On Wed, 13 Jul 2005 00:02:47 GMT, blueman wrote:

I am building a built-in bookcase with a 48" shelf span and want to
make sure that I am designing the shelving system properly to support
the span with minimal deflection. The shelves need to hold heavy
textbooks.
I would like to avoid adding shelf-pins along the back because I don't
want visible holes. Also, I would prefer not to split the span since I
like the open look and don't want to have 2 narrow 2ft spans.

Questions:
1. Is this construction strong enough to support a 4 ft span loaded
with textbooks?

We built a library for an attorney who wanted his bookcases as large
as possible with adjustable shelves. Our limit, because of sheet
goods, was 4' wide with shelves basically 46 1/2". We told him that
there was a possibility the shelves could sag but that we would try to
make them as strong as we could.
We ended up gluing 2 layers of 3/4" oak veneer core plywood together
then put a 1 1/2" x 3/4" routed oak face on both the front and the
back of the shelves. We told him that if the shelves did sag he could
just turn them over. The bookcases are full of big ass law books,
been there for ten years and he's never turned them over.

Mike O.