# Drainage, Downspouts, Flat Lot Fun....



## markeyro (Jan 18, 2011)

Hello,

So here's the scenario:

We have a very flat lot in a "marshy" neighborhood. We're on a 2 block crawl (read: very tight and no fun to be in) and our soil is clay all the way.

I was going to have my entire crawlspace encapsulated and still may at some point, but finances don't allow for it right now as I need to put some peirs in on 2 corners of my house to keep it from continuing to sink.

That said I am planning on trenching the entire exterior perimeter of my house down 18-24" and laying tile. I'll be renting one of the smaller 1' wide bucket diggers do do the excavating. There are several issues/areas I have questions about. I understand the process, and have gotten some good help from an acquaintance who has experience doing this, but several questions remain.

1) I want to tie in and drain my gutters to this whole system which will eject out near the front edge / street side of my property into a small stream. I worry that the gutter water will overwhelm my 6" standard tile that I'm laying and/or that I'll be just bringing extra water into that trench unnecessarily. Would I be better off running solid 4" pipe over or alongside that tile to handle all the gutter runoff?? or am i overthinking this?

2) If I do run a seperate "gutter channel" any suggestions on how I tie all that in to my sump system in terms of ejecting all that water? I really have very, very little slope to deal with and will need to eject that water from the tile line regardless which i'm planning on through the use of an exterior sump pit, with a beefy pump.

3) Other considerations that I might be missing or other help would be great. Thanks in advance. 

Mark


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## pls8xx (May 2, 2009)

Keep the roof water totally separate from all other water and do not allow it to reach a lower elevation than can be piped to the creek/ discharge area.

Maximize the the surface discharge of excess water and keep any piping separate from other piping systems.

Minimize the soil absorption of water near the house with grading and or less permeable materials to reduce the water that will have to be pumped from the subsurface trench.

It would be a big help to you in the design if you had an accurate base map of your property.


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## markeyro (Jan 18, 2011)

*here is the layout...*

The diagram is attached, hopefully it will display, otherwise i'll have to go read a post on how to post...

Anyways, how does this look? I will be ripping out our concrete porch and do not want to rip out our deck, so we'll end the tile lines at the sides of the deck. that works out okay simply because we get decent runoff from under the deck away from the house.

Suggestions? Thoughts?

Thanks,
mark


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## markeyro (Jan 18, 2011)

*along these lines...*

just had a guy out who said that it would be a waste to trench the whole exterior. said the water would still come up through the crawl and that i should put in another sump pit or even 2 if necessary to keep the water pumping out. i guess i kind of get his argument, but i really think that most of the water that's getting in is perimeter water from around our house coming in from the sides, not just bubbling up from the middle of under the house. am i thinking crazy here? any insight or opinions would be welcome...

mark


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## markeyro (Jan 18, 2011)

Anyone out there that can speak into this thread?? It would be really helpful to me. Thanks!
mark


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## pls8xx (May 2, 2009)

markeyro, 

I'm sorry to be so late in getting back to you. I've been really sick the last few days and I'm rather behind in some important duties. I will try to make a response by sometime tomorrow.

James


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## pls8xx (May 2, 2009)

markeyro, 

I commend you on the nice plan drawing you completed. It looks to be a scaled drawing on a 10x10 grid. You are well on your way to the adequate base map needed to complete a design of your project. What now needs to be added is the vertical data. 

There are a number of ways that vertical measurements can be taken. Generally, flat lots require a higher precision in the data than does property with more slope. And there is a wide variety in the equipment and resources available for a particular homeowner to use in acquiring the information. I can better suggest a method for you if you can provide photos of the property.

Concerning the location of the proposed subsurface drain, I suggest it be placed away from the foundation a few feet. The area above the drain and somewhat to the sides will be de-watered as shown with the shading in the graphic below. But the pipe will not remove all of the water from the bottom of the trench. Some water will be dispersed downward from the trench as shown by the blue shading. By placing the drain away from the house this water is kept away from the house foundation.


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## dinah (Apr 16, 2010)

Is your water table high for this area? If all your gutters and downspouts are functioning, and the sloping is away from the house, I'd investigate where the water is coming from before I would do all that work. I'm in KY, but I try to deal with it on the surface. Pipes can eventually fail, then you don't know where your problem is because it's hidden.


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