How long does a homeowner want a fence to last? Do not think that if a wooden fence post is treated that termites will not attack the wood. Treated posts do not absorb 100 percent of the chemical that helps prevent termite infestation. When posts are commonly installed, the base of the 4 x 4 fence post typically comes in direct contact with the ground, giving termites a clear path. Installing ObeX11 posts sleeves, gives a level of protection that no treated posts can give. These sleeves are available through this website with free shipping to any where inside the continental United States.