UNDERGROUND OAKS
Mother staff experts answer questions on building an in-ground, passive solar home and the pollution dangers of formaldehyde.
 |
Great care must be taken in using logs in an earth-sheltered dwelling.
|
ASK OUR EXPERTS
RELATED CONTENT
Buying or building a small home is a great way to significantly reduce your energy use, and you don...
There are thousands upon thousands of abandoned farmhouses scattered throughout the U.S., at bargai...
I'm renting an old Finnish homestead near Nolalu, Ontario....
A community canning center is the answer....
Hi-Ho, Come to the Fair July/August 1982 Only a "simple Simon" would willingly pass up a chance to ...
Home-built walls, home-brewed pollution
I'm planning to build an in-ground, passive
solar home in southwestern Wisconsin. My question: Can I
successfully use oak logs for the main structure? Could
they be properly water-proofed before backfilling? I know
that the usual material is concrete block, but I have 60
acres of white oaks in desperate need of thinning. Right
now they're just being cut for firewood.
It's no doubt possible to use white oak logs in an
earth-sheltered house. My question: Do you really want to?
Will the effort and cost be acceptable? Assuming you want a
house that will still be around half a century from now,
here are a few of the things you should worry about.
1. Structure. You must find a way to
secure the logs to the footings to resist sliding forces.
This could be done by setting threaded rod in the footings,
slipping the bottom course over the rods and snugging the
log to the footing with nuts. Each subsequent course should
be secured to at least the previous two with pins at the
joints, and staggered at several locations between joints.
Traditional log corners may not offer enough resistance to
over-tipping forces unless they are heavily reinforced (by
steel rod passing from top to bottom and into the footing,
and possibly by a bond beam) and buttressed (by right-angle
walls that are secured to the footing and pinned). The
sizes and spacing of reinforcing elements will depend on
the height of the walls, the soil type and the length of
unbuttressed walls. This is a job for an engineer.
2. Waterproofing. An irregular surface
with gaps—the typical outside profile of a log
building—would place undue demands on a waterproofing
membrane. It's unlikely that any manufacturer would
recommend use of its product unless the logs are square on
three sides to present a smooth, uninterrupted exterior
surface. As an alternative, it might be possible to fill
the gaps between the logs with chinking, affix insulating
panels over this more or less even surface and then apply
the waterproofing membrane.
3. Rot resistance. Even if the
waterproofing system keeps outside moisture out, there's
likely to be some condensation inside. It would be a good
idea to apply a preservative to the logs before installing
them.
Personally, if someone dropped a couple
of semi-truck-loads of white oak logs in my yard, I'd build
an aboveground house or heat my concrete earth-sheltered
house for several generations.
—David Schoonmaker
David Schoonmaker is a senior research editor forMOTHER.
