Question for Canadian Woodworkers

[Bernie Kopfer]

I am curious about wood dimensioning using metric in Canada. Of course inches and feet are readily converted but I was wondering when you go to the lumberyard to purchase what down here we would call4/4 or 5/4 etc, what is the “Canadian” equivalent? 3/4” thickness is of course very common for many furniture pieces what is the common metric equivalent? 19 or 20 mm? Or19.1mm? It would appear to make for complicated ultra precise measuring and cutting on complicated structures built off non metric plans.
And when we buy ‘ 2x4’ etc what is your equivalent? Our lengths are in feet, so when you build a house what is your nominal inside ceiling height? Do you copy our “standard” that you have to turn into metric or do you have your own? I’m thinking of dimensions for door and window widths and so on.
I most certainly am not trying to say one system is better than the other, but do wish we were metric too. And living next to a big English system using country must create some interesting problems.

[Doug Garson]

I'm not in the home building trades but pretty sure it is almost completely imperial dimensions. Dimensional lumber is the same both sides of the border, a 2x4 is 1 1/2" x 3 1/2" except for rough sawn full dimension lumber which is just that. I just bought some rough sawn full dimension 2x4s and 2x8s and the 2x8 was slightly oversized almost 8 1/8" . A lot of our lumber is exported to the US. Nails screws etc are all imperial in diameter and length, there are metric nuts and bolts but they are in the minority. We don't use your penny system for nails (I find the penny system odd), your 16 penny nail is 3 1/2" nail, much more logical. Plywood is generally 4x8 sheets, thickness is metric but often sold as the nearest imperial equivalent. Most common ceiling height is 8 ft, some are 10 or 12 ft in higher end homes.
Although Canada went metric decades ago us older Canucks still think in imperial, the youngsters think metric. We buy are gas and milk in litres and drive distances in kilometres but if you buy a tape measure, the majority are imperial, you have to look for a metric one. It's not as different as you might think. When you sleep next to an elephant, you .........:cool:

[Rod Sheridan]

Hi Bernie, Doug Garson gave you some great answers.

Material is mostly Imperial as Doug said, except for plywood thickness in North America which is metric.

We went metric in the 70's, and as I was in post secondary in the 70"s, I never learned the Imperial system except for simple things. ( I can do a few calculations in Imperial however science and technology are metric).

I design all my own furniture in metric, no 19mm is too difficult, I use 20mm as it makes calculations easier, or 35mm or 50mm.

If I'm building a fence I buy 6' X 6" posts, and cut them to length in metric. I have a couple of Imperial tape measures, very rarely used.

I own a mish mash of vehicles, a couple in Whitworth, lots in Metric, none in Imperial.

Really, very few people know anything about either the Imperial system or the Metric system, for example people often indicate their weight in Kilograms, which isn't a unit of weight.


Regards, Rod.

[Anuj Prateek]

I am curious about wood dimensioning using metric in Canada. Of course inches and feet are readily converted but I was wondering when you go to the lumberyard to purchase what down here we would call4/4 or 5/4 etc, what is the “Canadian” equivalent? 3/4” thickness is of course very common for many furniture pieces what is the common metric equivalent? 19 or 20 mm? Or19.1mm? It would appear to make for complicated ultra precise measuring and cutting on complicated structures built off non metric plans.
And when we buy ‘ 2x4’ etc what is your equivalent? Our lengths are in feet, so when you build a house what is your nominal inside ceiling height? Do you copy our “standard” that you have to turn into metric or do you have your own? I’m thinking of dimensions for door and window widths and so on.
I most certainly am not trying to say one system is better than the other, but do wish we were metric too. And living next to a big English system using country must create some interesting problems.

At Windsor Plywood, lumber is sold in imperial. On plywood, dimensions are written both in metric and imperial.

[Bill Dufour]

Volvo Cars used American sized fasteners up until the 1970's. I think they switched overnight to driving on the right before they switched to metric.
Bill D.

http://realscandinavia.com/this-day-in-history-swedish-traffic-switches-sides-september-3-1967/

[Doug Garson]

Volvo Cars used American sized fasteners up until the 1970's. I think they switched overnight to driving on the right before they switched to metric.
Bill D.

http://realscandinavia.com/this-day-in-history-swedish-traffic-switches-sides-september-3-1967/
Actually most American made cars today use metric bolts and have ,I think, for decades.

[Doug Garson]

At Windsor Plywood, lumber is sold in imperial. On plywood, dimensions are written both in metric and imperial.
I think the Canadian plywood is made to metric thicknesses and the imperial thickness is a soft conversion, by that I mean it is approximate. To compensate for this, router bits for plywood dadoos are sized to match the plywood actual thicknesses which in most cases is slightly less than the imperial dimension. For example 6mm plywood is labeled 1/4" and is actually 0.236". https://cwc.ca/wp-content/uploads/2019/03/Plywood-Sizes.pdf

[Grant Wilkinson]

At all the local lumber yards, rough sawn is sold at 4/4, 6/4, 8/4 etc. I've never seen any mention of metric equivalents. We buy sheet goods in 4 x 8 or 5 x 10 sheets. They are actually about an inch larger in both dimensions so we can get a good, square 4 x 8 or 5 x 10 out of them. Thickness seems to vary depending on the supplier. Some is a true 3/4", some is 19mm.

[Jim Becker]

I"m not Canadian. I use metric. I don't worry about how material is sold because I"m going to dimension everything myself anyway in the shop. It doesn't take too much to mentally convert to inches for board foot calculations and sheet stock is what it is.

[mike stenson]

for example people often indicate their weight in Kilograms, which isn't a unit of weight.
.

Since most people are measuring their mass at 1G, and weight is a measurement of gravitational force, it's really splitting hairs.

Besides, it's more or less about not understanding physics ;)

[John Gornall]

Here's a Canadian wood supplier - don't think there's any metric:

https://www.westwindhardwood.com/product-category/hardwoods/

[Mike Kees]

So here is my take. As a carpenter working in the trades my entire adult life we use imperial exclusively on the job. Feet and inches. Our material is all standard 4'x8' basically because we share the longest undefended Border in the World with The U.S. which happens to be our largest trading partner for softwood lumber products. So we will probably never have metric dimensioned sheet goods (length and width). In reality we are permanently caught between two systems ,so one just learns to roll with it. At my shop I thickness to 20mm for finished thickness on most of my projects. As far as which system of measurement is used ,Both. Depends on what I am doing. Cabinets set heights are based on imperial norms,counter 36'' high. However box widths could be either metric or imperial.

[Doug Garson]

Here's a Canadian wood supplier - don't think there's any metric:

https://www.westwindhardwood.com/product-category/hardwoods/
If you search a bit you'll find the plywood is metric thickness, the epoxy is in litres, the Dominoes are in mm and of course the pricing is metric :D but yes rough sawn lumber is imperial. We are really a mixed bag. For example, BC Ferries states max vehicle weights in Kg but length, width and height limits are in feet and they ask you to park within 6 in of the vehicle ahead of you. Provinces are metric (we have 10) but territories are imperial (3).

[Mike Kees]

Doug I grew up in the Yukon and it is definitely not imperial. Metric started in schools in the 70's. Just like the rest of Canada.

[Doug Garson]

Mike, I agree we are officially metric and that's what's taught in school but in reality we are still a mix. Construction lumber is a good example, still imperial, sheet goods like drywall still imperial length, width and thickness while plywood is metric thickness only. If the US had gone metric when we did we would be full metric but when your biggest trading partner is imperial you end up where we are.

[Alex Zeller]

What would 4/4 lumber be in metric? 25/25? If so would 5/4 be 31/25? 50 by 100 doesn't really roll off the tongue like 2 by 4. When I was in England they called sheets of plywood 8 by 4.