Almost a dozen fire engines responded to a house fire on Jay Street in Los Altos yesterday (July 4) after varnish-soaked rags ignited a blaze.
No one was injured in the fire, according to resident Sam Lodestro, and although smoke damaged the entire home only a garage and toolshed were destroyed.
Lodestro said that the remnants of a fence-finishing project started the fire, which was reported by a neighbor who saw flames.
Santa Clara County fire investigator Dennis Johnsen said at the scene that the day's extreme hot weather required a two-alarm response so that firefighters could alternate, taking off equipment and cooling their core temperatures in a shelter set up down the street.
By approximately 4 p.m., firefighters were still working on the damaged garage but the area was safe for the homeowners to approach. The fire had caused the house's electrical line to drop and was initially "dancing around quite a bit, arcing," Johnsen said.
Johnsen said that varnishes and stains present a risk of spontaneous combustion when applied to cloth rags, and that the department had seen a similar case the day before, when somebody was staining a deck.
"We see maybe ten of these every summer," he said.
Rags soaked with varnish or lacquer must be hung or spread out to dry in a safe place. Evaporating chemicals create heat that can combust when rags are folded or piled.