Very old scupper drain system presents unique replacment challenge-PICS
I own a 110 YO Victorian in San Francisco. Here we have a combined storm and sewer drain system.
I have a back porch of about 200 ft^2 ~ 1:4 pitch. This has never had a gutter/drain system. It wasn't a problem, until my neighbors built the stairs to their front entrance within 3" of the rear wall of the porch. They filed a complaint and now I have to install a gutter system. In and of itself, that's not too difficult.
But the area of the main roof (~750 ft^2) drains through a scupper system into what I'd call a "wall sconce" drain laid right against the rear wall of the house. The drain pipe goes through thru the back porch and into the wetwall which also carries kitchen sink and laundry water.
The inspector wants the "wall sconce" drain replaced with a real roof drain.
Obviously there will not be room for traditional flashing. Also, the drain is very close to the edge of the porch: not much room for flashing there, either. I'd really _hate_ to have to mess with replacing the scupper, though there might be a clever way of extending it.
The roof of the porch is composed of tongue-in-groove slats covered with some metal sheet: not sure copper or steel. Overall thickness is about 1/2-3/4". We do plan to re-roof with torch-down at some point.
So, first off I'm looking for an appropriate roof drain. I found what seemed the perfect 6" square drain at one of the big box stores, but it's ABS and the inspector won't allow it due to UV considerations.
So far the only similar thing I've found in metal is a "promenade drain", specifically the watts RD-200-CP. But it's not clear to me how this will attach to the roof, seeing as the roof is so thin.
Also I'm looking for advice on flashing/sealing the thing in. Basically I'm just thinking of siliconing it in as best I can and let that be that.
So, any better component or installation ideas?
The first photo looks down into the "sconce" drain, the scupper can also be seen. The image is a bit distorted (too wide) due to uploading limitations.
The second photo shows the drain I'm thinking of using..
The third photo shows the "sconce" drain from inside the back porch.
Thank you in advance!
Last edited by mysterylectric; 10-26-2012 at 08:11 PM.
Reason: explain pictures