How can plywood possibly be stronger than particle board? They're both fractured and weaker than the whole plank. They're both wood.?

in particle board, the bond between the resin (glue) and the particles isn't as strong a wood.

Wood in general have veins like structure. These are thread like. In the plywood, these tjheads are made perpendicular by placing the thin layer one cross above like + sign. In bullet proof west the same technique is used. But in particle board. two layers are filled with saw dust. They lack strength of playwood.

Consider the strength of the"glue" used in a) particle board, b) cheap plywood, c) marine ply.

For cost reasons there is hardly any glue used in particle board.

A higher quality is used in flooring which must be water resistant.

A higher quality again in cheap plywood

And proper water resistant glue in marine ply.

Next consider the grain. Wood is strong along the grain. It is weak across the grain.

In particle board the particles are laid at random so that their grain pattern is not oriented for strength.

in 3 ply then at any direction there is always at least ONE layer of wood in which the grain is at its strongest direction. That is increased in 5ply or 7 ply etc.

In building with NON plywood we must design and build the structure so that the forces lie in the strong direction.

In plywood we can be a lot more careless.

PS paper is also wood. But few would expect a house of paper to be particularly strong.

Dust is made of stone. But I would prefer to be hit with a bit of dust than to be hit with a big rock.

The material is not as important as the STRUCTURE that the material is in

Penny. I am using the waterproof chipboard flooring. It holds a water bed amongst other things.

The important part is the framing of the subfloor. On a span of 3.6 m I had bearers set at 1.5 m spacing. Then floor joists above that at 600 mm spacing.

The flooring laid on that is able to support hundreds of kg.

If I had purchased plywood flooring it is made thinner to compensate for the intrinsic strength of the material. This makes it lighter and easier to install particularly if you are installing a floor at some height.

But my flooring is now 40 years old and has withstood every load quite successfully.

The only thing that you can't do is to leave the surface unfinished. Mine is carpeted.

Where the plain hardwood floors only need to be polished.

Plywood is made up of a bunch of flat thin boards that’s been glued together. Each sheet after the next is rotated to that the grains make 90 degree angles.

Particle board are made by sawdust that’s held together by resin.

Since when has something that has gaps between them be stronger than something that’s solid all around.