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sportprog2
Help! Gutter not catching all of roof's water
sportprog2

Hello,
We recently finished a U-shaped 11x18’ addition. The roof is rubber, appears flat but actually has slight pitch/angle which carries water into one gutter along the bottom of the U (the 18’ width) with downspouts on both ends. Strangely, the gutter ends about one inch BEFORE the end of the width of the addition. One side of the gutter seems to catch most of the roof water but the other side does not. As a result, water sprays off the side of the addition, doesn’t make it into the gutter and forms a large puddle next to the bottom of the downspout. We have mentioned repeatedly that we believe the gutter was cut too short and should have extended at least an inch BEYOND the roof line. After much pestering, our contractor agreed to try to fix by installing (humble looking: 6-8” long and less than 2” high) rain diverters on both ends of the roof that empty into the gutter, but they aren’t effective – water still drips off the side and forms a puddle. Is the only solution to tear down the current gutter and install a wider gutter that would better catch the water? I have searched for terms like “gutter extenders” but cannot find possible solutions. While the contractor’s work is still under warranty, we do not trust him at this point so are seeking outside feedback and might even consider having someone else correct it the right way.
Thank you!

dj1
Re: Help! Gutter not catching all of roof's water
dj1

Without seeing what you got, it sure sounds like you were shorted by the gutter man.

Did he install one piece of gutter from one end to the other, or did he install sections (usually 10' long)?

sportprog2
Re: Help! Gutter not catching all of roof's water
sportprog2

Thanks for the reply. I just looked and it appears to be one big 18' piece. I could not see any seams across the gutter.

HoustonRemodeler
Re: Help! Gutter not catching all of roof's water
HoustonRemodeler

The gutter installer measured wrong and needs to make a new one.

sportprog2
Re: Help! Gutter not catching all of roof's water
sportprog2

Thank you Houston Remodeler. I was hoping there might be some type of extender piece, but we might have to have someone install a longer gutter.

dj1
Re: Help! Gutter not catching all of roof's water
dj1

Quote: " I was hoping there might be some type of extender piece "

Actually there is a remedy without replacing the whole thing, but you may not like it as much, and frankly, it won't look good at all on a 1" extension.

The piece of gutter for the job has to have a matching profile to the existing gutter, should be about 1" + 4" long. Use the end cap on the gutter to seal the extension and caulk it with roofing caulk.

If it were me and if the gutter was visible, like in the front of the house, I would prefer one piece gutter. Call the gutter man to discuss your and his options.

Mastercarpentry
Re: Help! Gutter not catching all of roof's water
Mastercarpentry

Back to the old "looks best" vs "works best" paradox. The gutter must extend to at least the end of the roof to work correctly. End caps inset about 3/8" so the gutter must be at least that much longer than the roof edge to catch all the water and work properly. It does look a bit odd but not that bad; the main thing is that it works properly. Most gutter installers cut the gutter to actual length, so once the endcaps are on they don't catch all the water but they match the house. Normally this isn't a problem. I'll bet your gutter guy doesn't do many commercial installs; he doesn't seem to know the quirks of flat roofs!

Wind-blown water across a flat roof can go quite a distance away from the roof corner so normally wider gutters are used and they are installed as high as possible to mitigate this effect. Based on the roofing edge detail the height may be limited, in which case the usual compensation is additional width. Also the gutter size and minimum number of downspouts is dependent on the square footage being drained and yours seems very minimal- another "looks" issue as well as a way to keep costs down.

Unless you specified exactly what you wanted, you may find it tough to get the installer to re-do the side runs although if they are short (which they seem to be) you have a solid argument. If they are not mounted as high as possible the same applies- the installer should have known better.

The installer can add extensions at the ends easily but you need the same guy for that- each gutter-forming machine produces a slightly different profile due to adjustments and wear so only his stuff will give a perfect match to his stuff, though others may be close enough. It won't be 'seamless' anymore but if done well it will work just fine.

If the gutters are too low due to the roofing edge, a 'fence' of "L" shaped metal can be made, then sealed and screwed to the top outer lip of the gutter so that they will catch more water. The 'fence' is usually level with the roof at the lowest gutter level; it doesn't hurt to have it higher elsewhere. Because the gutter installer did nothing wrong in that case you may have to pay for that but here all you need to do is match the color so any gutter company who has a metal brake can do this. Especially here you must never lay a ladder on that gutter; the 'fence' is easily bent Fenced gutters must be kept clear- water can build to above the inner edge of they clog, but from a flat roof this maintenance is easy.

If the gutters could have been installed higher but weren't, that's his problem and he should raise them for free. If they still need a 'fence' he should do that for free too; it should have been a known need and included in his price. Once again this is not a normal house-type installation and he should know what he's doing before taking on something he's unfamiliar with which apparently he didn't.

And now you know what can happen when you don't specify exactly what you want with contractors (preferably in writing). We're not mind-readers and there are a heck of a lot of folks in the business who don't do quality work because they either don't know what it is or don't care about anything but their profit margin today. Your being specific keeps you safe from problems like this and keeps both of us happy in the end :cool: The better contractors will discuss the specifics with you before they make a quote- we want you to understand what we want to do and why, and we too don't like you having problems when we're done. Just one way of spotting the good guys among the not-so-good ones.

Phil

llmotoll
Re: Help! Gutter not catching all of roof's water
llmotoll

Agree with what Phil says.

what about the other side of the roof? can the gutter be shifted over to one side to catch the water? maybe it does bother you if water comes off the other side? maybe water does not drain off the other side in that 1" portion of the edge??
the distance from the roof edge to the top of the gutter should only be about 1" - 2" for a flat roof.

From reading your description of the gutter it sounds like a standard continuous residential gutter was installed.
FYI... industry standard flat roof gutter is nothing like gutters found on shingle roof/steep slope roof systems.
Flat roof gutters are typically hung level into 1/4" steel hangers 30" OC with internal straps off set 30" OC and do the standard size is 6" x 6" with down spouts install based on volume of water evacuating from the roof system.
Are there other steep slope roof sections draining onto this flat roof section?

Another solution would be to install a gravel stop drip edge and with scupper cut outs. this would control the evacuation points from the roof and force the water into the gutter. In most case this detail can be an addition to the existing system assembly without doing selective demolition.

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