Smoke Webs (Soot Tags)
Smoke webs, also called soot tags, are spiderweb-like chains of soot that form in corners and on ceilings during a fire, produced when smoke particles cling together in cooler, less-ventilated areas.
What Smoke Webs Are
Smoke webs, known in the trade as soot tags, are stringy, cobweb-like deposits of soot that appear in the corners of rooms and where walls meet ceilings after a fire. Despite the name and appearance, they are not spider webs; they are chains of soot particles that have bonded together and collected in specific spots.
They form because of how smoke moves through a burning structure. Synthetic materials burning at lower temperatures produce charged soot particles that attract one another, and they accumulate where airflow is weakest and surfaces are coolest, typically in corners and other protected areas. Their presence is a clue to the type of materials that burned.
Why They Matter During Cleanup
Smoke webs signal that a fire involved plastics and synthetics, which tend to leave sticky, smeary residue that is harder to clean than the dry soot of a paper or wood fire. Encountering heavy soot tags tells technicians to expect an oily film throughout the space and to plan their cleaning methods accordingly.
Like other soot, smoke webs should not be wiped casually, because doing so can smear the residue and stain the surface. They are removed as part of the structured soot-cleaning process, generally starting with dry methods such as HEPA vacuuming and chemical sponges. Work often proceeds under containment with HEPA filtration so airborne particles are captured rather than redistributed.
Telling Soot Tags From Ordinary Cobwebs
One of the first things a technician confirms is whether a stringy deposit in a corner is a genuine soot tag or an actual cobweb that has simply collected airborne soot. The distinction guides how the surrounding area is assessed. True smoke webs are chains of bonded soot particles, so they are uniformly dark through their whole thickness, greasy or brittle to the touch depending on the residue, and concentrated where airflow was weakest during the fire, the upper corners of rooms, along crown molding, and behind doors.
A pre-existing cobweb, by contrast, is a spider's silk that merely caught passing soot; it tends to be lighter, more elastic, and anchored differently. Recognizing heavy soot-tag formation also helps a restorer read the fire itself, since dense tags point to synthetic, low-temperature combustion and warn that an oily smoke film likely coats surfaces well beyond the visible deposits.