Gutters vs copper boxes for a flat roof?


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Old 04-07-16, 09:56 AM
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Gutters vs copper boxes for a flat roof?

So as I sit and type this it's raining outside and rivers of water are splashing over the sides of my flat roof in various areas. There is no gutter system and the pitch varies so the water leaves in odd spots.

Had a roofing guy suggest I install copper boxes for the larger exit areas. Never heard of them until this and have since seen them on Google. I'd have to install perhaps six to handle the worst of it. They are pricey being made of copper and installation will be a major job.

The alternative is standard gutters but only in short sections where the water cascades over the edge. Much cheaper and easier than the copper boxes but I'm not sure they will be able to handle all the water with much it is spilling out and over just as now.

What can anyone tell me about how to decide which is best for my situation?
 
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Old 04-07-16, 10:12 AM
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It would be a lot easier for us to offer suggestions if you gave us pictures of the whole roof area so we can see the issue.

http://www.doityourself.com/forum/el...-pictures.html
 
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Old 04-07-16, 12:05 PM
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It's just a large flat membrane-type roof with no edging around the top save for a small maybe 1/2" lip that is suppose to guide the water to one side. It really does not since the roof is not pitched correctly. You can see in this pic how the water is collecting near the satellite dish to go over the side.

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All I can do at this point is collect what is pouring over so that it comes down a pipe and not gushing over the edge and splashing back up on to the stucco wall, removing the paint in spots.

There is a 12" overhang all around the building so I do not have to go inside with the piping. Will boring holes to install a drain on the roof near the edge where the water seems to run to (within this overhang) work better than traditional gutters?

Thanks!
 
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Old 04-07-16, 12:40 PM
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Seems to me a standard gutter would be better than trying to put a bunch of scuppers around trying to hit the right spots. The spill over spots could change with wind and rain direction. But the raised lip is going to impede drainage into a gutter, can it be removed?

Probably either way is going to be only a partial solution until the slope issues and low spots are corrected. But that probably mean replacing the membrane, or building a new assembly on top.

Let's see what some of the others here have to say.
 
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Old 04-07-16, 01:48 PM
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... the raised lip is going to impede drainage into a gutter, can it be removed?


The lip is part of the edging. I assume it goes under the roof material for a few inches. Some sides have it and some do not. Presumably those are the sides the water should run off on.

It's raining heavy right now and what I have are a few areas where it is coming over in sheets. I'd say there are maybe four spots about 3 to 4 feet where a section of gutter, if you feel that best, might help mitigate the problem. Direct most, if not all, the water to a down spout and away from the walls, walkways,etc.

I'd need a good, wide gutter or some type of long metal box with a port for a down spout at one end.
 
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Old 04-07-16, 04:46 PM
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I'd suggest a commercial gutter. The flashing in front shouldn't have had a lip. The lip is used on gable ends, where you want to prevent water from running off the edge and direct it down to the bottom. Gutter apron should have been used there. A good epdm roofer could replace that, if needed.
 
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Old 04-07-16, 04:56 PM
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The installer can put a raised splash shield all along the top front edge if necessary to prevent the water from shooting past the gutter, but I doubt it would be needed with such a low slope.
 
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Old 04-08-16, 09:06 AM
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Thanks for the advice. Will try to get some quotes.
 
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Old 04-22-16, 05:04 PM
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pooling water

I have had similar problems over the years with my flat roof pooling water. I recently re-roofed but the expense to re-engineer a slope to the existing roof or set up some complicated drain system was not feasible. So I came up with a $20 dollar solution.

I purchased 100 ft. of 1/4" drip hose and ran it from the low spots on the roof over the edge to the ground. I placed a small screen mesh over the end and placed it the deepest spots. I then weighed it down with a small brick to keep it stationary. You can also glue down the hose to the roof in spots to keep it from moving.

I took the other end and draped it over the roof to the ground and fitted the tips with a plastic connector. I then purchased a pump siphon on Amazon for $10 bucks. ABN Multi-Use Siphon Fluid Transfer Pump Kit for Gas, Oil, Liquid, and Air

After a heavy rain, I attach the ends of the hoses one at a time to the siphon and give a few pumps and let gravity do the rest. The water starts running out in a steady stream. I just leave it draining on the ground until it stops. Its not quick but in a few hours its done draining.

Attached is a crude video I made of the process. Its not the most elegant solution, but it just takes 5 minutes after a heavy rain to keep the flat roof fairly dry instead of taking days to evaporate.

https://www.dropbox.com/s/yki5bikqkovyggl/GLENNPUMP.mp4?dl=0
 
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Old 04-25-16, 11:59 PM
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As I see it you have wo issues. 1, uncontrolled water cascading over the edge of the roof. 2. Remaining water pooling, which is detrimental to the life of the roofing membrane.

A properly installed gutter system, possibly with deflecters or splashguards fixed to the outside edge to prevent overshooting, would be a relatively inexpensive and simple solution to the cascading issue.

The pooling issue will remain, even with a gutter (or box) system. Sweeping, pumping or other methods might work but a re-engineered sloped roof is the appropriate remedy in the long term, which could be installed over the top of the existing roof without tear-off.
 
 

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