What may look like grime and cobwebs in this photo is actually soot from a furnace puffback. Puffbacks occur when the unburned excess oils of improperly maintained or old furnaces suddenly ignite, sending smoke out of every heating vent its connected to. This unexpected furnace explosion typically leads to every room in a given building being coated in dangerous, unhealthy amounts of soot. If something like this happens to you, call the fire restoration experts at SERVPRO of Mid-Outer Cape Cod the remediate the situation, 24 hours a day and 7 days a week. From Mashpee to Provincetown, we're on alert to fix most any puffback-related mess