flashing detail: missing something?

Just looked at a friend’s new roof in progress: it’s a panelized metal roof , pcs. about 16″x24″ +/- and look a little like shake shingles………coated with a fine, colored aggregate. ( Don’t know brand) The pieces rest on horizontal 1×2 battens, and are nailed on bottom edge’s vertical detail so that water will run past nail heads. So far, so good. 50 year warranty claimed……..My question concerns the flashing around the vents; As seen, the roof jacks are buried under particular course of panel completely. This doesn’t seem right, as I expect to see the bottom of the roof jack emerge downhill to shed water. Installer indicated that special compound will fill in the gap between . I feel like a little expansion/contraction, and this will fail, leading to water infiltrating the underside of the panels……anyone worked with this stuff?
What about neoprene boot-type jacks? or some kind of counter flashing? Appreciate some insight .
Replies
Typically, Lila, In a detail like this, the roofer would have been supplied with some coil stock in the same or similar material as the metal shingles for custom fabrications, such as extending the base of the flashing to lap on top of the next lower course of shingles. If he is depending solely on caulking, the seal will fail well before the roof material does and become a source of regular and repititious troubles.
Excellence is its own reward!
piffin, thx for your posting a couple of days ago; the method you said the manufacturer would likely lay out , that is, custom flashing using matching roof stock, IS what was hiding under the roof jack and a piece of roofing---the down leg of the course that is peirced by the vent hides this detail. (a 90 degree downleg that is the nailing flange , too.) This 90 deg. is pretty tight to the matching feature of the lower course, and tight to the flashing extension. Sure hope the water that gets behind there can get to daylight--the extension is lightly corrugated so that will help...........am thinking a little freezing and water will back up. But the workmanship seems to be the best that the product will allow. I'd dream up some kind of 'cora-vent' device that would give more drainage area but allow cosmetic covering of the lower portion of roof jack.
Anyway, I was just a looky-loo on the project.
p.s. it's Lil' Acorn, not Lila...............does piffin stand for prodigious postings, or is it from Harry Potter? ( not important, no answer necessary.)
LOL
Lila Corn sounds more intriguing...
Piffin is a phonetic pronunciation of my initials, PFN
I'm not into HPotter. Is there a piffin in it?.
Excellence is its own reward!
This sounds to me like a Decra roof or at least a similar grid work and shingle size. We got to watch a company-trained crew apply one of these on a large house last summer. As a matter of fact, it was on our main client's home and was at my suggestion as the shape of these shingles mimics a tile roof. Very nice look without having to build up the super-structure for the weight of tile. They edge-screwed all of the roofing down rather than nailing.
We witnessed the same sort of detailing (or the lack of it) on this roof. Needless to say, we questioned them about some of their techniques and were told the same thing concerning the caulk and the color matched granules that get imbedded in it to match the roof. Well, it turns out that they were using a polyurethane caulk and relying upon that to seal the joints forever.
.
I dunno. I saw a lot of stuff go on up there on that roof that I really didn't like to see. This is on a brick home with several large brick chimneys and no attempt was made to flash and counterflash those chimneys in a traditional fashion. Instead, all color matched flashings were simply applied against the brick with a bead of poly-caulk squished in between as the flashings were screwed down with tap cons. Same procedure wherever a roof met a wall.
The one that really got my goat was where they flashed up against the only bevel-sided dormer around the back of the house and they ran the flashing right up against the outside of it. I'm sure you can visualize just what kind of water-collecting pockets this created. No attempt was made to fill these pockets, but rather they just left them that way!! Well, not for long. We climbed up there and filled them with poly-caulk once they declared they were done and had left.
I saw the same flashing stuff going on around their vent stacks that you describe. Water-shedding is totally dependent upon the lasting integrity of the caulking. At least on this home, the Decra roof was applied over a yet good layer of asphalt shingle.
They did do a nice job of flashing the valleys and a several eye-brow dormers. I was up and down the ladder numerous times to check out their work in these areas.
I suspect that pricing is the reason for the lack of what I would call proper flashing installations.
Great lookin' roof with a fifty year warranty, but I'd intend to check in on that caulking periodically if it was on my house.
Hey Goldhiller, you've described pretty much the type of product I saw on that roof--and it DOES look nice from the ground......this one replaced real cedar shakes and the textured panels gave it a look that spoke to that. To this crew's credit, they didn't slap the flashing on top of the beveled siding, they took the trouble to cut a larger relief on the siding and slide some L-flash in there. But the metal chimneys and round vents got that might-need-caulk-to last treatment.
Lil' Acorn
This sounds to me like a Decra roof or at least a similar grid work and shingle size. We got to watch a company-trained crew apply one of these on a large house last summer. As a matter of fact, it was on our main client's home and was at my suggestion as the shape of these shingles mimics a tile roof. Very nice look without having to build up the super-structure for the weight of tile. They edge-screwed all of the roofing down rather than nailing.
We witnessed the same sort of detailing (or the lack of it) on this roof. Needless to say, we questioned them about some of their techniques and were told the same thing concerning the caulk and the color matched granules that get imbedded in it to match the roof. Well, it turns out that they were using a polyurethane caulk and relying upon that to seal the joints forever.
.
I dunno. I saw a lot of stuff go on up there on that roof that I really didn't like to see. This is on a brick home with several large brick chimneys and no attempt was made to flash and counterflash those chimneys in a traditional fashion. Instead, all color matched flashings were simply applied against the brick with a bead of poly-caulk squished in between as the flashings were screwed down with tap cons. Same procedure wherever a roof met a wall.
The one that really got my goat was where they flashed up against the only bevel-sided dormer around the back of the house and they ran the flashing right up against the outside of it. I'm sure you can visualize just what kind of water-collecting pockets this created. No attempt was made to fill these pockets, but rather they just left them that way!! Well, not for long. We climbed up there and filled them with poly-caulk once they declared they were done and had left.
I saw the same flashing stuff going on around their vent stacks that you describe. Water-shedding is totally dependent upon the lasting integrity of the caulking. At least on this home, the Decra roof was applied over a yet good layer of asphalt shingle.
They did do a nice job of flashing the valleys and a several eye-brow dormers. I was up and down the ladder numerous times to check out their work in these areas.
I suspect that pricing is the reason for the lack of what I would call proper flashing installations.
Great lookin' roof with a fifty year warranty, but I'd intend to check in on that caulking periodically if it was on my house.