# Gutters with Underground Drainage



## pyper (Jul 1, 2009)

It will be interesting to see what the experts say on this.

My gut says that it's just water, so it really doesn't matter.


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## DexterII (Jul 14, 2010)

As Pyper said, it will be interesting to see what the experts have to say, but, in the mean time, here is how I would look at it. Assuming that you are draining approximately 2,000 square feet of roof, which I would guess is close, based on your draing, an inch of rainfall per hour, which is pretty significant in my opinion, will produce approximately 1,250 gallons of water per hour. So, breaking that down a bit more, you would be draining between 20 and 21 gallons per minute. Now, can the system that you described handle this amount of water? Well, I'm not a plumbing or drainage expert either, but, as long as everything has sufficient pitch, and I would consider 1/8" or more per foot sufficient for this purpose, and your popup works as intended, I think you are in pretty good shape.


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## AllanJ (Nov 24, 2007)

Click the QUOTE button and scroll through the gray box to see the diagram in its full glory.


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## AllanJ (Nov 24, 2007)

One problem with underground lines of this kind is that they could freeze and break underground unless buried more than about 3 feet. This problem is lessened although not completely eliminated if the pipes ave a continuous downslope (no hill and dale).


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## the_man (Aug 14, 2010)

pretzels said:


> I recently had gutters installed along with underground drainage for them. The downspouts drain into 4 inch drain pipe, which runs away from the house, where we eventually plan on collection the rain in underground or above ground cisterns.
> 
> I was digging up dirt in the vicinity of these drain pipes, and I noticed that they used a plumbing T where I would think they should have probably used a combo-TEE (the one where the center pipe attachment is curved.)
> 
> ...


nice, looks much better in the quote box :thumbsup: is the concern having a straight tee instead of allowing for direction of flow? i've seen it done like that quite a few times so i would assume that it's ok. i have no code sections or anything to quote for that though


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## maxfischersweet (Nov 18, 2009)

AllanJ said:


> One problem with underground lines of this kind is that they could freeze and break underground unless buried more than about 3 feet. This problem is lessened although not completely eliminated if the pipes ave a continuous downslope (no hill and dale).



Well they are basically right under the dirt, so they are not deep enough to prevent freezing. It is all sloped in one direction pretty good, i even think the 4 feet pipes from the downspout are sloped as well. Plus I live in Texas (not much rain, and not much freeze). Although the past 2 years you would think i lived in Colorado with the snow storms and 0 degree weather.... So I don't know if this would really be that big of a problem.

Thanks for the positive comments about the diagram.


By the way. I am wondering all of this because when i was digging up the dirt for the sidewalk and patio I am putting in, I had to use a pickaxe to loosen the dirt.......you know where this is going.....Yep I hit the 3-4 foot pipe sections connecting one of the down spouts to the main drain pipe. So I have to fix that. (They buried it in a different spot then they said they did...)

What would be the best way to fix that. Its only about a 4 inch slash in the pipe. Should I just cut that section out, and use a piece of pipe with the bell end on one end and a coupler on the other?

Thanks.

I have a question about gutter downspout and cistern, but I will make another thread.


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## AllanJ (Nov 24, 2007)

Oops, just found out that posting the quote will not display the diagram properly. You have to look at the diagram during the time you are pretending to add a reply.

Come to think of it, a slash in the top of the pipe probably won't hurt. If it is a big hole, put something like a flat rock over it to help keep dirt out.


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## pyper (Jul 1, 2009)

DexterII said:


> Now, can the system that you described handle this amount of water? Well, I'm not a plumbing or drainage expert either, but, as long as everything has sufficient pitch, and I would consider 1/8" or more per foot sufficient for this purpose, and your popup works as intended, I think you are in pretty good shape.


Our roof is about 2000 SF, and we get some big rains in South Carolina. Everything goes out to some 4 or 5 inch corrugated flex pipe in the yard, and it generally works. When they put in the new carport (adding 250 SF or so) they added a cleanout near the house. Once, when it was raining seriously hard (probably more like 2" per hour), the water overwhelmed the system and it bubbled up out of that cleanout.

I don't know which part of Texas the OP lives in, but our frost line is only about 12" here in my part of SC. When it's cold enough to be frozen down to the frost line depth we don't get a lot of rain.

As far as your hole, you could just put a piece of rubber on top of it and cover it. The weight of the dirt will seal the hole. That wouldn't work at the bottom of the pipe, but it will probably be OK at the top. Or you could cut out the pipe and replace it. I'm assuming it's PVC. If it's corrugated black flex pipe then it leaks at the joints anyway.


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## maxfischersweet (Nov 18, 2009)

its pvc. the thin stuff with bell ends. 

It seems pretty flimsy. Will this be ok to put a patio over. Its just made out of gravel screenings and 1'x1' concrete square blocks. About 10' of the main pipe will be under this patio. and it will only be a couple inches under it towards one side. It doesnt even seem strong enough to walk on, even when its buried. I would have used schedule 40...

I have a problem with over engineering things. Which isnt a problem for me when i do things, but when i hire others to do things, it is really annoying. Because i am expecting it to be done one way, the best way that will hold up the longest with little problems, as well as the anticipation of problems and the installation of things for future access to correct future problems. Why wouldn't you do it the best way. This is just my first time working with people and hiring people to do things. I live in the middle of nowhere where I always end up with some guy who yes, has experience doing what he does for a long time, but, does it the cheapest easiest way, with out talking to you or giving you options. And since they are the 'expert' and my wife wants me to hire someone who "knows what they are doing" and "hates me dragging things out" because i want them to be done correctly and with pre planning for problems in the future. I end up assuming they know what they are doing. 

Building a new house, and have only been satisfied with the electrician, and the only thing left is painting. Which is taking place today, in cold humid weather.....cant wait to see how that turns out...


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## DexterII (Jul 14, 2010)

We installed our system at an average depth of 3-4', ran it to daylight, and even incorporated a couple of risers with double elbows to allow for any over capacity conditions, so I certainly agree with Pyper that your system could be overwhelmed by a very heavy rain, and with Allan that proper depth is necessary. But, since you alread had it installed, my point was that, if it is sloped properly, it should work well enough most of the time, and probably was not worth the effort required to dig down and change from one type of fitting to another. However, based on subsequent posts, it sounds awful shallow to me, and, although it is hard to say, I cannot envision it having enough slope or pitch, and I would definitely determine that before moving forward with a patio, or anything else, that would make it more difficult to correct in the future. Since it was recently installed, and apparently not very deep, it shouldn't be too much of a job to dig down to it, lift it out, dig deeper, reset it, and backfill.


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## pyper (Jul 1, 2009)

pretzels said:


> Building a new house, and have only been satisfied with the electrician,


I heard that! 





DexterII said:


> However, based on subsequent posts, it sounds awful shallow to me, and, although it is hard to say, I cannot envision it having enough slope or pitch, and I would definitely determine that before moving forward with a patio, or anything else, that would make it more difficult to correct in the future.


That seems prudent. It's also easier to put in more capacity prior to pouring the patio! We put in pavers on a gravel bed for a walkway, but I wish it was concrete -- ants love the sand.


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## maxfischersweet (Nov 18, 2009)

So are yall saying the pipe needs to be bigger, or have more outlets, or just more slope.

DexterII, are you saying you did 3-4 feet deep? Thats a lot of digging into hard hard lay, for about 75 feet. haha. 

Also, the ground slopes with that pipe...Basically the back end of the pipe is 1-2 inches under the dirt, and by about 16 feet down its already about 6 or even more inches deep. Then from the front downspout it slopes really good down a major slope in our yard. 

I dont know if im big on the hole pop up drain thing. Seems like it would just cause problems. If i just cut that off, would that help the draining?

So i went to Lowes. In the drain pipe section, they had a TEE where the middle part has a screw in plug, for clean out. I bought it, i think i can just cut that broken section out and install this there. (Luckily the clean out part is extremely shallow, so it will end up just below the dirt/grass and it was the last one, in the very back, they had new ones where the clean out part protruded like 6 inches). I thought this was better than buying a whole 10' of pipe i would only use a tiny piece of with a coupler. Plus i have like butt loads of left over CRAP from the house building. I could possible build a guest house with. haha

I personally, would dig it up and place it deeper. I would change a lot of things, but i have a wife......who doesnt like me doing things around the house....which is weird, cause growing up, i thought wives wanted their husbands to do stuff around the house.....


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## DexterII (Jul 14, 2010)

Yes, we installed ours approximately 3-4' deep along the perimeter of the house, and then ran it to daylight, so it obviously gets shallower as it approaches the end of the run, but I graded a subtle berm along that area, in order to maintain something like an 12-18" minimum coverage. Now, we're in MI, and it's probably not necessary to go that deep in TX, but I would still maintain an absolute minimum depth of 12" at the top of the pipe, maybe more, depending on frost depth, both for freezing, as Allan mentioned, as well for protection, and to allow enough space for vegetation to grow, in case you ever want to look at something other than dirt in that area. Also, I assumed, apparently incorrectly, that your property was relativelt flat since you have a pop up diverter, but since you have slope, you are correct, in my opinion, to be rethinking that. I would eliminate it; let the water flow to daylight, and place a pile of rocks there, if you need to, in order to keep the flow from washing away soil. And, while you are at it, why don't you simply have each line discharge separately onto the ground, rather than running them through a common discharge? That would double your flow capacity, and eliminate any concerns whatsoever regarding whether or not the tee's are sufficent. As for your wife, well, I don't know what to say, my friend, except that maybe she would prefer that you lived in a condo, apartment, or other residence where someone else performs the maintenance. I believe that I can say that a vast majority of homeowners enjoy maintaining them, but more important than that, projects like this are money in the bank, because, left unchecked, they can cause serious problems down the road, in the form of soil erosion, water damage to the structure, etc. And I haven't even touched yet on the fact that it is already causing you to agonize over your next project, a patio. Sorry for being long winded, and sorry for not sharing some of these thoughts earlier, but, again, since the work had already been done, I was just saying that it would probably work fine most of the time, and couldn't see digging it up just to replace one or two components. However, now having more details, my suggestion is to get busy and do it right.


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## maxfischersweet (Nov 18, 2009)

haha, thanks.

I should add pics.

I would have them separately, but.

My house is on the side of a hill (well sort of), with a retaining wall thats about 8-10 foot tall and only about 10-11 feet from the house on 2 sides. (it makes an L shape) Both about 75 feet long.

The water needs to go away from the retaining wall. over or around. This is the attempt at going around.

I guess there could be 2 pipes....which now that i think of it, would be easy to add...just cap that tee there where the front meets the back and just add another pipe for the front.


The reason for one pipe, was to collect the water one day in an underground or above ground cistern. preferably the above ground corrugated metal ones.(you know one of my many many plans) but i guess i can join them into a bigger single pipe.

Which brings me to another question, but i should probably start another thread for that one. but here it is.

I have seen youtube videos of cisterns installed where the water goes down the downspout, underground, over to the cistern, up a pipe, and then into the top of the cistern. Im guessing this is a siphoning action. Either way our cisterns will be down hill from the gutters and downspouts. This works right? Will the downspout need to be a sealed pipe, or are the normal downspouts ok.


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## AllanJ (Nov 24, 2007)

If the downspout has to go up and over to get into the cistern then the downspout joints need to be sealed to not lose too much water.


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## maxfischersweet (Nov 18, 2009)

so i would probably need those galvanized pipe downspouts, rather than the corrugated 3x4 ones. Where do you get those at.....and what would be the best way to connect the it to the pvc in the ground


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## AllanJ (Nov 24, 2007)

Oops, I did not mean up and over as being on the surface of the ground but rather up an over as in going uphill and then back downhill like a roller coaster track.

Another oops, you cannot have any uphills in the pipe in cold climate; water will collect in the valley in between and freeze and break the pipe.


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## maxfischersweet (Nov 18, 2009)

it would be like this

http://www.youtube.com/watch?v=I3A4J7_9Hww

but about 30 feet from the house, and the top of the cistern would be about level with the slab of the house (base of the downspout) and the drain pipes ive been talking about.


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## AllanJ (Nov 24, 2007)

I can't watch video, takes too long on a dialup modem and also crashes my computer sometimes.


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## maxfischersweet (Nov 18, 2009)

yeah, thats whats really weird about where i live......out in the middle of nowhere,.....yet i have dsl.....

anyways.

In that video.

A down spout hookes into a drain pipe in the ground. The drain pipe goes about 10 feet from the house in the ground. Then 10 feet from the house, is the above ground cistern. The drain pipe in the ground comes out of the ground and goes straight up in the air. It curves over and dumps into the top of the cistern. And the top of the cistern is about between mid way up the downspout and the gutter (to get an idea of the height of the cistern.)


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## DexterII (Jul 14, 2010)

I am on dialup as well, so watched only pieces of it, and can't say for sure, but it looks to me as if they ran PVC all the way from the eaves trough to the cistern; no aluminum downspouts; so that it is a sealed system, which operates on the simple principle of water seeking its' own level. Sort of what I thought you might have in mind, and, in my opinion, theoretically should work, but a bit hard for us northerners to envision, because here it would remain frozen solid for 3-4 months per year.


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## DexterII (Jul 14, 2010)

And by the way, if you were to consider something like that, you should probably consider schedule 40 pipe, rather than the lighter weigtht drainage pipe, for the simple reason that with 8-10', or whatever they would be, vertical PVC for downspouts, I can imagine the drainage pipe not holding straight as well, and frankly not looking too good after a year or so. Also, you would have water standing in your downspouts 24/7, so what would that do to the mosquito population around the house between rains. Just some thoughts.


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## pyper (Jul 1, 2009)

DexterII said:


> I am on dialup as well, so watched only pieces of it, and can't say for sure, but it looks to me as if they ran PVC all the way from the eaves trough to the cistern; no aluminum downspouts; so that it is a sealed system, which operates on the simple principle of water seeking its' own level.


That seems to be it. Pretty wild. 

I think it's also important that the cistern is really close to the downspout. There's friction when water moves through a pipe -- the further it has to go, the slower it's going to move (gets back to that capacity issue) and that uphill leg will really slow it down.

You can probably keep the mosquitoes out of the pipe with window screen.


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## maxfischersweet (Nov 18, 2009)

alright, thanks a lot for all the help.

It might be a better idea just to have an underground one.......i have plenty of large holes to fill out around our house....haha

I just really love the look of those corrugated ones, but i could get a smaller one of those for a couple of smaller gutters i have.

thanks again


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