Roof jacks over or under lower courses?
Okay, we finish the roof this weekend. Have one plumbing vent and one 4″ wall heater vent to deal with. Getting conflicting advise about whether to seal the jack and flashing directly to the deck or underlayment, whether to put them above the bottom courses and below the top courses, and whether or not to use sealant if we do go between the courses.
Looked at a lot of new roofs and although the majority have visible flashing below the stacks, quite a few are shingled all around.
The attic is well ventilated (now) so several feet of snow may sit up there for a while.
My plan is to put the flashing above the bottom courses and to use sealant (a lot of sealant at the top of the bottom shingle), and nail the top only with conventional roofing nails. Am I on track or way off base?
– Curtis
Replies
The instances where the bottom of the flashing is covered may be shingle overs. Common sense dictates that the flashing would overlap the course below, rather than underlap (is that a word?), relying on caulk or cement when none is necessary.
gl
I went to a bookstore and asked the saleswoman, "Where's the self-help section?" She said if she told me, it would defeat the purpose.
You've got it right. Just keep the laps facing downhill and the water can't get in.
Sometimes the stack falls in just the right place in the shingle layout so that the top of the first shingle cuts around it then the jack flashing goes down over it, then the next shingle can totally cover it for looks, and the third shingle caps over all.
Othe4r times some jack flashing shows.