[Greenbuilding] Sustainable Post & Beam Construction
RT
archilogic at yahoo.ca
Tue Oct 29 12:16:21 CDT 2013
On Mon, 28 Oct 2013 21:20:17 -0400, beatrice dohrn
<beatricedohrn at yahoo.com> wrote:
> SOunds like you are talking about a log home, which is worse than post
> and beam. Post and beam is not great, but it doesn't gennerally
> connote timber walls....
If the comment "Post & beam is not great" is a criticism of post & beam
joinery being inferior to timber-frame joinery, then I would agree.
However, if the comment was intended to mean that framing that uses large
dimension timbers instead of industrially-processed 2x dimension lumber
isn't a good idea, then I would disagree.
God (and the Devil) is in the details.
If the negativity re: large dimension timber frames has to do with a
notion that they consume more wood, then I would argue "Not necessarily".
My own 30 yr-old home is a timber-framed hybrid -- R-44 exterior walls,
R-72 roof .
All of the timber framing is exposed to the interior.
The use of large-dimension framing members is offset by the fact that the
members can be spaced further apart so that the total amount of wood
consumed is the same as conventional 2x framing. However since the trees
were sawn up into little strips, there wasn't the volume of wood lost to
sawdust with each saw kerf and less energy consumed for sawing.
The trees that provided the timbers were harvested from with a 100 km
radius of the building site. Industrially-produced 2x dimension lumber
typically comes from many hundreds or thousands of kms away.
Less transport energy.
I hand-planed and joined all of the timbers on site, without using any
power tools (a conscious choice) and air-dried them in situ, thereby
avoiding the energy consumed for milling and kiln-drying of 2x dimension
lumber.
Framing that is done with 2x dimension lumber is typically so poorly done
that even if Code allowed it to be left exposed, you wouldn't want to be
able to see the butt-ugly, disrespectful manner in which the wood was
treated by the builders.
I could go on but I won't.
Moving on to log-walled structures, I agree that generally-speaking, they
aren't all that great from a Green perspective.
However, in my neighbourhood there are many such structures (including
cordwood) which are over a century old and have been inhabited
continuously over that time. I am confident that many of the homes built
in the last 50 years or even 10 years, will not be able make that same
claim.
Down the road from my home, in the heart of the village of Carp, there is
a log structure built by its owner well over 40 years ago. An inspection
of the exterior corners would reveal that it appears to be a genuine
dovetail-joined log structure as opposed to one of the pre-fab kit
buildings that dot the neighbourhood.
Inside, the log walled interior would do nothing to dis-spell the
impression that the exterior gave.
The reality is that the owner ripped the timbers to create an exterior and
interior log veneer and put an R-20, air-sealed 2x6 stud wall between the
two skins.
That saying about "Generalisations are always wrong (including this one)"
would seem to apply.
--
=== * ===
Rob Tom AOD257
Kanata, Ontario, Canada
< A r c h i L o g i c at Y a h o o dot c a >
(manually winnow the chaff from my edress if you hit "reply")
More information about the Greenbuilding
mailing list