A house fire on the city's northeast side on Monday was blamed on a fire lit in the fireplace during this chilly weather, leading Tony Darrah to warn homeowners not to light that first fire of the year before you have gotten your chimney scrubbed.


  Darrah, who runs Texas Chimney and Wildlife, says soot build up in chimneys is the single most common cause of house fires around the first cold snap of the winter.


  "Creosote will build up in the flue pipes," he says.  "The initial sound is like a jet engine, and it will start shooting fire out of the top of your chimney."


  In addition, birds and other animals may have built nests in the chimney flue over the hot summer, and they could add to the misery as the twigs and other nesting items they use are very combustible.


  The sparks and flames shoot out of the chimney vent and frequently set the roof on fire.


   "It's not just one of those things where you say, oh, well, the garage is dirty, I guess one of these days I need to clean it'," he said.  "This is a life hazard, if you don't clean if you are going to use it."


  He says if a family uses a fireplace regularly, the chimney should be cleaned once a year.