This has been a hotly debated topic for quite some time with many theories being offered in favor of or against setting posts in concrete. There are many different methods of sinking posts into the ground and depending on where you go in the country, you might see one method largely preferred over another. Along with methods come add-ons like concrete collars and methods like sloping the concrete up towards the post. This usually occurs in colder climates, but to answer the question at hand, let’s first discuss what “rot” actually is and what causes it.
What is Rot?
The thing that causes wood posts to deteriorate and weaken is actually a living organism. Rot is a very hungry organism that feeds itself with wood posts. It typically lives up to about 5 inches above ground level and down to about 8 inches beneath the ground. You won’t often see a post rotted further down than 8 inches below. This is because oxygen is necessary for rot to exist and oxygen becomes scarce the further beneath the ground you go. Any living organism needs four things to thrive and grow: food, water, oxygen, and the proper temperature.
Does Concrete Cause Posts to Rot?
While some think that installing wood posts with concrete causes moisture to get locked into the post, it’s more common to see the rot existing above and below the concrete. Though the rot doesn’t usually occur within the section covered by concrete, it’s very apparent that concrete doesn’t do anything to prevent rot either. The wood post essentially acts as a straw and can suck up moisture from the bottom of the post hole. In the case of treated wood, over time the wood can expand and twist and cause a gap between the wood and concrete, letting in moisture.
For more information about Butler Contracting and the installation of our wood fences, visit our wood fence page on our website!
