Need Definition for Basic Roof Flashing Terms

[John Ross]

I am confused as to the terms "sheet metal jacks" and "collars" used in roofing flashing for vent pipes.

Can these be one unit?

Here's what I see: What looks like a "cone" attaced to the bottom of flat flashing. So this piece is put over vent pipe and thus you have a metal "bottom" and a "cone" that comes up a little ways on the pipe, then the rest of the pipe protruding upwards.

So is the bottom part the "jack" and the "cone" the collar? What confuses me is it looks preassembled to be one unit, but are the two "parts" labeled differently or does this one unit have a name? Or are these interchangeable terms?

Thanks. And before making fun of my newbieness, at least I didn't ask what a vent cap was! :)

[Colbyt]

I am not familiar with the terms as you expressed them.

The ones used for plumbing pipes are normally one piece. Ditto that for electrical masts.

It is normal for the ones used for gas vents and metal chimneys to be in two pieces. You have the base portion which includes the part that surrounds the pipe. These I have heard called jacks. and then there is a storm collar which fits tighter to the pipe and tops off the jack.

The theory being that the jack must sometimes be trimmed based on the pitch of the roof. The storm collar is always parallel to the ground and is never trimmed.

[marson]

these terms vary a lot in different areas, i think. i would call the sheet metal jack the flat piece with the cone shaped flashing. the flat piece attaches to the roof (and is tucked under the shingles) and the cone shaped piece goes around the pipe. the only collar i know of is a "storm collar" which attaches to the pipe above the flashing. (used on metal chimneys). this is caulked to the pipe, and prevent water from going down the pipe. you can't caulk the flashing directly because movement would break it.