# Help with drainage problem.



## weatheredwood (Aug 9, 2007)

Can someone tell me if I am supposed to slope underground drainage pipe? Can I just run it level all the way across?


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## raam (Feb 11, 2008)

Yes you do need to slope the pipe, otherwise how will the water get to the trench. I would slightly slope the pavers too, but if you prepare the ground underneath with a sand bed on sloped undisturbed soil or geotextile fabric, the water will permeate through and make it's way to the grill as well. Bump for more opinions.


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## terri_and_jj (Feb 24, 2008)

pipe needs to be sloped. 1/4" per foot is a general rule of thumb for any drain pipe

I'm a little confused. are the pavers already down? what did you use for a subbase and how thick is it?


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## Bondo (Dec 8, 2007)

> I'm a little confused. are the pavers already down?


Ayuh,...
And,..
Which way do the Pavers Slope/ Pitch,..??


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## weatheredwood (Aug 9, 2007)

The problem I am having is that the trench is around 35 to 40 feet away from the first drain grill. The trench is only 6 to 8 inches deep. I can't really dig the trench deeper because of liability issues. I don't want my neighbor kid breaking his leg in the trench while playing. At 1/4in drop for every foot, I am looking at 10inches at the trench. This doesn't include the 3 or 4 inches under grade that it states off at. I would be looking at a trench at a minimum of 14inches. I thought it would drain if at level because the entire pipe is below grade. It would have to drain if it fills with water. 

I haven't laid the patio blocks yet.


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## terri_and_jj (Feb 24, 2008)

is there a reason you can't simply slope the pavers slightly, so the runoff is directed toward the trench?

water is lazy, if you don't slope the pipe, it isn't going to move.


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## raam (Feb 11, 2008)

weatheredwood said:


> The problem I am having is that the trench is around 35 to 40 feet away from the first drain grill. The trench is only 6 to 8 inches deep. I can't really dig the trench deeper because of liability issues. I don't want my neighbor kid breaking his leg in the trench while playing. At 1/4in drop for every foot, I am looking at 10inches at the trench. This doesn't include the 3 or 4 inches under grade that it states off at. I would be looking at a trench at a minimum of 14inches. I thought it would drain if at level because the entire pipe is below grade. It would have to drain if it fills with water.
> 
> I haven't laid the patio blocks yet.


Can you not dig out the trench, lay the piping and then back fill with gravel afterwards. You need that depth.


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## Bondo (Dec 8, 2007)

> I haven't laid the patio blocks yet.


Ayuh,....

In That Case,.....
Alter the grade of what you have,+ pitch the water where you want it to go........
Raise the center of the courtyard, 1 end or the other,..??
Whatever it takes....

What's the Total vertical Drop from the existing Sidewalk, down to the Trench,..??


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## weatheredwood (Aug 9, 2007)

I can't bury the pipe at the trench because the trench leads to the street. It would create a huge trap. I attached another picture. The water would have to drain because it will take the path of least resistance which is out the other end at the trench. I could have problems with stagnant water though. I can't really slope the patio away because there is a structure on either side. If I slope it to the trench, I will have a huge puddle in the yard every time it rains. The trench goes another 25 to 30 feet to the road. The first picture isn't to scale. The trench isn't that close to the building.


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## so-elitecrete (Oct 27, 2007)

*can you break the curb ? ? ?*

leader drains regularly drain onto streets.


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## weatheredwood (Aug 9, 2007)

Bondo said:


> Ayuh,....
> 
> In That Case,.....
> Alter the grade of what you have,+ pitch the water where you want it to go........
> ...


How do I measure the drop? I was going to just pull some string across (sidewalk and trench). I would then put a level on the string and see what the difference is at the trench. Is this the right way? Also, How much should I slope the pavers to the center where the drain is? Is 1 in every 10 ft sufficient?


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## LawnGuyLandSparky (Nov 18, 2007)

weatheredwood said:


> I can't bury the pipe at the trench because the trench leads to the street. It would create a huge trap. I attached another picture. The water would have to drain because it will take the path of least resistance which is out the other end at the trench. I could have problems with stagnant water though. I can't really slope the patio away because there is a structure on either side. If I slope it to the trench, I will have a huge puddle in the yard every time it rains. The trench goes another 25 to 30 feet to the road. The first picture isn't to scale. The trench isn't that close to the building.


Are you saying that AFTER you dig a trench, you're going to leave it open?


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## weatheredwood (Aug 9, 2007)

LawnGuyLandSparky said:


> Are you saying that AFTER you dig a trench, you're going to leave it open?


I am referring to the gully in between the property line. It is common to see them in this neighborhood. It is a very shallow gully because I get worried someone will break their leg.


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## Bondo (Dec 8, 2007)

> How do I measure the drop?


Ayuh,... A Sight Level is the Best,+ Easiest way......


> Also, How much should I slope the pavers to the center where the drain is? Is 1 in every 10 ft sufficient?


As long as it's negative pitch All the way,....
Ayuh,... It'll drain......

Any Pitch, that's less than Dead Level will drain,.... How Fast is the only difference.....


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## terri_and_jj (Feb 24, 2008)

Bondo said:


> Any Pitch, that's less than Dead Level will drain,.... How Fast is the only difference.....


Yes and No. 

It's true If you have a very minor slope, the water will move, but moves slowly

But too slow allows debris to collect and cause blockage. You need enough slope to move water somewhat rapid, so you keep the drain clear or debris


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## Bondo (Dec 8, 2007)

terri_and_jj said:


> Yes and No.
> 
> It's true If you have a very minor slope, the water will move, but moves slowly
> 
> But too slow allows debris to collect and cause blockage. You need enough slope to move water somewhat rapid, so you keep the drain clear or debris


Ayuh,....

If this was the drainage Pipe we're talking about, I'd Agree 100%....
But,...
That statement is in answering his question about the actual Patio Surface....
I gotta believe that if Debris collects,.... He'll be Sweeping it Off......


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## terri_and_jj (Feb 24, 2008)

Bondo said:


> That statement is in answering his question about the actual Patio Surface....
> I gotta believe that if Debris collects,.... He'll be Sweeping it Off......


You Sir, are correct. my bad. 

Although if he can slope the patio about 45 degrees he will probably never have to sweep it at all ( but he may want to take the wheels off the gas grill first):laughing:


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## Bondo (Dec 8, 2007)

> Although if he can slope the patio about 45 degrees he will probably never have to sweep it at all


Ayuh,.......

Actually,..... My thinking is,....
If there's enough fall from the existing,+ unmovable points,...
To the Trench,....
He shouldn't need Any drainage piping at All......


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## tiny (Mar 22, 2008)

Just dig a dry well and be done with it!!


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## weatheredwood (Aug 9, 2007)

tiny said:


> Just dig a dry well and be done with it!!


I don't think a dry well will cut it. Too much water falls off the roof into this area. Gutters are out of the question because they clog up too much. I'm going with a slight slope on the drain line. It has to drain. Even a trap will drain at dead level if the inlet is higher than the outlet. I can't slope the patio towards the patio because it will flood my yard. I already have a flooding problem in that area.


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## Mr Chips (Mar 23, 2008)

could you solve this problem by digging an extra deep base, filling most with compacted fine stone, then a thin layer of compacted sand, and setting the patio block on this. that way the water goes downbelow the surface and dissapates that way. kinda like a dry well under the patio


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## weatheredwood (Aug 9, 2007)

Mr Chips said:


> could you solve this problem by digging an extra deep base, filling most with compacted fine stone, then a thin layer of compacted sand, and setting the patio block on this. that way the water goes downbelow the surface and dissapates that way. kinda like a dry well under the patio



Thanks for the reply. The only problem is that I live in Florida and we have a lot of clay in my area. It hasn't rained in about a week a half and the ground is still wet when I dig about a foot and a half down. I'm worried about the foundation of the structures. I would rather get the water out of there. The pipe is going to be pretty low by the time it hits the gully. I might have to dig a swale instead.


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## Randell Tarin (Jan 19, 2008)

Why don't you consider a French Drain. The slope will all be subterranean and therefore avoid the "trap" you would create by an obvious above-ground trench. I placed one at the base of a stone retaining wall that runs up-hill from my patio.

You will need to exacvate the slope as indicated, but the backfill the trench with course (1"-2" or larger) gravel. With a good base in the bottom of the trench you lay a perforated pipe wrapped in landscape fabric. This pipe should be sloped. Cover the wrapped pipe with more gravel. On top of this, lay another layer of fabric. You can re-place your stone on a bed of sand. The water will permeate the sand, filter through the gravel and into the perforated pipe and out.

This worked for me. I live in East Texas with a sand, red-clay mix. 

Water is going to go where it wants to go. It will always seek the lowest point. You just have to be a little bit smarter.


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## weatheredwood (Aug 9, 2007)

It ended up being really deep at the gully. I only sloped the pipe a half inch for every 5 feet. I couldn't dig a swale, so I decided to run the pipe to the road. It was an additional 45 feet of pipe. I couldn't run the last 45 feet with any slope at all. I just left it completely level. It drains perfectly fine. I tried to inundate it to no avail. I poured a few 5 gallon buckets of water down the main basin and had a garden hose tied to another inlet.


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## call811beforeyoudig (Apr 22, 2008)

Did you know that if you forget to get the underground utility lines marked before digging, it could cost you? For any project that requires digging, like creating a drainage system or installing a fence, call 811 before you start, or visit our website, http://www.call811.com/ for state specific info.


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