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Tying Roof Drains Into the Footer Drain

R801.3 Roof drainage. In areas where expansive soils or collapsible soils are known to exist, all dwellings shall have a controlled method of water disposal from roofs that will collect and discharge roof drainage to the ground surface not less than 5 feet from foundation walls or to an approved drainage system.

Not a good idea. In fact it is a horrible idea but searching the code does not turn up a violation. It should be. It’s probably there and I didn’t find it. Here is SoCal we seldom have foundation drains except with retaining walls. Basements are rare.
 
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I liken the practice of tying them together as standing in a stream fishing with waders on to keep my feet dry holding an inverted umbrella with a hose leading down into my waders.

Or put it this way; the footing drain is to channel water away from the building foundation, why would you wan to direct water there?
 

R405.3 Above-Grade Drainage​


Above-grade drainage systems, including but not limited to, gutters and downspouts, roof drains, and yard drains, shall not be connected to the foundation drainage system.

FWIW, you should be able to "downstream" with some type of backwater or check valve.....So you don't have to parallel all the way out to the discharge....Maybe I'll work on that code change...
 
Storm drainage and footing drains need to be kept separated all the way until they discharge to grade. Otherwise storm drainage could back up into the footing drain if the common pipe got clogged.
 
steveray said:

R405.3 Above-Grade Drainage​


Above-grade drainage systems, including but not limited to, gutters and downspouts, roof drains, and yard drains, shall not be connected to the foundation drainage system.

FWIW, you should be able to "downstream" with some type of backwater or check valve.....So you don't have to parallel all the way out to the discharge....Maybe I'll work on that code change...
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California Residential Code does not have R405.3
 
I had to dig into the Canadian Codes for a bit, because I knew in Canada this is wrong, but I couldn't quite find the code for why.

Turns out roof drains are covered by our national plumbing codes..... and it's wrong. Downspouts have to be aimed either to a storm sewer or away from a building in a way that mitigates erosion. FYI.
 
I always like separate lines, but my civil engineer has been combining them for years. In any case, I have him separate them until they are away from the foundation, then drop them into a Christy Box with one outflow (at a lower elevation). This allows visual inspection and cleanout.
 
Robert said:
I always like separate lines, but my civil engineer has been combining them for years. In any case, I have him separate them until they are away from the foundation, then drop them into a Christy Box with one outflow (at a lower elevation). This allows visual inspection and cleanout.
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Help me out. I get zilch when I Google Christy Box. Perhaps a West Coast colloquialism.
 
bill1952 said:
Help me out. I get zilch when I Google Christy Box. Perhaps a West Coast colloquialism.
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Yes, although my first Google hit is on point:

oldcastleinfrastructure.com

Christy® | Oldcastle Infrastructure

The Christy® product line delivers reliable, and cost effective, hand holes, valve boxes, meter boxes and vaults to the utility market. Christy® concrete products have been the preferred and trusted choice of the utility market for over 40 years.
oldcastleinfrastructure.com oldcastleinfrastructure.com

Cheers, Wayne
 
Introduced a code proposal for the 2024 IRC to address this issue and it was denied. The weak reasoning they gave was "it is a local issue". But look forward to it again for the 2027 IRC cycle
 
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