Q: How is the flashing size determined?
A: The size of the flashing is determined by the OD (outside diameter) of the pipe penetrating the roof or
sidewall of home or building. Never try to slide a smaller flashing collar over a larger pipe because it will
cause fatigue failure in the collar. Never install a larger collar over a smaller pipe and try to use sealant to
fill the void. Any sizing miscalculations will lead to leaks within the home or building.
Q: How is a rain collar installed?
A: After the correctly sized collar has been selected; you will apply a 100% exterior or marine-rated silicone
caulk to the top of the existing rain collar attached to the roof flashing, and also to the underside of the
new rain collar. Slide the new rain collar down over the pipe to the top of the existing collar. Press the new
collar down with enough pressure to seal the two together without collapsing the seal around the pipe.
Q: Is there a roof flashing for corrugated (engineered) roofs?
A: Yes. The Oatey Master Flash and Retro-Master Flash are designed to conform to most roof profiles.
Q: What is the manufacture warranty for flashings?
A: With the exception of the Master Flash and Retro-Master Flash, all flashings have a one year warranty
from the date of manufacture. Flashings cannot be guaranteed for the life of the roof due to varying roof
life spans, and potential adverse conditions (i.e. extreme heat, extreme cold, hail). If a roof is replaced, the
flashing should be replaced at the same time. Master Flash and Retro-Master Flash are the only exceptions;
if installed properly according to industry standards, they have a 20 year warranty from date of manufacture.
Q: What flashing is used for single wall metal exhaust pipes attached to water heaters and furnaces?
A: Single wall metal exhaust pipe should never be used to vent a water heater or furnace when the pipe
passes through a combustible material of any kind due to risk of fire. The flashing rain collar will melt or
warp if exposed to these temperatures passing through the single wall pipe, and loose the water tight
seal it is designed for. All water heaters and furnaces not listed as high efficient should be vented using
rated B vent pipe. B vent pipe is doubled wall pipe which isolates most of the exhaust heat to the interior
pipe. All Oatey flashings are safe to use with B rated vent piping.