Questions About Flashing Where Roof Abuts Walls

Chunkstyle

hi guys

i'm going to be doing a reroof soon, (tearing-off first, per grumpy's advice) and was wondering if any of you could offer any advice on doing the flashing at areas where the roof abuts a wall on the side that's vinyl-sided and areas where the top edge of the roof abuts a wall, with the same siding.

i've looked thru a bunch of roofing books, and it seems like 1'-0 pcs of step flashing is the way to go on the sides. one book seemed to indicate putting the step flashing in bit by bit as you run the shingles up, each piece lapping over the shingle under it (as opposed to doing all the flashing at once then shingling over it), for a "woven" effect. another book showed counterflashing on top of the shingles as well, although in looking at roofs in my area with similar wall abutments, i haven't seen any using counterflashing (on the sides, i mean -- the top wall abutments do generally seem to use counterflashing on the roofs i've looked at lately).

also, the books all kinda gloss over how you actually get the vertical leg of the flashing up under the existing siding. they mention stuff like "loosening the siding a bit" or "notching the flashing around nail shanks", but in practice, it seems like it's going to be a serious bitc* to do. my siding has j-channel along the bottom edge at the roof, so i know there's going to be a row of nails right at the bottom edge, and i'd hate to have to take the siding completely off (especially since starting at the bottom, i'd have to take off probably 4' of it vertically to account for the roof's rise by the time i get to the peak).

i figure the flashing's got to have a 3" or 4" vertical leg to do its job, and i just don't know how i'm gonna get a leg that length up under the siding without tearing everything up, or without bending the flashing so badly while stuffing it up in that the crease made while forming it is destroyed.

the situation at the top-end wall abutment is similar, although i'd only have to remove 1 couse of siding.

any comments about this?

help, please!

thank you!

Kevin

Step flashing works well...and it needs to be under that siding.

The bottom J on that vinyl is likely only nailed into the studs, so you'll only encounter a nail every 16" or so.

Worst case scenario, you pull the vinyl. If it isn't very old (brittle) it should not be a big job.

Sounds like you're really doing your research!

Grumpy

Step flash AKA Baby tins at the side wall. Apron flashing ( you will need a metal break) at the top wall. Vinyl siding is nice because it is forgiveable... Also try to always slide your flashing under the tyvek (or similiar underlayment) behind the siding. This is called counter flashing, so any water that gets behidn the siding, and it will, will not be funneled into the roof.

Definetlyt install your baby tins piece by piece.

AaronB.

I concur with G money.

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