Which replacement vent pipe boot should you buy?
Short answer. Buy a boot that matches the pipe's outside size, usually 1.5, 2, 3 or 4 inches, with a base flange large enough to tuck well under the shingles. For longer life, choose a boot with a metal base and a UV resistant collar, such as silicone or a heavy EPDM, or a lead boot with a cap; avoid the thinnest all plastic boots, which crack early in Georgia sun.
Measure first
Measure the pipe's outside diameter or circumference. A 1.5 inch plastic drain pipe and a 2 inch one look similar from the ground. Some boots fit a range of sizes with cut off rings; those work when cut cleanly at the right ring.
Collar materials
- Neoprene or EPDM rubber: the most common. Inexpensive, but the collar dries and cracks with sun exposure, often before the shingles wear out.
- Silicone: more resistant to UV and heat, generally a longer life.
- Lead: molds around the pipe and lasts, but squirrels chew it. Pair it with a cap if animals are active.
Base materials
- Galvanized steel or aluminum: stiff, lies flat and holds up to foot traffic.
- Plastic: cheaper, but can crack in hail and grow brittle.
Special cases
- Metal flue pipes: water heater and furnace flues are not plumbing vents. They need flashing made for them, with clearances to combustibles and a storm collar.
- Metal roofs: use flexible boots made to conform to panel ribs.
- Repair sleeves: a rubber sleeve that slides over a cracked collar buys time but does not fix a failing flange.
Install it right
The best boot still leaks if the lower flange is tucked under shingles or nails are left exposed. See pipe boot leaks and metal roofing in Georgia.