How many downspouts I need?

[Emac]

We have a mid century modern quad home with a low pitch roof. To better explain my concern I’ll take a photo of the house tomorrow and post it. We just replaced the roof, which is basically 2 rectangle areas (the smaller area is about 1/3 of the roof surface and the longer area about 2/3. The Smaller roof area has 1 gutter and one downspout, the bigger area had 1 gutter and 2 downspouts.(one at the north and one at the south corner of the garage).
We decided to replace the gutters and to have one spout instead of two for the bigger roof area because... the house is on a bit of a hill and in the case of a heavy rain, the water from the north side spout had a tendency to come back towards the garage. Now we are not sure having only one spout for such a big roof area was a good idea. We live in Michigan, so the winters are really winters here and I’m worried about the amount of snow and ice melting on the roof and having only one spout. Should we add back the second spout and is there a way to maybe adjust the gutter so some of the water goes through the north side spout but most water to go through the south side spout ? Any advice is appreciated. Thank you

 

[oldognewtrick]

How many feet long are the gutters?

 

[slownsteady]

You may also need to address what happens at the bottom of the downspout.You could raise the ground in that area or you can add an underground drain pipe to move the water past the house and to lower ground.

 

[Emac]

 

[Emac]

How many feet long are the gutters?

I think the gutter is definitely more than 20 feet long, maybe if you look at the photo I posted.

 

[Emac]

How many feet long are the gutters?

There is only one spout now, the other one was at the front corner of the garage, coming down the wall next to the tall narrow window, and on the red mulch towards the tree. The roofing guy asked us if we wanted one or 2 spouts, we said one because we didn’t want the risk of the water after a heavy rain to come back towards the garage. But being in Michigan and a lot of snow(or ice) melting, we decided it’d still be better with 2 spouts, so i texted them. I think they missed my text or something because they installed 1 spout. I hope they can still change it. Or should I leave it with one spout? The other side of the house has only spout, but the side of the roof that drains that way is much smaller. I’ll attach a photo of the front...

 

[slownsteady]

That seems like a lot of roof for just one downspout. Does the gutter ever overflow? And what diameter is the downspout? They are usually 2x3 or 3x4. Problem with adding another downspout now is the the gutter isn't pitched properly for both.

 

[Emac]

That seems like a lot of roof for just one downspout. Does the gutter ever overflow? And what diameter is the downspout? They are usually 2x3 or 3x4. Problem with adding another downspout now is the the gutter isn't pitched properly for both.

I think the gutter is 6” wide(more than 20 feet long) and the spout I think is 3x4 because it’s wider than a regular one. We just had the roof and gutter replaced, and no overflowing when we had heavy rain. It might have overflown before(with 2 spouts), butbecause of improper installation. (We had 2 spouts before and we wanted 1 now for reasons I posted earlier) We later changed our mind, texted them that we wanted 2 spouts, but we didn’t know when they were going to install them so we weren’t home to talk to them... next thing we know we got home one day gutters and spouts were installed with only one spout. I know the gutter isn’t pitched properly for both, and they’d have to unhook some of it to adjust the pitch. My hubby said to leave it like this, but I don’t know, since it’s a big expense, I want to be happy with the job and I texted them we wanted to go with 2 spouts. (it was a short text but still...). I’m worried about snow and ice in the winter, they didn’t melt fast on our low slope roof before, and if on top of that, all that melts has to go towards one spout now?! (I wish they’d have told us what’s better instead of going with what we wanted) Should I insist to them to put the second spout(and adjust the gutter pitch) since I did text them about it? Is it that hard to fix that? Or am I worried for no reason, should I forget about it, maybe with the new roof, the snow and ice will melt and drain faster than before?

 

[nealtw]

As long as the slope is not more than the depth of the gutter you can put 2 side by side . But where 2 are called for here the often just install one bigger one.

 

[bud16415]

Little off topic. Did they do a rubber roof? Does the wind keep most of the snow off the roof? How much snow have you seen on the roof?


I would be more worried about ice dams etc.


If the pitch is slight a gutter on the high end will still help in the overflow situation when the down spout can’t get rid of it fast enough. If that’s the case the normal flow would go out the way you hoped it would and when a lot of water came at once you would have a extra path out.


Make sure you keep the gutters free of leaves.

 

[jeffmattero76]

If it is seamless gutter (they usually form that on site), it will be impossible to adjust the pitch and add back the second downspout. Essentially, you would have to create a seam in the gutter so that it could be re-hung with slope in both directions.

If it is in sections (usually sold in 10 foot lengths at the big box stores), then it should be relatively easy to re-hang and add a downspout.

As an earlier poster stated, even if the gutter is not pitched correctly, you could add a second downspout on the uphill end, and it will serve to take excess water that builds up in a heavy storm. In other words, in a heavy storm you may have a couple of inches of water in the gutter. Since water seeks it's own level, some of that excess would go to the uphill downspout.

 

[Emac]

To answer some of the questions... the new roof it’s not rubber, but we put a more expensive and thicker underlayment(than the ice and shield one). Also, the old gutter had slopes in both directions and 2 spouts, one at each end and from what I remember was a one piece.
The new one is one piece too. Isn’t the material flexible enough, especially for 20+ feet length, to have slopes in both directions, without having to be cut?
Btw We already had a heavy rain and no problem. I’m more worried about snow and ice. The wind has blown the snow off many times before, but other times we had a foot of snow on the roof for weeks. About ice dams, if the ice melts at the end that has no spout and the ice doesn’t melt at the end that has a spout. How will it drain?
If they had noticed my text about wanting 2 spouts instead one (as initially planed) we wouldn’t be here now... I want to ask them to put the second gutter, but I don’t want to pay extra since they are the ones that missed my text(or maybe they didn’t read it carefully). They’ve been very good with everything so far, so maybe I should try talking to them.

 

[nealtw]

Did you ever have a problem with the gutter freezing before, if not 2 x 0 is still 0

 

[user 4883]

well if it ends up costing you extra then just wait and see what happens this winter and then make your decision to keep it or change it when spring comes.