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WOOD - Termite Damage Condition Survey

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Charlie Canitz:

Termites, the insidious pests that they are, sometimes (frequently) leave
very little surface evidence of their damage.  During a structural
inspection of the attic space of a shopping center with 5' to 6' deep wood
trusses at 10' on center spanning 60', something about a bottom chord
looked unusual, so I pulled out my pocket knife to probe the chord and it
went clear thru!

There is no way that I know of that an engineer can, with any degree of
assurance, say whether termite damage exists or doesn't exist.  I inspect
for termite damage using a screwdriver, however, termite damage more than
1/2 inch below the surface is usually undetectable by this method.  Also,
termites can often bore a narrow tube in a growth ring and go for a
considerable distance before doing general damage.  
I make these things clear in my agreement:

1.      My report applies to only those areas probed, and termite damage
may exist in areas not probed.

2.      Termite damage more than 1/2" below the surface may go undetected.

3.      Termite tubes may exist in growth rings that were not probed, even
if the general area was probed.

When termite damage is located by probing, there is a distinctive "crunch"
that is unmistakable.

Height should not be a factor in discontinuing inspection for termite
damage.  The bottom chord of the shopping center trusses mentioned was 11'
above the floor slab.  A residence that I inspected had considerable damage
in a ridge beam more than 14' above the floor slab.

If a person *really* wants an inspection for termites, then I require that
*all* walls be opened up for a distance of 2' above the floor and below the
ceiling, and the ceiling be opened up for 2' around the perimeter of all
rooms.  (I have yet to have anyone *really* want that rigorous of an
inspection.)

A. Roger Turk, P.E.(Structural)
Tucson, Arizona