Monday, February 2, 2015
Eastern Red Cedar
I had a reader ask me if I was going to cut and use Cedar posts for my new fencing project, they mentioned that it might be a good way to greatly reduce the costs. A very valid question and a fair assumption as well because if I could find enough Cedar trunks to use it would greatly reduce some of the costs over standard pressure treated posts.
Cutting and using Cedar posts is not a topic I am inexperienced in either. I have been cutting and sinking Cedar posts since before I was allowed to use a chainsaw actually. Most of the posts I help sink 40 or more years ago are in fact still standing today although the fences at the old place could stand to be replaced.
No the problem with Cedar posts today is that pretty much all the good Cedar trees have already been used and the trees that may in fact be of sufficient size just haven't quite developed into suitable post material yet.
Allow me to explain. You see Eastern Red Cedar trees live a very long time. Up to 850 years or so, and although they can sometimes grow really fast the heartwood takes a very long time to truly develop no matter how fast the tree itself and the sap wood grows. Cedars I also understand pull more CO2 out of the air for growth than normal trees which means as those levels increase since the 50's the speed of growth for the trees themselves picked up but it didn't increase the speed that the heartwood develops.
If you take a look at the picture above you can see that many of the trunk sections have a very large band of sapwood. The sapwood does not contain the chemicals which grant the Cedar the rot resistant qualities it is well known for. What happens is that the sapwood begins to rot and in turn that makes the smaller sections of heartwood rot as well. What you need for a proper Cedar post is the smallest band of sapwood around a big heartwood section you can find.
There are several trunk sections in the above picture that would work well for posts. Unfortunately however I have not seen a Cedar cut around these parts that didn't have a wide sapwood band in decades.
Many old timers have told me that second growth Red Cedar is not suitable for fence posts, including my Father actually. What I think is that the generation of the tree makes no difference as to it being a good tree for fence posts but what matters is that the tree has allowed to become quite old, say 200 or more years of growth to get a large enough heartwood section covered with a thin sapwood band. My theory is also that a couple of centuries of these Cedars being harvested for posts has pretty much reduced the numbers of suitable trees around here to nill. At least for the next 100 years or so.
Of course I am not a Cedar tree botanist but I can tell you that the last time I was involved in a big Cedar post cutting project the posts didn't last even five years. Yet posts we had sunk prior to that are still useable. There certainly maybe other inputs I am unaware of but the sapwood to heartwood comparison so far fits the facts of my theory.
Anyway to make a long story short I haven't used Cedar for a while due to the last few failures and the sapwood theory is the best I could come up with. Perhaps your mileage may vary. In a pinch or a grid down situation however Cedar posts maybe the only viable alternative so they shouldn't be discounted but I would recommending checking the sapwood band before putting any Cedar posts in place.
Keep Prepping Everyone!!!!