Yes there is less labor, and there is some strength gained, but this is a double edged sword, such pieces usually fare quite well as purlins, but they are found almost as commonly as joists. When used as groundfloor joists, where they are subjected to the moisture that is perking up out of a dirt floor they oft'times suffer rot problems, sometimes even without a nearby leak, and often not seen in a fully hewn piece right next to it.

A Desibu is a scribe term of French derivation, a detail where the nose of a brace is clipped back so it's shoulder does not have a (somewhat fragile / somewhat dangerous) knife edge.

And they don't have a color in any real sense, this was just a nonsense question floated (and my twisted sense of humor) to see if it might elicit a response - Thanks for asking.

If you google "desibu" you will get some deviant art forms, it makes me wonder?

This round timber also has me wondering about log homes. There is a lot of sap wood on these structures and half of it is exposed to the exterior weather. To rid ones self of any sap wood will help you sleep at night if nothing else, or at least it helps me. Sap wood is a curse we have to live with. I must not leave out the point that many log houses were built with squared up timber, they knew what happens to the sap wood. It is the more fancy modern log homes that leave me suspicious.

Tim

Will

Like many things, the double-edged sword is a point well taken. I had not been aware of sapwood being so rot-prone

The question of sap and rot aside, suppose you do flatten the joint locations on a round wood frame, as Mo originally suggested, making scribe locations flat...was I thinking correctly about the referenceability issue: the perimeter of a frame needs this, etc, and that round stock makes squaring and plumbing (not to mention scribing depth, etc) somewhat unworkable?

I think Chrysler should name their next small car the Desibu

I'd want a blue one.

Perhaps another reason the old timers liked boxed heart timber:

1. no sap (rot)
2. checks and splits will not cross the heart
3. balances any inherent stress w/ in a timber

I googled it too, which wasn't much help.

And Wikipedia doesn't have an entry for desibu.

Maybe it should be added to the TF glossary?

Hey,

Off topic, but sounds a lot like "besigue".

always wanted one of these.



and a hat like that...

Look at the design values for log beams vs timber beams. I'll have to find where I stashed the log code but the log beams have higher base design values if <1/10th the diameter is skimmed off the top. The "chord" of fibers is largely intact vs running out of a squared timber.

Eric Sloane commented that it looked like old time carpenters thought that removing knots strengthened timbers, they had hewed them out of many joists, even though this might not be helping in our view.

i don't think hewing only one side is beneficial... doesn't that incur differential drying? (unless you wanted the timber to crown...) isn't this the the 'sponge that is wet on 1 side' curling up problem? wood likes to equalize - unless you are cutting FOHC from really large trees (or small pieces from smaller logs) - boxed heart would make the most sense to equalize the drying forces and balance out the sapwood to each side of the timber... no?

2 of the barns that i surveyed and moved had 'sleeper' joists for the first floor - hewn 2 sides -top and bottom. bottom was pretty rough - top was 'flat enough' for the floor boards to go down on. the barn we used as a shop had 3/4 rounds in the floor - hewn only on the top, 'flat enough' for the floor above. another large barn in PA we dismantled had pole rafters, but hewn timbers.

i'm not sure if 'the old timers' - masters and ideal builders as some want to hold them up to be - had a consistent system for this. it certainly would seem to vary by region, species available, and size of logs.

Master builder or not I believe it was done, or in this case not done, in the name of efficiency. You don't see round joist in the living area even covered with lath, which brings up a secondary reason for square timber, uniformity in finishing plaster. I have noticed hewn surfaces on timber that was sawn, this was done to bring a fat area into plane. As mentioned before the cellar usually had poles for joist with a lime wash, brighten and assisting in preservation. The humble builder traveling the country side building barns most likely didn't have a calculator to check the statistics of his timber, something else was built in though. Same thing happens today.

Tim

sure. i'd bet that most were making the best of the material on hand, using what knowledge there was about how long, how big, and how far things could go. you wouldn't cut down a 40" tree to make a 6x8. you'd optimize the best you could what the land could give you with what you needed in size.

sometimes this worked out... other times, in terms sizing - it didn't. plenty of undersized timbers, odd joinery, etc. in the barns i've seen. i'm sure there are plenty of examples lost to history as well.

i certainly don't want to piss off ourbarns1 - yes - there were many 'masters' of their craft and they deserve respect and study - but my sense is that people are people no matter when in history one studies their lives or their works, and as there are today folks building to a minimum standard - there were folks then building 'just good enough' with what was available - and this includes how / why they decided to hew, what joinery they cut, etc. etc. etc.