Adding downspout to torchdown roof

I have a torchdown roof with built-in gutters. One side of the roof only has one downspout in the middle, and water is pooling up at the ends of the gutter instead of draining into the middle. I’d like to add downspouts at both ends, but I’m not sure how to do that. Can I just cut through the membrane, drill a hole in the sheathing and add some sort of scupper to attach the downspout to? Thanks in advance…


Sounds like you are describing adding a drain as opposed to a down spout.
Photos would be helpful.

call a licensed,insured roofing contractor!!!

Yes, photos.

Here are some photos:

You need a real roofer to fix that properly, it just ain’t right…
Looks to me like he deck needs to be fixed, that low spot needs to just go away.
From the pics it looks like it can be made to drain off of the overhang, eliminating the need for the drains and associated plumbing.
It just wasn’t designed right in the first place and needs to be fixed.
This isn’t a DIY project…

One that knows about flat roofs and how to deal with them.

Part of your problem is in how the drain was set into the roof. It really should be something like a T where the top of the T overlaps the topmost part of the roof area.

Like this:

Obviously, there is more to it than the image I posted, but if you look @ the last pic of yours, you can clearly see through the side & the layers are visible. That’s part of your problem right there; water has access through the strata.

Thanks for the replies. I wanted to get some feedback on the amount of ponding in the pictures. The pics were taken in the afternoon after it had rained most of the night and day before. Does this seem like it’s excessive or is it not that bad, particularly since it is over a cantilevered area?

Ranchhand, is the setup you describe something I could add over the top of the existing roofing? Is there a ready-made part that I could use to do this?

My other thought was to add an external gutter, but I’m not sure what modifications that would require with this type of roof. Any thoughts?

An external gutter would mean you need to totally remove the lip that’s holding the water in. Are you ready for this kind of work or expense?

I am not sure on what option you might need for the repair on the pipe through-roof.

One big problem is people who do a retrofit only slap bull on the top of the joint; that’s not where it is needed; you place it in between the flat top & the roof to promote a seal there, not on top @ the joint.

I agree that it’s not something you can do well yourself. Call a pro.

install a drain sleeve and 3-course it and your other drain hole