[Homestead] Responses to preserving poles in the ground

Don Bowen KI6DIU don.bowen at earthlink.net
Thu Nov 1 14:22:31 EST 2007


Here is what most of the responses have told me along with some 
research.  These ideas are based on using timber from the site.  If 
purchased timber is used, just buy the latest PT stuff and be sure to seal 
it off.  Forgive the cross posting but I did get answerers from many sources.

Setting a pole for building is easy.  It just depends on your climate, 
frost line, wood species, load, personal preferences. etc.  The problem is 
moisture, when wood gets wet the microbes already there and waiting start 
to munching.  Exposed exterior wood is food for another army of hungry 
microbes and insects.  In some areas the hungry beasties are so busy and 
take no vacations that there is no real cure.  No matter what is tried, in 
the tropical island of Saipan wood in the ground lasts no more than five 
years.  Cars have a hard time lasting 10 years before they rust away.

Drainage is the very first line of defense.  Make sure that any water 
drains away from the poles and none can settle around the pole.  Choose 
your house site and grading so all water moves away or is channeled 
around.  Wide eves keep water from splashing and running down the sides.

In the hole use rocks or gravel to insure drainage of any moisture that 
does get in the hole.  Set the post holes well below frost level then pour 
in several inches of coarse river rock.  Set the pole and pour in some more 
rock, leaving a few inches at the top for a collar.  Mound the dirt at the 
top or pour a collar of concrete with a peak to drain water away.  Heavy 
tar treatments and wrapping in plastic may just make a better trap for 
surface moisture.  In loose soils it may be advantages to pour a collar of 
concrete about half way up the hole.

As for the pole, species if very important.  Locust and Ceder are often 
mentioned as long lasting poles.  From personal experience Locust fence 
posts out last just about everything but Osage Orange but are much 
straighter.  Chemical treatments, used motor oil, and tar were frequently 
mentioned.  Charing the pole was also mentioned several times.  Be sure the 
pole is completely air dried before use so any checks can be delt 
with.  One idea was to bore a hole in the base to speed drying, reduce 
checks, and allow penetration of what ever preservative used.

If the ground does not drain well, don't bother with poles set in the 
ground but use a form and make a cast in place concrete pier.  They can be 
stopped at grade and steel anchors used to secure the poles.


Don Bowen              Awl Knotted Up                       KI6DIU
http://www.braingarage.com


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