# Plywood standard…

3063 Views 23 Replies 13 Participants Last post by  Biagio
Maybe this topic had been discussed before, but I couldn’t find a direct answer.
My question is about the manufacturing standards for plywood. In almost all cases plywood thickness comes rated as a rounded number: 1/4”, 1/2”, 3/4”…But in reality all of them are significantly thinner. For example the 1/4” plywood is 5mm, while the 3/4” is only 18mm thick. That is a significant difference. Therefore the question is why?
And, is there any kind of plywood that is made true to size and if so, who sells it?
Also, there doesn’t seem to be a standard about the number of ply for any thickness. At least it’s never specified in stores and in lumberyards.
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In S.Africa 2440mm x 1220mm
That's almost exactly 4' x 8', just a little over but what do you center your wall studs in construction? We use 16" centers, 4 studs for a 4' wide sheet of plywood, drywall etc. but dividing 1220mm by 4 gives you 406.666666mm. The 2400mm x 1200mm that James quoted makes more sense for construction just because it divides evenly. Again, just curious, I know this thread was about the thickness but my mind kind of wanders a lot.
That's almost exactly 4' x 8', just a little over but what do you center your wall studs in construction? We use 16" centers, 4 studs for a 4' wide sheet of plywood, drywall etc. but dividing 1220mm by 4 gives you 406.666666mm. The 2400mm x 1200mm that James quoted makes more sense for construction just because it divides evenly. Again, just curious, I know this thread was about the thickness but my mind kind of wanders a lot.
Sorry, 1220mm divided by 3, not 4. It's 4 studs but 3 spaces between them. I divided right just wrote it wrong!
The 2440 x 1220 measurement is the closest rounded off metric mm rendition of an exact 8' x 4', which would be 2438.4 x 1219.2 so it is in effect exactly an 8' x 4'. Most construction in SA is brick, and I know nothing about stud spacing, but perhaps someone else here can comment on that aspect.
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Like Wildwood says, we do almost exclusively masonry construction, so we know from nothing about framing, studs, etc. Where drywall is used (eg to divide a space) extensive use is made of lightweight steel profiles. The drywall itself is fibre-cement. I have no idea of standard spacing, but plywood is rarely used for this application. Good quality plywood costs a fortune here, whereas drywall or manmade board is more affordable.
Our affordable timber (pine) generally grows too rapidly (large annular rings) to make it either stable or suitable for much other than roof trusses.
I understand things to be different in Australia, where residential construction is more wood-based, but I do not know whether the building technology is the same as in North America. In Australia they can also uplift a house and put it down on another lot - we can't.

BTW, I can understand why the price of good timber is so high here (mostly imported), but what the hell caused prices to spike so much in the USA and Canada?
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