So Watt Journal

Plywood Series — Part 1

Plywood Series — Part 1

What on Earth is Plywood? 

You might have noticed that we’re pretty obsessed with plywood, and after a recent discussion on Instagram about some misconceptions on what plywood actually is.

Plywood 101 

The common misconception about this amazing material is that it’s a fake or cheap copy of real timber. Not true! Plywood is made from real trees! More specifically, thin layers of honest timber glued together. You may think it sounds like double-handling, but believe it or not, plywood can be an improvement on a solid timber board.

In the production of plywood, each layer of hardwood is glued in alternating directions. Typically, solid timber wants to bend and warp along its grain direction, so alternating the layers forces the timber to work against itself, making it super strong and less inclined to turn into a boat hull overnight! This technique is called CLT (Cross Laminated Timber). Glues are also added, and depending on the type of glue, this contributes to the strength of the board once it’s all laid up. The Victoria & Albert Museum demonstrate this beautifully in this video:  

Just say you were looking to make a 1m x 2m plywood table top.  You would either need to buy a full slab of solid timber which has been kiln dried (this will cost you an arm and a leg!) or alternatively, you could buy planks of solid timber, but you would still need to glue them together side by side. Or, you can cut it from a plywood board and use the offcuts for legs on your new table!

Plywood Fun Facts

  • Plywood was used for the first time in 1865, with construction and sizes improving steadily until it was industrialised in 1928.
  • Typical board sizes are 2400mm x 1200mm, although you can buy oversized sheets in some species.
  • The thinnest plywood board you can buy is 9mm, any thinner than that and you’ll have bendy ply (which is totally a thing, but it’s not structurally sound).
  • There are loads of different types of plywood, from hardwood to softwood. We use hardwood ply in our work.

    Further Reading

    Thesis from Swedish University of Agricultural Sciences, Department of Forest Products. The thesis work was conducted for IKEA of Sweden, Älmhult. 

    Leave a comment