More than once I've bungee corded 2 x 4s to my bike.
Another trick is that I have all the lumber cut at the store.
For that ladder a Bikes at Work trailer would be handy.
Or just figure out a hitch to attach one end of the ladder to the bike and bungee the other end of the ladder to a hand truck and use it like a trailer.
Here are some other things you might try. Have you checked in at the utility bike forum. They can probably figure out a way.
