Vent stack on metal roof


#1

Because of a slow drain issue our plumber is going to install a new vent through our existing AP panel roof (muellerinc.com/roofing/appanel.php.) Our general contractor wants to put a lead roof jack on top of the metal roof, screwed and puckied in place (NP1 or similar). I think the jack should be under the roof panel so water sheds over the roof jack. Our slope is 2/12 single slope, galvalume panels. I had seen an image of this type of fit but can’t locate it now. Any advice would be welcome.
Thanks.
Tony


#2

There’s gonna be a lot of metal roof repairs to be done in the near future. :smiley:

The lead roof “jack” should be sandwiched between a lower roof panel and an upper roof panel. Preferrably soldered.
Frank aka “tinner666” has some pictures on his website and forums. If he comes around I’m sure he would post them.


#3

Not going to let me just lurk around eh? BTW Dennis, I believe I uploaded another album on your site the other day about channeled valleys.

Her are some pictures that can help. http://rcs.si-sv2628.com/show_album_photo.asp?userid=30&AlbumID=598&file=4434&s=0

Some people swear by those screw down thingies. I’ve never used them. I’ll unlock a seam and add the pipe collar and do it right. (Must cost 4-5 times as much, but it’s bullet-proof, so to speak.


#4

You two artisans make us normal roofers look REALLY bad.


#5

Sandwiching the pipe flashing will create a splice between panels… besides, the spliced panels should overlap… and it’s not going to happen on the existing roof.

Even if you splice it, it is going to be a potential leak with a lot more potential than putting an adjustable rubber flashing for …

http://www.roofing.com/images/topics/7353/img_1235084760.jpg

Seal the above boot with Solar Seal and put good screws in it and you should not have any problems.

Worst case scenario, you would have to re-seal it or change it in 5 or 10 years. Very inexpensive, and unlikely…

If you splice the panel, you’s still have to rely on adhesive… I’m not sure about soldering the Galvalume or g-90 panel, as that in my opinion will destroy the galvanizing coating = rust! Just my 2 cents…

In any case, you should have installed a membrane roof on a 2/12 pitch…


#6

The pitch is really low, so you aren’t going to see it very well. I wouldn’t mind puting a star vent, galvanized. I would Geocel it or NP-1 it and use metal frame screws. The AP panel has exposed fasteners, so whats a few more. I think it will look better than a lead vent that does not have a ridged base.
Especially if this panel has been up for any amount of time. If you tried to match the panel with a new one, It is probably never going to match. I think Muellers galvalume panel has no warranty against oxidation. The plus panel has some, but not on color.


#7

ditto dennis,
but its doughtfull youll get that detailed a repair.
theyll probably cut a hole and seal boot on top of metal.
its common practice.
hopefully it wont leak.

gweedo.


#8

[quote=“tinner666”]Not going to let me just lurk around eh? BTW Dennis, I believe I uploaded another album on your site the other day about channeled valleys.

Her are some pictures that can help. http://rcs.si-sv2628.com/show_album_photo.asp?userid=30&AlbumID=598&file=4434&s=0

Some people swear by those screw down thingies. I’ve never used them. I’ll unlock a seam and add the pipe collar and do it right. (Must cost 4-5 times as much, but it’s bullet-proof, so to speak.[/quote]

What are you using as an underlayment on the roof you have pictured? I didn’t see any red rosin or evidence that you’re using an underlayment. Surely my eyes deceived me.


#9

I’ve never used them. I’ll unlock a seam and add the pipe collar and do it right. (Must cost 4-5 times as much, but it’s bullet-proof, so to speak. luxury home builders az


#10

What would be the purpose of underlay? No resin paper was needed since the planks were already 100 years in age.


#11

who puts metal on a 2/12? I hope you have a high temperature ice and water shield under that. I would tear it off and apply a low slope product tpo, pvc, epdm, flintlactic, torchdown or even hot tar but no metal on a 2/12. I don’t know where you guys do metal but check your manufacturors specs.


#12

You sound like you know your roofing.

I have got a low slope roof coming up.
I was going to use either flintlactic or torch down.
Which one would you use?


#13

flintlastic makes torchdown.

gweedo.


#14

[quote=“gweedo”]flintlastic makes torchdown.

gweedo.[/quote]

I think he is speaking of their sa product


#15

cetainteed makes flintlastic wich is a peel and stick product similar to ice and water, they also make torchdown wich is applied with a torch. Both have a 5 year warranty. Malarkey also makes good low slop products. I would use versico epdm at least 45 mill reinforced fully adhered with a 20 year warranty available. It should be close to cost easier and safer than torchdown. Carslile makes versico and all accessories interchange but you don’t have to pay for the Carslile name. epdm is its own animal don’t use if other roofing products especially asphalt are used on the same roof slope.


#16

[quote=“roof-lover”]

You sound like you know your roofing.

I have got a low slope roof coming up.
I was going to use either flintlactic or torch down.
Which one would you use?[/quote]

Ok, i admit i was kidding.
I disagreed and went about it the wrong way.
I do think certain metal systems are acceptable on a 2/12.

GNFR, could you please elaborate why you think metal is unacceptable on a 2/12 without ice/water?


#17

Hello,

I just attended an AEP-SPAN seminar this past Thursday. They warranty their Klip-Rib panels to a 1 in 12 pitch and their Span-Lok and Span Seam panels to a 1/4 in 12 pitch. As far as checking the manufactures specs, the man who gave the seminar is the man who does the inspecting for the whole northern states and Alaska.
We roll our own panels and are UL rated so we warranty our work to whatever the pitch is.

Keith


#18

I have got a low slope roof coming up. Custom Floor Plans


#19

[quote=“twright”]Because of a slow drain issue our plumber is going to install a new vent through our existing AP panel roof (muellerinc.com/roofing/appanel.php.) Our general contractor wants to put a lead roof jack on top of the metal roof, screwed and puckied in place (NP1 or similar). I think the jack should be under the roof panel so water sheds over the roof jack. Our slope is 2/12 single slope, galvalume panels. I had seen an image of this type of fit but can’t locate it now. Any advice would be welcome.
Thanks.
Tony[/quote]

I’m not being mean but, when you were getting estimates for a metal roof, didn’t anyone suggest standing seam? Did you wonder if the screws would leak one day? I would use the poly boot someone else recommended. Thats what they are made for. I’m not a big fan of np-1 (for metal) because it doesn’t bond to kynar. I don’t know about simulated polyester finish I haven’t tried. Standing seam will work on 2:12.