Tying gutter downspout together with above ground pvc?

[stickshift]

Update with pics for those who have been following along, jump to post #24.

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https://imgur.com/9mJosO9

This gutter downspout on the side of the house toward the rear, used to dump into this narrow strip of dirt immediately adjacent to the house. I trimmed the downspout and added the flex-a-spout extension. This is better, but I don't like having so much water dumped so close to the house. Between my walkway and my neighbor's walkway, there is a 6ft wide patch of earth, but if I'm going to the trouble of trenching under the walkway, I'd like to get the water more than an extra couple of feet away, and I don't want any issues with the neighbor since I'm not exactly sure where the property lines are. You can see gated entry to backyard, and I'd have to trench under 15-20ft of concrete to reach dirt, so that seems like a lot of work and seems like it would be difficult to manage the height of the trench when using a garden hose to trench that far.

https://imgur.com/9I2vPjS

On left side of this pic is the same downspout with flex extension, and on the right side of pic is front of house downspout that connects to pvc pipe that runs underground to the front yard, where there is downslope to carry water away from the house. So another option is connecting the rear downspout to the front downspout on the same side of the house. To create some fall between the rear downspout and front downspout, I think I'd have to run pvc pipe (3" is plenty large enough, possibly even 2" for one gutter?) above ground, and then tie into the existing underground pvc with maybe a Y connector? Kind of ugly to have pvc pipe running along the side of the house at a slight angle, but not sure how else I could approach this.

What do you guys think?

 

[mike93lx]

https://imgur.com/9mJosO9

This gutter downspout on the side of the house toward the rear, used to dump into this narrow strip of dirt immediately adjacent to the house. I trimmed the downspout and added the flex-a-spout extension. This is better, but I don't like having so much water dumped so close to the house. Between my walkway and my neighbor's walkway, there is a 6ft wide patch of earth, but if I'm going to the trouble of trenching under the walkway, I'd like to get the water more than an extra couple of feet away, and I don't want any issues with the neighbor since I'm not exactly sure where the property lines are. You can see gated entry to backyard, and I'd have to trench under 15-20ft of concrete to reach dirt, so that seems like a lot of work and seems like it would be difficult to manage the height of the trench when using a water hose to trench that far.

https://imgur.com/9I2vPjS

Another option is connecting to the drain pipe on the same side of the house, but near the front. The pipe runs underground to the front yard, where there is downslope to carry water away from the house. To create some fall between the rear downspout and front downspout, I think I'd have to run pvc pipe (3" is plenty large enough, possibly even 2" for one gutter?) above ground, and then tie into the existing underground pvc with maybe a Y connector? Kind of ugly to have pvc pipe running along the side of the house at a slight angle, but not sure how else I could approach this.

What do you guys think?

How deep does that front down spot drain go before turning? I'd get out there and figure out how much fall you can squeeze out of it.

I wouldn't do smaller than 3" but you only need about 1/8" fall/ft to make it work. Might be able to have it right at the surface at the start.

 

[stickshift]

How deep does that front down spot drain go before turning? I'd get out there and figure out how much fall you can squeeze out of it.

I wouldn't do smaller than 3" but you only need about 1/8" fall/ft to make it work. Might be able to have it right at the surface at the start.

I assumed it turns right away since there isn't a lot of fall in the front yard, but I'll dig to check.

 

[545_days]

I wouldn't go smaller than 4", but I'm in SE Texas where torrential rain off the Gulf is not uncommon.

 

[pima67]

As far as ugly goes, you can paint it (but consul wife first on color. If expose to sunlight should paint it anyway.

 

[Skyman]

I would start by determining how deep the front downspout goes before the turn. It should be easy to figure that out. Bear in mind the possibility of freezing in the winter if you run it above-ground. I have a very similar situation. I ran 3-inch PVC above ground because the alternatives were very problematic. This past (very cold) winter, it froze up and shattered one stick of PVC and an elbow. Not a difficult repair to make - just a nuisance.

 

[stickshift]

I would start by determining how deep the front downspout goes before the turn. It should be easy to figure that out. Bear in mind the possibility of freezing in the winter if you run it above-ground. I have a very similar situation. I ran 3-inch PVC above ground because the alternatives were very problematic. This past (very cold) winter, it froze up and shattered one stick of PVC and an elbow. Not a difficult repair to make - just a nuisance.

You used Sch. 40 PVC? I assume the break didn't occur from water freezing (because there shouldn't be any more than a trace amount of standing water), but from the PVC joint freezing and cracking?

 

[HotRod68Camaro]

I would start by determining how deep the front downspout goes before the turn. It should be easy to figure that out.

I would start here as well. You may be able to tie in right below that front downspout. I have all by two of my downspouts on their own 4" lines. I'm glad I did because the recent weather here in central texas put it to the test. I wouldn't go less than 4".

 

[Skyman]

Yes, I used three inch schedule 40. I think it’s possible that water got into the joint, froze and blew it apart. It’s also possible that ice accumulated in the pipe gradually. It got wicked cold here, and the pipe has barely enough fall to it to ensure drainage if the water remains liquid. Trickling snow melt from the roof could have refrozen in the pipe.

 

[Skyman]

I would start here as well. You may be able to tie in right below that front downspout. I have all by two of my downspouts on their own 4" lines. I'm glad I did because the recent weather here in central texas put it to the test. I wouldn't go less than 4".

Area of the roof would have to be pretty large to overwhelm three inch pipe, especially if the downspouts are two by three. I had around 500 sf of roof on the back of my previous house that had a single two by three downspout. I fed that into three inch schedule 40, and it never backwashed once during the thirty years I lived there.

 

[no704]

First world problem. I don’t think I would loose much sleep over it

However I’d look at the actual gutter system and possibly divert the flow to an exit that is better equipped to handle the flow if there’s one.

 

[stickshift]

However I’d look at the actual gutter system and possibly divert the flow to an exit that is better equipped to handle the flow if there’s one.

Are you suggesting maybe angle the gutter differently to flow toward a different corner of the house?

 

[Skooterj]

Downspouts seem awfully close to each other to me. I would look into upsizing the from downspout to a 3x4 and closing off the back one. Short of that, I would not use ugly PVC and just run more aluminum downspout from the back into the front. Put a street T on the PVC and tie it in there. Or trench the back up to the front. Last thing I would do is leave a PVC pipe above ground.

 

[mike93lx]

Downspouts seem awfully close to each other to me. I would look into upsizing the from downspout to a 3x4 and closing off the back one. Short of that, I would not use ugly PVC and just run more aluminum downspout from the back into the front. Put a street T on the PVC and tie it in there. Or trench the back up to the front. Last thing I would do is leave a PVC pipe above ground.

Hard to tell without knowing what may be dumping into them. That back corner could have an upper roof coming into it

 

[stickshift]

Downspouts seem awfully close to each other to me. I would look into upsizing the from downspout to a 3x4 and closing off the back one. Short of that, I would not use ugly PVC and just run more aluminum downspout from the back into the front. Put a street T on the PVC and tie it in there. Or trench the back up to the front. Last thing I would do is leave a PVC pipe above ground.

I understood the part about upsizing front downspout from 2x3 to 3x4 and closing off rear downspout - that might be a good solution.

"just run more aluminum downspout from the back into the front."
I didn't understand this part. Please can you elaborate?

Hard to tell without knowing what may be dumping into them. That back corner could have an upper roof coming into it

Both downspouts are coming off the same hip roof.

 

[Skyman]

If both downspouts are being fed by the same gutter, that gutter should be sloping downward toward each of the downspouts. Closing off one end, without revising the slope of the gutter, will result in water pooling at the newly-created dead end. That would not be a great idea.
It would help if you could post photos of the entire picture, including the gutter(s) involved and the roof. What's the approximate square footage of the roof that's draining into the gutter(s) we're discussing here?

 

[stickshift]

If both downspouts are being fed by the same gutter, that gutter should be sloping downward toward each of the downspouts. Closing off one end, without revising the slope of the gutter, will result in water pooling at the newly-created dead end. That would not be a great idea.

Understood, thanks. I would check the slope of gutter using a garden hose before going that route.

It would help if you could post photos of the entire picture, including the gutter(s) involved and the roof. What's the approximate square footage of the roof that's draining into the gutter(s) we're discussing here?

Here's an overhead shot. Two downspouts for this hip / upper roof, both downspouts are 2x3. Gutters along entire front, rear and left sides of this hip roof. On right side of hip roof (where it meets the lower gable roof), gutters extend several feet inward from front and rear - you can see the white perimeter, that's the gutter. So essentially all of the rain that lands on this hip roof drains down the 2 downspouts in question. Not sure of square footage, but 3 bedrooms, master bathroom, and a common bathroom under that roof.

https://imgur.com/PKEKD8n

 

[no704]

Are you suggesting maybe angle the gutter differently to flow toward a different corner of the house?

Yes

 

[Skooterj]

If both downspouts are being fed by the same gutter, that gutter should be sloping downward toward each of the downspouts. Closing off one end, without revising the slope of the gutter, will result in water pooling at the newly-created dead end. That would not be a great idea.
It would help if you could post photos of the entire picture, including the gutter(s) involved and the roof. What's the approximate square footage of the roof that's draining into the gutter(s) we're discussing here?

Yes, the gutter slope would need to be addressed.

I understood the part about upsizing front downspout from 2x3 to 3x4 and closing off rear downspout - that might be a good solution.

"just run more aluminum downspout from the back into the front."
I didn't understand this part. Please can you elaborate?


Both downspouts are coming off the same hip roof.

Sorry, I would elbow the back downspout about halfway down and tie it into the front downspout instead of running PVC.

 

[Skooterj]

Best photo I can find quickly.

 

[stickshift]

Best photo I can find quickly.

Got it, thanks. Seems that would be more visually distracting than PVC run along the ground. And the pvc can be painted to make it blend in better. I'd need to paint it anyway to give it some UV protection.

 

[Skyman]

That appears to be a lot of roof area. More than I would try draining into a single downspout, even a 4x3. And I think it might be more than a single 3-inch pipe could carry in a heavy rain event. I wouldn’t eliminate a downspout, or feed both of them into one 3-inch pipe.

 

[CraigStu]

You can paint down spout also. For some reason I'd rather look at downspout in a slightly unusual orientation than look at pvc. But I also agree, that is a heck of a lot of roof to funnel it all into one pipe.

 

[stickshift]

Update with pics of existing PVC drain pipe for front downspout. Looks like a 4" x 3" reducing elbow. I think the consensus here is I shouldn't tie a second 2x3 downspout into one 3" pvc drain pipe (pic of roof in post #17). May need to refresh to see all 4 (3 below, and 1 near bottom) pics in this post.

https://imgur.com/yO5URl6

https://imgur.com/8UPv38K

https://imgur.com/TwueLx3

Another potential option is running a separate 3" pvc pipe for the rear downspout, and run it under the walkway adjacent to the pvc pipe for front downspout. But as you can see from the above pics, there are a lot of roots in this area. Other side of walkway will be even worse, as there is an evergreen bush very close to where the pipe would run. In pic below, the brick laid across the stone shows where the existing pvc pipe runs. A second parallel pipe would run directly toward the trunk of the bush. So even after pulling the bush, that area under the border stone and the walkway will be full of roots.

https://imgur.com/m3cS0me

The walkway itself is 53" wide, and with the border stones is 62" wide, so call it 5ft. I don't think the water jet + hammering pvc pipe method is going to work with all the roots. I've seen pneumatic horizontal boring tools, but I think running this just under the walkway would risk the tool pushing some of the roots up and damaging the walkway. Seems like the roots would need to be cut (as in shredded, maybe with a big drill) or pulled, but that's just speculation on my part.

 

[BombShelter]

I always recommend Sch 40 with a minimum of 4" dia. but 6" is much better. You'd be surprised how much water can flow off a roof, every 2-sq/ft x 1" of water is something like 1.25 gallons. I'd also run heat tape through there, in the winter it will freeze and you'll have an ice rink next to your house. I'd also get someone out to enlarge the downspouts to 3x5, I haven't seen the smaller downspouts in years, up here they can't handle the bigger rains.

 

[stickshift]

The walkway itself is 53" wide, and with the border stones is 62" wide, so call it 5ft. I don't think the water jet + hammering pvc pipe method is going to work with all the roots. I've seen pneumatic horizontal boring tools, but I think running this just under the walkway would risk the tool pushing some of the roots up and damaging the walkway. Seems like the roots would need to be cut (as in shredded, maybe with a big drill) or pulled, but that's just speculation on my part.

Any suggestions on how to bore a hole through the roots?