My husband and I just finished installing a drain system in our backyard. Before you even begin, have the utility companies come out and mark their lines and tell you how deep they're buried. We dug ours about 15-18" deep (you need at least this to accommodate the gravel and the pipe diameter and a few inches of dirt on top - alot of people do about 24"). Then we layed down the landscape fabric - use 4 ft and leave the extra width to wrap the rest of the pipe after you finish with the rock. We then layed in about 3-4" of gravel rock (there are different definitions of gravel...we used about golf ball size gravel). Do not use sand...this will just clog the pipe. We then layed the black pipe with the holes all the way around. Water will take the path of least resistance; therefore as the ground becomes saturated, it will seep into the pipe through the little holes. We also used a white fabric sleeve over the pipe to help keep sand and dirt from getting in and clogging the pipe (I figured I'd rather take the extra step now than have to dig the thing up in a coupe of years because it's clogged).

As you lay the pipe, you need to ensure that you have a slope going the direction you want the water to flow (I think we used about 1 inch every 15-20 feet?). We made necessary adjustments by changing the rock level under the pipe (add a few here, take away a few there). We found it easier to start at the drainage end and work backwards up the pipe to get the right level. Once the pipe is set, just cover the rest of the pipe with a few inches of gravel (sides and top), and the rest with your dirt of choice. We did not use the drain boxes that a lot of places suggest. Our run is about 200 feet, but we have various connector points where we tied in our gutters to the drainage system. So if something clogs, we have various points to try to get in to clean it out. Be sure to make some sort of a map and keep it in a safe place, so if you do have problems, you'll know exactly where to dig to fix it, and not have to tear up your whole yard. We have not done anything about covering the end of the pipe yet...I probably wouldn't use the fabric...I would think that it would slow the drainage. They may make some sort of screen for the end.

With yesterday's downpour, we can tell you...it worked! :-) This is a tedious project, and it will probably take longer than you think. It's not difficult...hardest part - shoveling rocks, and getting the slope right. Once we got going it was easy. Rent a trencher/ditch digger. It will save your back!

Other resources: do a google search for installing a french drain, check out the home improvement books at Lowe's & Home Depot, and we actually found a guy who used to do this kind of stuff before he retired at our local HD who worked in the garden center and picked his brain for about 20 minutes (these guys are hard to find...best to go middle of the week when they're not swamped).
Good luck.

Thank-you! Luckily, our slope is already there, the property is already sloped so we are just following that. And I did get good guidance for the basic instillation and needs from a friend on this forum who is a professional. It's just not fair to keep bugging that person when I am not hiring him,lol!

I agree with you about the sand. I'm not sure why it was recommended, so that is why I asked. I'd rather put in gravel. I have no idea what a drain box is. I'll look it up.
The library had a book, but it only has one short paragraph on the drains with no real instructions...just a list of materials and a "slice" photo of how general construction goes. Nothing about grade, or anything else.

THANK YOU,
Girlgroupgirl

GGG,

I can tell you all about drain boxes I just had 2 more put in this week! Yeah! I think they are going to fix many of my problems. the drains are best if you ahve a main piont where the water hits, like coming off the corner of my driveway and my front walkway for example. It is a box that connects to a pipe and is covered with a grate. I now have 3 in my yard. I need to have a french drain put in my daughter's playground area as it is at the bottom of steep slope, so I have read up a bit on those as well. If you can get your hands on a back issue of Backyard Living magazine there was an awesome how to article regarding french drains. I lent it to a neighbor and never got it back. If you would like I can see if she still has it. It was really detailed. this link is pretty good.

Here is a link that might be useful: trench drain

I'm definitely a non-expert on this subject. But I did put in a couple of short french drains by myself and they work great.

Since you have a built-in slope, you only need to dig deep enough to accomodate the pipe and gravel. I have only a couple inches of dirt over mine, with grass on top.

Yes, the pipe you want has holes only on the top and sides, not on the bottom. When you buy your pipe, you should definitely get the white fabric sleeve to go over it. Tie a knot in the end to keep out critters. The water will still flow through with no problem.

Gravel of any size will be fine. You want the water to go from the ground into the air pockets between the gravel, then into the empty pipe.

Re: critters, you don't have to have an "open" end. The beginning end should have a grate over it to keep out debris. The other end can have a grate too - they sell round ones that fit over the end of the pipe. Or, you can have your water dump into a gravel pit. It doesn't have to be huge -just a hole filled with gravel, a couple of feet deep, to allow the water to seep into the ground.

Go for it - it's not that hard. Even if you don't do a textbook-perfect version, it will be a huge improvement in the drainage.

I can manage the small french drains easily next door, that's not as much of an issue as it is getting my own in. Which may need to be put in sooner rather than later.
We have standing water in our heat ducts now, from the storm last night (it had also been moist in there awhile, but worse after last nights rain)....I wish we had a conversations forum here so I could ask more about that (hint hint, someone please email me if they can recommend good HVAC since now I have a large replacement of duct work to do, and SOON!!!!)

I didn't know they made grate ends for the end of the pipes! That is good news. I can use that for french drains that do not die into the gutter system.
Kathy, do the drain boxes fill up with debris like mulch, or do you put them very close to the say, driveway where it is less likely for debis to get in? I have water that runs from my driveway into that area beside the house nextdoor too, so I could really use a drain box and can tie in that line with the french drain line going the other direction, very easily.

Now, my next question would be, what about drain lines that get burried that are run from gutters? I will have some that I want to be placed either under a garden by the deck (which is where the french rains would also eventually go from my house) or come out into a swail around the garden. I'm wondering about gutter debris getting caught into this system. With lots of trees, we can get a lot of debris. Our roof pitch is so steep my hubby and I don't clean the gutters ourselves but have someone do it twice a year. Sometimes I think they could be done 10 times a year, lol!

GGG

GGG the drain boxes need to be in areas where they can be surrounded with either grass, formed concrete or very large stones. Mulch would be a problem. I doubt mulch would clog them, because it is so small it would jsut wash out, mine have 6 inch pipes coming off of them which then connect together to a 10 inch pipe, so that would need to ba lot of mulch to clog them up, and with all the water I get, there is a lot of force clearing them out. But you would have your ,mulch washing away all the time and that would be frustrating. If you don't know what they look like, just think of the storm grates you see set in the middle of parking lots sometimes. I will try and take some pictures of mine if you would like. They are surrounded with grass in my yard. They had to change the shape of one of my beds to avoid mulch getting into one. I jsut ahd a bunch of downspouts piped. I think if you have enough force going through the pipes with all that water, you will not have many problems, but I am no expert.

OK, Kathy, thank you. I should like photos.
I need to place this in the garden, with it's front against the driveway. I can put some larger stones around it, and the mulch won't go down inside of it.

Now, how for those who have done it themselves, how do you calculate how much crushed gravel you need? The rest is easy to figure out, but I'm not sure how to figure out how much gravel is needed. A 10" drain sounds huge (and a lot of digging). I don't think I need one quite that big in this area!!!

GGG

How much gravel do I need above and below the drain. I need to calculate how much I need to buy.

THANKS!
GGG

Just get a cubic yard of crushed gravel. Get it delivered, don't buy tiny bags of it. It's actually cheaper to pay for delivery than to get bags. A cubic yard will keep you busy for awhile, and then you will have an idea of how much more you might need.

Four inches of gravel underneath and on the sides of a four-inch pipe is plenty. As for the debris-in-the-drain problem, I just raised the grate a little. It's not like the water has to flow into the grate. The air space in between the gravel allows the water to seep into the pipe, so you could bury the whole thing if you feel like it. I have a grate in one area only because I let the gutters dump into it. I have another area where the top end is buried.

Regarding your gutters, we had ours covered last fall and it was the best money we've spent in a good while. I can recommend the company we used if you like. You won't have to pay to have your gutters cleaned out again, I promise.

E-mail me if you're interested.

I need some clarification. Do I put the holes down or up when laying the piping? I have read to do it both ways and I am bit confused. Also, gravel goes below, on sides and on top? How much do you put on top prior to covering with fabric?

They make metal grates that connect to the end of the corrugated tubing that will prevent anything larger than say 1/2" getting inside. The entire thing sits in the ground and stays put without anything other than grass holding in place. I'm pretty sure I've seen them at one of the hardware store chains.

The holes in the tubing should be facing down. The idea is that the ground is saturated with water, and of course the water will take the path of least resistance, traveling sideways to the french drain, dripping down through the gravel, and collecting on the bottom. The holes in the pipe pick up the water and move it through the pipe.

There should be quite a bit of gravel on top of the tubing. The gravel should come within a few inches of the surface, so as much moisture as possible can seep down through the gravel.

We have french drains installed on three sides of our house, because there had been moisture seeping into the basement. Because our problem was in the basement, our trenches needed to be deeper. I think they went down about four feet when they dug ours. They really work well.

The website below has lots of links and information about french drains.

Here is a link that might be useful: French Drain Info