I would like to construct a very simple footbridge over our creek. The
distance is around 12-14 feet from bank to bank. I figured on using two
16' pieces of lumber as the support (about 18-20 inches apart), with 1x6
decking boards along the top. About 2.5' to 3' wide.

My question is what should I use for the support beams. I don't want it
to get too high off the ground, because we would like to easily ski over
it in the winter.

I was conteplating either using 4x6 lumber or 2x8 lumber. I'm not sure
which will provide a stiffer bridge - which is what I want. How much
weight can I expect such a bridge to hold? Should I be using a third
support beam?


Thanks.

-Jonathan