I have some 6x8 logs left over from my log home which was built recently. The log are around 16 feet long. I want to use them to build a walking bridge across a ravine on my property. They are untreated. I plan to rest the ends of the log on either side of the ravine. Since the log will rest on the ground and be exposed to the weather, I need to prepare the log in some way. Perhaps I could just put some exterior water repellent stain on the logs. I am looking for suggestions on how I can weather proof the logs.
While I'm not an expert by any stretch of the imagination, I'd suggest building stone "cribs" to rest the log ends on, thus keeping them out of direct contact with the soil. Sealing the ends with "Anchorseal" or a similar compound would really extent the life of your logs. I'm sure that someone wiser than me will be along with a better idea. Your idea sounds cool though. I used to live in the "gully lands" of West Tennessee, and often wished for a way to level out my walks in the woods.
get them really dried out and paint them with a mixture of diesel and used motor oil and maybe a splash of roofing tar. Do this 3 or 4 times and they should last just fine. Never tried it, but its supposed to work pretty good. I doubt it does the environment any favors. Also getting the logs off the ground with some concrete footings would probably be a good idea too