On Sat, 02 Jun 2018 23:44:02 GMT, david
m wrote:

I am building a foot bridge over a creek. I don't want to try and sink
footers/posts in the creek itself, I am wondering how long a 2x12 can span.
I am able to find 26 foot treated 2x12's locally. If I sandwiched two of them
together on each side of a say a 3 foot wide foot bridge would that work? The
ends of the bridge will be treated 6x6 posts (so 4 total). The span between
posts will almost be the full 26 feet. My question is:

1. is this safe?
2. is the perfect?
3. is this overkill?

Thanks
David

The easy answer is engineered trusses. You can do that with 2x4s in
most cases. The trick is finding someone who can assemble them with
stainless truss plates.