The Book: Your Log House
4. Traditional Principles & Contemporary
I have learned to trust some design
principles, particularly in designing for my region
– the rain-drenched forests of British Columbia.
Log Home Guide editor and
editor-in-chief, Doris and Allan Muir, articulated my
viewpoint in an article they wrote entitled, “Planning
Your Log House.”*
“We have one major suggestion
to offer you on design. One of the most striking features
of most of the world’s oldest log buildings —
in Norway, Russia, Sweden, Finland, and Japan —
is the wide overhangs or eaves of their roofs and the
covered porches that frequently surround the structures.”
“These are not accidental
or purely ornamental (though they add a lot of beauty,
as well as utility). Centuries of experience in those
countries taught the builders that it is supremely important
with a wood structure to protect the wood, not only
from moisture, but also from the equally destructive
ultra-violet rays of the sun. Those houses lasted because
those builders learned the lesson the hard way...”
“… Don’t have
logs protruding beyond the roof line, such as ridge
logs, purlins or rafters. They will rot very quickly.”
The Laftehus of Norway, with its sod
roof, employed this overhang principle and stands as
an example from the 1300s (Figure 1).
The same buildings dealt with sill
log rot prevention in a simple yet effective manner.
Note the built-in drip cap (Figure 2).
Visiting Eagle Crest Lodge on Vancouver
Island in British Columbia, I was dismayed to see protruding
logs with rotting ends. Otherwise the massive, hand-fit
logs were still sound on these turn of the century buildings.
Even though I have already long preached
the gospel of the superiority of solid timber buildings,
I was particularly inspired to write this chapter upon
reading an excellent study in the August 1983 issue
of Scientific American. Three engineers, Petter
Aune, Ronald Sack, and Arne Selberg, surveyed half the
stave churches of Norway (dating back to the tenth century)
to write, “The Stave Churches of Norway.’’
“…it is possible to
build wood structures that will last indefinitely if
certain conditions are satisfied. The wood must be carefully
selected and cured, meticulous design practices must
be applied, attention must be given to details that
forestall decay, construction methods must be of high
quality, and the structure must be maintained continuously
to minimize deterioration. The evidence shows that if
these conditions are met, wood buildings can be permanent.”
These engineers narrowed the reasons
for the longevity of these huge buildings down to five
basic reasons, some of a very specific nature, and others,
of a more general sort:
- Extraordinary care was taken in
the selection and preparation of the wood.
- The buildings were designed to suit
the exposed sites upon which they were located.
- Significant structural innovations
pro-tected the wood from deterioration.
- The structural members were stressed
at an extremely low level — about one tenth
of what they could easily have handled.
- Connections, joinery, and fastenings
were done with accuracy.
Timber builders generally, and log
builders in particular, can easily appreciate the truth
of these statements and identify with them. Granted,
we have often been prevented from employing all of them
owing to strictures of time, budget, availability of
logs, and so forth. It is advantageous for us, however,
to look at these principles and apply them to our work.