Ben wrote:
I'm looking at building a woodworking bench for myself and have
familiarised myself with the plans that are sold on the internet. All
the Kits and commercally availiable, ready built benches feature fine
lumber of 3+ inch thickness for the top - be it birch, beech or other.

Since I am operating on a smaller budget, I was wondering what reasons
are there why a sheet of plywwod - 3/4" or 1" oak or birch supported by
doug. fir (4x) lumber would not be used?

The classical woodworking bench is designed for use with hand tools.
This means that you generally have substantial vises that need to be
mounted, that you'll be pounding with a mallet on the bench, and that
you'll be using bench dogs.

These are all more convenient if you have a heavy, strong, solid top.

That said, you can certainly get away with laminating sheet goods for
your top. I'd suggest at least two layers though, and three would be
better.

Chris