etc is usually 8 by 4 feet. Roofing shingles, carpetting, linoleum, are all sold in yards, feet or inches. Plumbing pipe is one half, three quarters one inch and so on.

We cant just change these things, and it would be totally rediculous to have separate building materials for both inches and centimeters. How can we ever change this? I surely dont want to buy a sheet of plywood or sheetrock that wont fit across my 16" walls or floor studs/joists. And if we keep the size the same, but change to metric measurements, instead of saying a 4 by 8 foot sheet of plywood we would have to say a long decimal equivalant with POINT something at the end.

Something like carpeting or linoleum probably could be changed to the nearest whole metric number because it does not rely on spaced studs or joists, but then if a room was built to be 12 feet, and the flooring ends up being a half inch less because of the conversion, many people would be quite angry. So, they darn well better make it larger, not smaller.....

Then comes the plumbing pipe. It MUST fit the old pipe. We can not just change to the nearest metric number. And I'd sure hate to have to go to the store and ask for a 3.856 by 5.891 CM electrical box, when I can not ask for a 3x5 box.

Then comes dimentional lumber. It's bad enough we now have 2X4's in buildings that are 2" X 4" 1 5/8" X 3 5/8" 1 1/2" X 3 1/2". Lets not make this worse by adding yet another mismatched size, because the number has to be metric.

I think building materials should just be left as they are. Even if they were to leave the size as it is now, but change to metric numbers, do you really thing many people would ask for that "3.856 by

5.891 CM electrical box"? I'd probably not even be able to remember all those numbers.

About the only place in building where I could see the change not being a real problem would be with liquid measurements. For example, a gallon of paint or a quart of roofing cement.

And finally nails, screws, wire, etc..... I am going to turn this into a question.... Is a #16 common nail 16 cm long? Is a #8 screw a metric number? (of course the length is still in inches). Is a #12 guage wire in metric, or what does that "12" mean? I'm just guessing on this, I dont know metric well enough...

Mark

[Toller]

The rest of the world managed it.

[Edwin Pawlowski]

Most of the molding machines we buy that are metric use standard pipe sizes of BPP sizes readily available. We make and export Insulating Concrete Forms (ICF's as

) to Canada and sometimes Europe in standard US sizes and they work with them OK. I doubt we will ever see a pure metric society.

[PanHandler]

Not much of the rest of the world had to change anything. They've been doing everything in metrics right along. The problem would be if they had to convert to the English system. They don't specify "3.856 X 5.891 electrical boxes - they're probably called 4 X 6 boxes, the CM being taken for granted.

[Jesse]

In Canada the change to metric (somewhat) happened some time ago, today most materials are still standard. However hardware, fuel etc. ids sold by kg and litre and alows them to charge more for less. From my view it had a bit to do with merchandising and maximizing what the market could possibly bear. jesse

[marson]

I also don't think people realize that there are actually advantages to the english system. for example, what if you had to find the center of a window opening that was 32 5/8" you can come up with 16 5/16 in a flash. try it in metric without a calculator. Also, there is the issue of precision. at various times, you might need precision within a 32nd, 16th, 1/8th, and so on. with metric you have mm, cm, and meters.

It's also not true that the whole world has managed. I have a friend in Chile who tells me they have converted to metric, but not in building materials.

[Toller]

Exactly. Had we done it when the rest of the world did it would have been easy. Had we done it when it was required by law (1970?) it would have been harder. Doing it now would be harder still. Doing it 20 years from now, hardest.

Of course, we can wait until the rest of the world finds we have lost our economic power and they no longer have to accomodate us. Without much of an economy, it will be easy.

[Tony Hwang]

Hi, Metric system is far more accurate. One reason Rusia beat U.S. going to moon. The sooner the better going to metric. Kids today learn metric in schools.

[Toller]

Our share of the global economy is rapidly diminishing. It is just a matter of time when the rest of the world decides that dealing with English measurement to accomodate us is just too much trouble.

[Tony Hwang]

Hmmm, You mean Imperial system is more accurate than Metric? I am afraid not!

[PanHandler]

First of all, they would have specified that window opening as 84 cm not

83.625 cm, so halving it is pretty easy. The decimal system is a cinch to work with. As far as precision is concerned, try microns or nanometers!

[kevin]

That's like saying writing in ink is more accurate.

[RicodJour]

You're missing the beauty of the whole system. Right now you're doing conversions when you need more accuracy, and more complicated conversions. If you are measuring a big distance you speak of miles, and think 5280 feet, if it's a room sized distance you talk of feet, and think 12 inches, if it's the width of a board, you think inches. If you need to be more precise you have to switch to fractions (remember the fun you had learning fractions as a kid?).

Now compare that to the metric system where to increase or decrease the unit of measurement you just change the name of the unit, and think 10

- either multiply or divide. There are no decimal points necessary to deal with as you just change the unit of measurement. The unit of measurement is the decimal point. If you want to stick with a particular unit, you'll have to use a decimal point, but the conversion is still less complex than dividing by 12, 5280, 16 or whatever.

Now, about your point about plywood - I'm glad you brought that up - how thick is 1/2" plywood? It's 7/16", not a full 1/2", and that works out to .4375". Do you ask for .4375" plywood, or even 7/16" plywood? Of course not. It's rounded off as a convention. Everyone learns that the first time they use a building material. Whether it's a 2"x4" not being either 2" or 4", plywood, or whatever. You've already learned to make that mental conversion and don't even think about it. The only time you need to think about it, say when you're building up members or sheets, you remember it and make the mental adjustment. Metric plywood doesn't work that way. The number designation for the thickness of metric plywood indicates the actual thickness - no conversion necessary.

Read this:

A lot of the older houses I work on have studs that are close to the full 2" thickness for lumber, and the actual height for the old materials is also greater than the current materials you buy. You know it, and you just deal with it.

Maybe they'd change the size of the box, or maybe you'd just ask for it by a rounded off number designation. They could call it a B series box. It really doesn't matter.

That article I linked to goes into that. Right now I have to shim out, or cut down to make current materials match up with the old stuff. How would the situation be any different. I'm not that old of a guy, and I've seen the nominal lumber and plywood sized drop significantly. When I started out a 2x was 1 5/8" thick, then they dropped to 1 9/16", now I'm seeing 1 1/2". This is before shrinkage! It's like the "improvements" that candy bar makers make when they make the bar smaller and the packaging larger. You know, annoying!

Wouldn't have to.

That's another idiotic thing about the measurement system we use. We use 16d nails, the d stands for penny, and we ask for a 16 penny nail, even though the letter designation is the wrong letter and the penny hasn't had anything to do with the size of the nail for over a century. A 16d nail is ~3.5" long, which is 8.89 centimeters, you'd just ask for a 9 cm nail. Since the 16d nail doesn't relate to anything about the nail _anyway_, they might keep the name and it wouldn't matter. You'd still know it was roughly the right size.

Getting your mind around an idea, particularly one that seems to represent a major shift in thinking, can be problematic. Switching to the metric system would be one of those situations where the thought and apprehension beforehand would be worse than dealing with the different dimensions once the conversion to the new system had been made.

R

[PanHandler]

Here's a handy little free tool I use all the time, called the Phoxel Unit Converter:

It covers everything from length to cooking units.

[RicodJour]

Neither system is more accurate. The person or apparatus taking the measurement is either more or less accurate.

I thought we only had one moon. Wasn't it the Apollo mission that set foot on the moon first?

R

[PanHandler]

SORRY - expired URL, here's the correct address:

[RicodJour]

Convenient that you chose an even number easily divided by two. How about dividing 33 cm by three? That's just as equally arbitrary and meaningless example.

How is that a difference? Making a semi-unit conversion is certainly not easier than moving a decimal point. To add this string of numbers

3/16" + 1' 5/8" + 37 yards 31/32" you have to find the greatest common denominator and convert all of the others, so you have to doing multiplication above and below the line, plus you have to convert yards by that not very convenient 3. In metric, adding this string of numbers 33 cm + 112mm + 42 m only requires you to add the requisite number of zeroes to the greater-unit numbers.

You're also ignoring the obvious fact that you are _already_ using the decimal system. Say you need precision greater than 32nds or 64ths, what do you do? You move to the bastard metric system and start using hundreths and thousandths. Now the two systems converge - where greater accuracy and precision is required, they both resort to just moving the decimal point. No conversions necessary.

R

[RicodJour]

I use an online converter:

R

[Tony Hwang]

Hmmm, Anyone has 8 fingers? 16 toes?. LOL! Real logical numbering is binary.

[Chris Lewis]

According to :

The above are purely arbitrary naming conventions, they don't have any direct relationship to specific measurement systems.

And how long is a 16d nail anyway? First, you need to know what _kind_ of nail it is. Back when they were really measured that way, you also had to know the inflation rate.

And just how big is a barrel? It depends on what you put in it. There are dozens of different size "standard" barrels in the US alone.

SAE/Imperial grew by accretion by a whole host of arbitrary "measures" which weren't measures of the relevant things. I mean, indicating nail length by how much a 100 of the things cost more than a century ago? Is that silly or what?

The value of metric is that all of the measures (length, weight, volume etc) are directly related by simple rules. And secondly, things specified by metric are actually based on _measurements_ other than bizarre centuries old irrelevancies.

Wouldn't it be nice to know how big a #36 or "A" drillbit is without having to resort to a book?