Roof Penetration

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rookie4now

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We need a single vertical penetration as shown in the photo. Someone has already penetrated the sheet metal cover as shown for the CATV. Is there any problem with coming out on the opposite of the hood with 3/4 EMT and then 90 degree bend? there Doesn't seem to be enough room for a jack, so we could wrap the conduit with foil and caulk it with gutter caulk or similar.

the other option could be to come out on a 90 through the side of the curb.

Any thoughts?
 
There are devices manufactured for just this purpose, they have all kinds of names such as "top hats", "witchs hats", etc...

I have never heard of or seen "wrap the conduit with foil and caulk it with gutter caulk" as a method...seems that would eventually leak.
 
roofing tar works pretty well at sealing holes. if you use a witches hat like pierre said make sure you use tons of silicone and screw it down every inch :) i never had one leak yet
 
Pierre C Belarge said:
There are devices manufactured for just this purpose, they have all kinds of names such as "top hats", "witchs hats", etc....
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What's the difference between a witches hat and a roof jack as mentioned in my original post? I've never heard the term, but a regular roof jack looks like a witches hat. Are they the same thing?
 
rookie4now said:
We need a single vertical penetration as shown in the photo. Someone has already penetrated the sheet metal cover as shown for the CATV. Is there any problem with coming out on the opposite of the hood with 3/4 EMT and then 90 degree bend? there Doesn't seem to be enough room for a jack, so we could wrap the conduit with foil and caulk it with gutter caulk or similar.

the other option could be to come out on a 90 through the side of the curb.

Any thoughts?
Click to expand...

That sort of looks like a weatherhead.....am I crazy?
 
There are devices manufactured for just this purpose, they have all kinds of names such as "top hats", "witchs hats", etc...
Click to expand...

I call them 'Madonna Cones'.

Make sure the clamps you use are SS and not just something someone grabbed from an auto parts store, though. Some clamps have SS straps and regular steel for the screw.
 
rookie4now said:
What's the difference between a witches hat and a roof jack as mentioned in my original post? I've never heard the term, but a regular roof jack looks like a witches hat. Are they the same thing?
Click to expand...

I have never heard the term 'roof jack' to be used to describe this device but Google led me to a site that had them, they are a form of flashing and are not flexible, per se, nor are they cone shaped.

Pitched_RJ.gif


My preference would be the cones.
 
Do you have to come out of the sheet metal cover? Would be easier if you could just penetrate somewhere where the roof is flat and put a "hat" down.
 
Coming out of the curb that is already installed will minimize the exposure to water, so it's not a bad idea. If you cut the hole tight and seal it properly you wan't have any issues.

It's always best to pick a high point when penetrating a flat roof. I aim for the crickets or existing curbs if at all possible.

Out here we call the flashing components 'roof jacks'.
 
Just a heads up, many flat roofs have very long term warranties and if penetrations are not made correctly that can become a major issue for the roof owner / your customer.

We did a solar install on a Firestone roof product and had over 200 mounts that had to penetrate the membrane. The mounts where shorter then any 'witches hat' that Firestone accepted. The roofing contractor had to have custom ones designed then approved by Firestone and then manufactured. Had we not done this Firestone would not honer the roofing warranty.

Do what you want with that info. :smile:
 
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