2x4... actually?

[nikirushka]

Just curious: here in the UK, "2x4" isn't actually 2x4. Often it's more like 1.5x3. Something like 38x89mm.

Is that the same in the US, or when you say 2x4 (or 4x2 ) are yours actually 2x4? So 50x100mm or thereabouts.

I'm still looking at options for building an indoor pond, and as it'll be somewhere around 2500-300l (660-790 US gal ish) and 3ft deep along the same basic design as the plywood tanks with a timber carcass, I want to make sure I'm building it strong enough!

 

[jjohnwm]

In Canada at least, a 2x4 actually measures 1.5 x 3.5 inches. I seem to recall reading that 2x4 inches was, at one time, the "pre-dressed" dimensions of the wood, before being finished down to its final form. We have had the metric system applied to us with the subtlety of a sandpaper enema for decades now, but when anybody goes into a lumber store today, they always buy "2x4's". Asking for the metric equivalent will get you nothing more than a dirty look from the attendant as he reaches for his calculator...

Similarly, plywood still comes in 4x8-foot sheets, in thicknesses of 3/8, 1/2 and 3/4 inch...but they have managed to convert us far enough that the thickness is now listed in mm. So we buy a 4x8-foot sheet of 19mm plywood...but it's actually still 3/4-inch, which is actually 19.05mm...but since that's too awkward...and the 4x8 moniker never changes...ah, who knows?

 

[nikirushka]

Oh ok, I see! Thanks