On Tue, 12 Feb 2013 17:40:57 -0600, Vic Smith
wrote:

On Tue, 12 Feb 2013 13:43:49 -0800 (PST), DerbyDad03
wrote:



I did something similar in SWMBO's garden but I think mine was longer
than 12' 3". I'll have to check tonight. I screwed the heck out of it
using a couple of hundred screws coming at it from both sides. This
spring I'm going to flip it over 'cuz even with all those screws,
after 4 years there's a noticible sag. There's no weight on it, it's
supported at each end, about 6" from the ends.

Gravity sucks.

Making such a small diameter wood "beam" without it sagging probably
takes more engineering than it might seem to some.
That why beam height increases with length.
The best bet is to look for the technical specs somewhere.
Different woods sag differently.
Then you don't get disappointed.
Glued plywood construction probably is the way to go for least sag.
Just my 2 cents.

Not necessary but instead of glue, use a flitch plate with bolts
because he wants to be able to undo the beam if necessary.