Deeper charring may accompany high ventilation areas. Char Appearance Little can be said about the significance of char's appearance with respect to a fire's intensity or rate of burning. The cross-section of char however, can yield some information about the intensity of a fire. A slowly developing fire will produce a more gradual formation of char. Gas Fuels Fugitive fuel gases can provide some limited information about the origin of the leak.
Fugitive gasses provide even depths of char over wide areas.
Changes in char depth can lead to locations of pocketed gasses, and the deepest charring may exist close to point of leakage.