The main weakness of timber fence posts is that they are susceptible to rotting at ground level. We often have to repair entire fence lines which have collapsed as a result of one or two posts rotting just above the concrete plug. With regular treatment this process is drawn out but inevitably wooden posts will rot and 99% of the time, only at ground level.
Hardman and Oakley Fencing are suppliers of a brilliant innovative product called the Postsaver which is a bitumen cover fitted around the post at ground level. These covers are very cheap to buy and only add £5 to the cost of each post including fitting. They will typically DOUBLE the lifespan of a timber fence.
Take a look at http://Postsaver.com for product details. We carry a sample with us and are happy to show you when we come to quote.
Fencing Contractors and Landscaping 