posted 13 years ago
Wooden posts - fence or column - conduct water upward when placed in the natural upright position in which it grew. Reversing the position - small end down, large end up - minimizes moisture conduction.
Due to the abundance of termites in our area - East Africa - we plastic coat the portion of posts to be placed in the ground. We scorch the ground end of a post over a fire - not burn, just scorch. Then we wrap that portion with plastic grocery bags and heat the wrapped end over a fire. If the plastic ignites and burns - too hot. Just want it to melt/shrivel and adhere to the post. Another technique is to heat oil in a cauldron and put chipped plastic in the oil. If the plastic ignites, the oil is too hot. The plastic melts and floats on the oil. Depending on the grade of plastic, you will get a thick liquid or a glob. If liquid, the post end can be dipped into the floating plastic and the plastic adheres. If globs, it can be smeared on the end of the post using a flat spatula-like stick. (For long-term permanent structures, we set the posts in concrete. The plastic treatment is used for long-term temporary. Posts used to last less than a year before termites hit them. They do not bother the plastic lined posts, but have attacked some above ground.)
Caution: There is serious potential for severe burns when melting plastics in hot oil. Make certain the vessel is stable. There is very little fume/toxic gases released by melting plastic but smoke from burning plastic is hazardous. Err on the side of caution, wear a mask.