# Roof Drains



## msell24 (Oct 3, 2010)

Can anyone please tell me how to figure out how many roof drains are needed for a 60x1000 ft roof; in Indianapolis where the annual rainfall is 2.8 in./hr. If anyone has the formula for this I would appreciate it. I checked Appendix D in the UPC book and it only made mention of piping.

Thank you.


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## 130 PLUMBER (Oct 22, 2009)

How about an *introduction* first
http://www.plumbingzone.com/f3/


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## affordabledrain (Nov 24, 2009)

I will figure it out for you.

Just send $185.00 to my pay pal account


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## breid1903 (Feb 8, 2009)

one. breid.....................:rockon:


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## Redwood (Sep 8, 2008)

breid1903 said:


> one. breid.....................:rockon:


Yea a big one...:thumbup:


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## SewerRatz (Apr 25, 2009)

I say you need one every 5 square feet. Or you can do Three really large ones.

In all reality there is information missing. Why not post an intro letting us know more about yourself and the kind of plumbing you been doing , how long you have had your license? Then you will get some better responses to your post.

Thanks

Ratz


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## user4 (Jun 12, 2008)

Are they standard or control flow drains?

What is the parapet height?

What is the hundred year rain measurement?

What is the hundred year snow measurement?

What pipe size are you installing?

Is it a rubber or tar and gravel roof?


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## SlickRick (Sep 3, 2009)

I am going with Scuppers and down spouts.


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## Airgap (Dec 18, 2008)

Put in a pit and pump it over the side....


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## Ron (Jun 12, 2008)

1/4" per foot, 1/4 turn


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## Tommy plumber (Feb 19, 2010)

Minimum of (4) drains if sq. footage of roof is over 10,000 sq. ft. You will need secondary (emergency) roof drains also, which need to drain to an alternate point of discharge separate from primary system. Usually a lamb's tongue in parapet wall accomplishes this, ( at least in FLA. Not sure about where you are in the frigid north). Tables in code book will show size of vert. and horiz. storm drainage piping based on amount of rainfall rate and sq. ft. of roof area being drained into each roof drain. Hope this helps.


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