building round wood timber frame structure, what are the reasons for removing the bark?

I've been researching a round wood timber frame building and all the pictures online seem to have the bark removed.
This seems to be a lot of extra work for no obvious benefit to me. Does anyone have a good for and against list for this??

Thanks

Sam

The short answer is:

1). Insect damage

2). Messy

3). Promotes rot

Most insect damage, not just termite damage as you might think, but all kinds of insects are attracted to wood that has decaying bark. There is a stage after the tree is cut, and before the bark falls off on its own, that insects are attracted greatly to the wood. By removing the bark first, you mitigate the effects of insect damage to the wood.

At the same time, as mentioned before, as the wood dries the bark inevitably falls off. Not always in sheets and at the same time, so it ends up being really messy. Since this is about a year later, it coincides with when the house is being outfitted inside and really can make a mess. It is not the end of the world if you don't mind cleaning up lots of mess now and then, but debarking first can avoid a lot of mess.

As we all know bark on a tree protects the trees, but after felling that bark also expedites rot. Since the tree is no longer growing, but the bark still ensures the tree stays wet, it can promote rot. This is why an unbarked fence post rots faster then a peeled one.

I had the same thoughts as you at first, and wondered if spending the time to peel the bark off a log was worth it. Now I am trying to come up with a debarking method that is easy to cobble up in do-it-yourself style instead. Kind of going with the thought that spending time up front to come up with a mechanical debarker would be a better method then spending countless hours debarking by hand. In this regard YouTube has various videos on how to accomplish this. I have not seen any I like, but have noticed my bulldozer tracks debark quite easily in the right circumstance so I am curious if I can build something that will enable my bulldozer to do the debarking for me.

At the same time, if you find you must hand debark, doing so now until June is the best time as when the sap is running, the bark peels much easier. You will also want a Spud, a long handled tool for peeling bark.

Hi,
Thanks
I should have given more detail really.
I'm in the UK so termites are not really a thing over here I've got ash trees for the frame and the have been felled just over a year now have dried out quite a lot now. However the bark rather than fall off has dried onto the logs and doesn't separate of the internal wood easily at all. so is it strictly necessary if the wood is mostly dry already. The structure is going to be for a workshop so mess is less of an issue anyway.

I had in mind to use a raised pad under each post for the structure to sit on, so ground water and rising damp shouldn't be an issue.

I'm looking for the most efficient method and wether or not i can justify leaving the bark on.

Sam



 

I have built log and round wood post and beam and would strongly recommend taking off the bark. The insects that will live under the bark, often larvae of beetles, bring fungus that start the rot process.  I use a plainer head mounted on a short chainsaw bar and powered by the saw. If the blades are set at the right height and kept sharp it takes off bark and smooths the wood. I built mine but a commercial version called Log Wizard is available.

Thinking about the structure of a tree, the cambium layer is between the bark layer and the actual wood that makes up the bulk of the tree trunk.  The cambium layer is where moisture and nutrients are carried back and forth from the roots to the ends of the branches.  This part of the tree trunk is alive and constantly active, and so once the tree is cut down, it quickly dries up and shrinks considerably.  That's why its so attractive for bugs to get under the bark layer, and why the bark gets loose once the cambium dries up.  The cambium is the glue that holds the bark to the wood beneath.

There isn't any structural integrity to tree bark.  It won't bear any weight.  As said above, it'll fall off eventually and be a mess.  I suppose that if I were framing a barn with unpeeled logs, it wouldn't be a big thing.  But if it were for a finished home application, I wouldn't want that stuff sluffing-off every time someone bumped into one of those logs.

Additionally, that bark layer will slow the drying process for the logs.  If you want to get your timber dried quickly and maximize the shrinkage right away (so your joints stay tight and gaps do not appear later), removing the bark is necessary.

Sam, besides the things others have already mentioned, If you fasten logs with bark on, when it deteriorates there will be structural gaps left, this will require tightening the fitting or the building will fall down.
This is similar to what happens when building a Log house, the logs settle and you have to make adjustments or you have huge air leaks and the structural integrity is compromised.

The air quality inside will suffer as well, air-born bits of bark are not particularly good for human lungs or any lungs for that matter.
The bark dust will be ever present and it is corrosive when humidity is high. This can ruin your tools that are made of steel or aluminum, even bronze suffers corrosion from bark dust.

Redhawk

What if,

the interior of the structure is completely sealed off from the unpeeled framing (cob doesn't need bark to stay in place) and

there is no bark anywhere there is wood on wood contact in the frame - or the only contact points are the cut ends of logs.

the next bit; promotes rot and insect damage.

I'm wondering, given the log is not going to see any more water or ground contact after cutting, how much insect damage is generally being promoted beyond the thin layer of cambium some larvae manage to eat before it dries out?  
Termites and beetles around here aren't seen in dried wood that is isolated from any water flow.  It might be that there so much wood on and in the ground out here, they don't stray from their preferred habitat.  

I understand that when a roof leak does occur, rot occurs faster if the bark is still there.  Any precise idea how much faster?

Does it matter that it rots faster if leaks are easily detectable, fixable, and dryable, when you compare it to a peeled log you can't see getting damp?

What are the reasons for pealing a log at this point? hrmmmm

John Hutter wrote:What if,

the interior of the structure is completely sealed off from the unpeeled framing (cob doesn't need bark to stay in place) and

there is no bark anywhere there is wood on wood contact in the frame - or the only contact points are the cut ends of logs.

Depending on your climate and the amount of moisture trapped in the logs, I'd still be concerned with mold and fungus growing in those logs. Particularly if you seal it all up with cob prior to adequate drying, I'd think that the cob would absorb at least some of that excess moisture and then gradually break off. I imagine (as this is all a thought experiment anyway) that this would lead to rotted logs in the worst case, and in the best case scenario periodic applications of additional cob would be required, at least until the logs were sufficiently dry.

If there's a way to assure that the logs have been dried, then I'd feel a lot more comfortable in using them with the bark still attached. Otherwise, personally I would spend the needed time in the Spring to peel some logs.