Home>Discussions>EXTERIORS>Non-standard downspouts and drain sizes, but need to extend them
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deepomega
Non-standard downspouts and drain sizes, but need to extend them

This old house has some weird, non-standard downspouts. Flat roof, no gutter, so the roof slopes to an opening in the wall. The main house has a downspout connected, but the garage doesn't. In both cases, the shapes are not at all normal downspout profiles, so I'm not sure how I can properly prep this to drain farther from the foundation. (Right now even a moderate rain leads to a small leak in the garage.) The garage's drain is a 5x5" sheet metal square.

Anyone have any experience with this kind of set up?

keith3267
Re: Non-standard downspouts and drain sizes, but need to extend them

What you are describing is called a scupper. Many times these are architectural elements for the building so they may not be standard. Not sure exactly what you want to do here but you might find some ideas if you just google "scupper".

Sombreuil_mongrel
Re: Non-standard downspouts and drain sizes, but need to extend them

I wonder if you could get a 4x6 downspout and reshape the end to connect to the old work. Or get a sheet of galvanized metal at HD and make up a transition section so a standard size fits, but the danger there is that if you go from larger to smaller on drains, you establish clog points where stuff accumulates or jams.
Casey

Mastercarpentry
Re: Non-standard downspouts and drain sizes, but need to extend them

Check with a commercial gutter supplier for a real "collector box", not the appearance-only ones applied over residential downspouts. You will have to figure out how to mount it and cut the back out to match what you have, but it will open at the bottom to a standard size downspout and look better than the scuppers at the same time. Or you can commission a local sheet-metal shop to fab something which you draw up for them. Also be aware that dissimilar metals can corrode from electrolysis at the connection so if you can't match the metal, isolate the new from the old physically to alleviate this.

Phil

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