WHY DID MY HOUSE BURN DOWN
( WHILE MY NEIGHBORS DID NOT)?
This question came up many times in the aftermath of both the Thomas Fire (2017) and the Woolsey Fire (2018); the answer is the same for both: wind driven embers. And it just happened again in the recent fire here in southern California..... what made your neighbor's house less apt to burn down when yours did? 1. Age of the house: Older homes were built differently, to less stringent building codes and with lesser quality buiding materials not intended to ward off the flying embers and ground level onslaught of flames. 2. Attic ventilation: conventional wood framed sloping roofs more often than not have roof eave vent openings to allow air flow in your attic. Wind driven embers find their way into these vent openings and, while still glowing red hot, land upon combustibles and start a fire within the house itself. While the exterior wall and roof surfaces may be able to ward off these embers, the attic is a vulnerable target.
Next post will have some graphics to delineate the differences how the newer, fire resistant code materials and methods prevent this invasion of the wind driven embers......