posted 11 years ago
Cen rees : There are 2 Conditions of wood failure that reduce the integrity of wooden members that result in a loss of mass, structural strength, and increased fire
danger, especially in 'Hidden locations' with poor air circulation, like inside walls, and under floor boards, especially in crawl-spaces !
1 ) -Sometimes called low temperature pyrolysis, This most often occurs to floor joists and rafters too close to Un-insulated, high temperature exhaust stream heated
stove pipe ! Slowly the wood out-gases, Usually never reaching a high enough concentration of flammable gasses to allow Combustion, the Lower Explosive Limit, or
L.E.L.. Eventually the wood has outgassed enough volatiles to render the remaining wood to a state very similar to deeply Charred wood. Most of its structural integrity
Is lost ,and the wooden member is now as flammable as an equivalent sized and shaped piece of Charcoal ! Often this can take decades, but it is frequently observed
to 'be a work in progress' in older homes !
2 )- So called dry rot, sometimes combined with insect damage, resulting in a tinder-dry condition with little structural strength and increased fire danger !
More mass,or even layers of insulative batting material is not as protective of your houses environmental envelope as a properly placed Radiant Heat Barrier and the
use of air Gap(s) ! Properly constructed, you are also improving the safe convection of air through the channels you have created between the wooden floor/walls and
the bottoms of your elevated pavers !
Again, these gaps and the protection they add promote your structural integrity and felicitate long term, whole house longevity !
For the Future/Good of the Craft ! Be safe, keep warm ! As always, your comments, and questions are solicited an are Welcome ! PYRO - LOGICALLY Big AL !
Success has a Thousand Fathers , Failure is an Orphan
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