Leaving the Bark on Porch Posts

There are several reasons why leaving the bark on an architectural feature is a bad idea, especially outdoors. September 25, 2014

Question (WOODWEB Member) :
I am working on new home construction in west central Ohio. I have taken out 75 plus year old elm or ash that has been in the hay mow for 75 years of a 125 year old barn. They are 20 feet long and 6-9" diameter with the bark on. I would like to use them as porch posts with the bark on. They will be exposed to weather for the first time in 150 years. I'm thinking of spraying them down with a Bora Care and then would like to brush on some type of sealer over the bark to help with the change of seasons. I want to leave the tight bark on. What would anyone recommend treating the new porch posts with?

Forum Responses
(Architectural Woodworking Forum)
From Contributor O:
You are in new territory, my friend. A few thoughts: Ash draws borers unless it is kiln dried - look for little piles of sawdust under the logs. Neither ash or elm are thought of as particularly weather proof, though the fact they are old growth and perhaps have a high ring density will help. Bark is the host for a...host of bugs, bacteria and fungi that want to feast on the wood. I have no experience with Bora-care or equal, but toxicity may be an issue for the humans around the posts.

Bark stays tight to the wood in most species when it is cut during the coldest part of the winter (willow and hickory furniture). The fact that the bark is tight now does not mean that it will stay on once the logs are out in the weather. You can easily observe just the opposite in the woods. Lastly, this is not something you see - you usually see peeled logs. This may be the best indicator yet that it does not work well.

From contributor C:
Contributor O is correct. The bark will eventually fall off, probably after one season of change. Even inside there can be problems. I once had to dismantle a rustic stair railing that used bark on cherry that soon after it was installed, (not by me), the borers appeared, leaving the little piles of dust. We had them fumigated and reinstalled them. We removed them a couple of years after due to the bark falling off and creating a cleaning nightmare. We replaced them with kiln dried peeled bark cypress. I do not know what kind of finish they had used on them.

From Contributor O:
We tend to forget there is an historical reason rusticity was moved away from planed or smooth wood vs. rough sawn or with bark. The bark attracts bugs, and rough wood surfaces are impossible to clean. The biggest difference is that mice can climb on a rough sawn bedpost, but not a planed one. This was all rediscovered again about 25 years ago in this market when, in a move to ever lower residential building costs, rough sawn cedar was introduced as a low cost interior trim. The mice could get anywhere.

From the original questioner:
Thanks for the input. Good point - no one else has it so that must be a reason, or maybe that there are few 80 year old trees that were cut and dragged straight to the hay mow 75 years ago. In the meantime I have 25-10' porch posts with the bark on standing in a shed. I'm a few months off to putting outside posts on a porch. I guess if I did use them I would have some extra seeing I need 12.