America does more "stick-built" construction than some countries, since we retained more of our forests longer (old-growth forests are a vanishing breed, but we haven't yet killed off the softwoods). So it's been important for us to have standardized construction-lumber sizes... which are misleadingly land inconsistently labelled but which are still based on inches and feet.

Elsewhere things have gone somewhat differently. For example, the UK has lost almost all its woodlands, which may be part of the reason folks there are now more likely to build in brick. And they were smart enough to go metric long ago.

Hence my question: are there standard construction-lumber sizes outside the US, and what are they? Or is the US exporting enough pine that our pseudo-2x4's and 4'x8' plywood have become international standards despite the inconvenience?

(I'm explicitly neither assuming there are international standards, nor that there aren't, because I simply don't know. If this starts turning into a complicated/long list, of course it can be pulled to community wiki or wherever... but let's see if there are more than three or so sets of data before assuming that's needed.)


I guess the question I was really trying to ask was whether the metric universe had standardized a set of common off-the-shelf dimensions across countries that would serve as an equivalent of the American sizes for purposes of plan dimensions -- if an American shed is mostly 2x4's on 16" centers with 1/4" 4'x8' sheathing (some of those being real measurements and some nominal), is there a well-accepted set of metric dimensions would replace those elsewhere to build the equivalent shed, and are those subject to the same kind of inconsistency?

An answer of "almost; there are three such systems battling for dominance and they are..." or "not really, everyone has their own set of numbers influenced by their own historical construction practices" or "actually, there IS an international standard known as..." would then qualify as a clearly acceptable answer.

As I say, the real question is whether we can translate something between metric and American in any reasonable way, or if we just have to count on everyone making their own adjustments.

(Let's see, in stones/furlongs/fortnights that would be...)

  • I'm not sure this question is specified adequately. It either assumes that all countries outside the US use the same lumber sizes (which may not be the case), or it is a bad question because it has multiple definitive answers which are equally valid. If the latter turns out to be true, it might be more appropriate to convert it to a community wiki and create a list of lumber sizing characteristics by region or country.
    – rob
    Jul 7 '15 at 15:32
  • Thanks for the edit, but the question of what constitutes a good answer is still unclear and it seems that any answer would be equally valid. I also don't think the suppositions about importing/exporting lumber belong in the question, or at best they should be part of a separate question. Perhaps rather than asking for the sizes themselves and getting a separate answer for every country, you could ask if there is a reference that lists the common sizes of dimensional lumber by region.
    – rob
    Jul 7 '15 at 20:52
  • @rob: does the clarification help?
    – keshlam
    Jul 10 '15 at 7:06
  • So basically, you are looking for something like Eurocode 5 (DIN EN 1995) which is binding for all countries in the EU. (Note that this doesn't necessarily mean you'll be able to buy the exact same dimensions in a shop nearby). It may be a challenge to find an online copy of that for free...
    – Damon
    Jul 10 '15 at 9:37
  • @keshlam The original part of your question seems to conflict with the new part in that you first state that you don't want an international standard, then you state that you want a standard for the metric universe. Also are you asking for a building code or a wood manufacturing code? If you want to know an equivalent code, you should cite some US code that defines whatever it is you want to define, then ask for the equivalent codes outside the US. However, because codes may vary by region and even by locality, I still think the "too broad" and "any answer is equally valid" problems apply.
    – rob
    Jul 10 '15 at 16:32

In the UK, sizes of planed pine (P.S.E) is based on old imperial sizes but marked and sold in metric (mm). The sizes are usually actual dimensions but sometimes are somewhat nominal (i.e. size before planing)

Here's some sizes I found in my pile of offcuts ...

label 18 x 33. actual 18 x 33
label 50 x 22. actual 46.5 x 21
label 16 x 46. actual 14 x 44
label 92 x 10.5 actual 92 x 10.5

The lengths are mostly multiples of 300mm (close to 1 foot) e.g. 1800, 2400 etc.

An interesting source of information about UK timber is diyfaq

Although Britain lost almost all its woodland over the millenia, in the last 100 years the Forestry Commission carried out reforestation of large parts of the UK. See Forestry Commission - Sitka Spruce


In Australia, most framing is 90 x 45, 90 x 35, 70 x 45, or 70 x 35 mm. Floor joists are 190 or 120 x 35 (or will someone correct me on that; they do seem to vary...).

By 4' x 8' plywood do you mean composite beams, like used over windows etc.? There's plenty of that in use, I think mostly 42 or 58 mm think and in heights of 90, 110, 130, 150, 170, 200, 250, 300, and 400 mm.

I don't think I've ever bought north American wood in Australia other than 2nd hand Oregon that came over many years ago (before we figured out how to grow pinus radiata in plantations — which, I gather, we now do rather well). Hmm, there's a thought: do yanks call that nice soft redwood stuff 'Oregon', or is that the same silliness as us Aussies calling our bedsheets 'Manchester', and risible from your point of view?!

  • Plywood is sheet goods that is normally sold in 4' x 8' sheets in thickness from 1/4" (6.5mm) to 1" (25.4mm). The composite beams that you're talking about is what's called Laminated Veneer Lumber (LVL) and usually comes in 2"x dimensions (2"x6" to 2"x24" or as specified by the design engineer). It could be used for headers over doors, windows or garage doors, or for floor joists. LVL beams can be composed of several 2x4 pieces, or of a multitude of thin layers (each a few mm thick).
    – FreeMan
    Jul 7 '15 at 13:51
  • 1
    What I'm more interested in is whether there is a significant difference between nominal and actual size, as is the case with dimensional lumber in the US. For example, if you buy a 90x45, is it really 90mm x 45mm, or is it closer to 85mm x 40mm?
    – rob
    Jul 7 '15 at 15:20
  • That nice soft redwood stuff is not called Oregon in the US. It is called redwood and almost all of it comes from California.
    – Ast Pace
    Jul 8 '15 at 5:20
  • FreeMan I read that as 4x8 inches, sorry. Equivalent sheets here are 1200x2400. rob: No, they really are the dimensions they say (other than the usual moisture variations etc.). AST Pace: I thought that might be the case! :)
    – Sam Wilson
    Jul 8 '15 at 8:29

Lumber (fir and pine, or "needle wood, unspecified") in Germany doesn't come from the US as far as I know (rather local growth or from e.g. Sweden). France has huge supplies, too. The entire department Landes is one big pine forest, more or less.

24x44 and 24x48 and 48x48 (approx. 2x2in) are common, also 40x60 and 60x80 or any combination of 40, 60, 80, 100, 120, and 140mm.
x160 is widely available in thickness greater than 80.

24x74 and 44x94 (approx. 1.7x3.7in) are common for some odd reason. 17x36 is being sold, but not very common, also 70x70 and 90x90 are being sold, and I've seen 24x40mm as well as 34x54.

Available lengths are almost always 2000 or 3000mm, rarely 2500mm, and very rarely something different. Length is rather a guideline, however (not only because of wood shrinkage), though you usually get a bit more, rarely less.

On the other hand, you can get hardwood (almost always birch, rarely oak or chestnut) in every combination of rectangular size (and round, too) in steps of 5 millimeters up to about 60mm, either 1000mm or 2000mmm long, sometimes 2200mm.
Some home centers will shamelessly cheat you on that, however. I've recently bought what I took for "1 meter" 20x20 hardwood, which turned out being 90cm long. Ask me how I found out. Surprise.
When I went back to complain, I was shown the tiny print which indeed says "900mm".

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