What Is a Pipe Boot?

The base is a flat flange shingled in like other roof flashing, tucked beneath the upper courses and resting over the lower ones, and a collar rises from the center to grip the pipe. Most are a flexible rubber or neoprene collar bonded to an aluminum, galvanized, or plastic base. Others use lead or an all-metal design with a gasket. The collar is the weak point. Sun and weather crack it long before the shingles are worn out, which is why a roof can look fine and still leak at a vent pipe.

A split collar is among the most common causes of small leaks, so a careful inspector checks every pipe. Finding one on an otherwise sound roof also proves the visit was a real inspection. On claims, though, a deteriorated rubber collar is wear, not storm damage, and an adjuster will say so. Blaming hail for a cracked boot hands the carrier a reason to doubt everything else in the file.

A pipe boot fits a plumbing vent. Furnace and water-heater flues use different metal jacks with storm collars, and bath fan and range vents have their own flashings, so the term is not a catch-all for every round penetration. Quick fixes exist, such as slip-over repair collars and sealant, but they are repairs. On a replacement, every boot should be new, since a fresh roof with an old collar leaks at its oldest part.