[sdemas]

I need help. I'm getting conflicting information regarding French drains.

I have a house that's having drainage problems.

1. No gutters (they are being installed on Tuesday)
2. Ground level was higher then floor level (YEP that's right... we've managed to bring the ground level down now though.)

There was an existing french drain in the front of the property, but now I'm being told I need it around the entire house. The trenches are dug and ready. But I'm having problems figuring if I need corrugated or pvc pipe.

I've had different people tell me different things and all my research online has left me baffled.
The plan is to back fill the trenches with gravel leaving a "rock garden" around the house, which will be outlined with landscaping ties. And I plan to place flower pots around for decoration. So I don't expect this area to have high traffic. The trench will also be lined with heavy duty plastic to prevent weeds etc (is this ok as well?)
the existing drain ties into a pipe that runs out into the ditch and we are planning to use a similar scenario on the other side of the house. So there will be parallel lines running away from the house on both sides of the gravel driveway.
My questions:
1. Do I use PVC or corrugated pipe?
2. Would it be ok to use corrugated pipe around the house? and use pvc to run to the ditch?
3. Should I tie the gutter downspouts into the drain or just run them into the trench?


I have about 4 people telling me different things and it's driving me crazy.. Any input you can provide would be greatly appreciated.

[Greensmith]

There really shouldn't be conflicting info there. PVC is the best bet for high traffic areas and longevity. If you tie the gutters into the drain system make sure you have a sediment trap in the tie in before the runoff gets sent deep into any drainage systems or you will be digging it up in 4 years.

Corrugated is a temporary solution in most cases unless you need the flexibility (obstructions) and don't feel like cutting and gluing multiple angles. The downside to this is that sediment tends to collect at hard angle turns and will eventually impede water flow.

[Stonehenge]

I know they use corrugated to collect water around the foundations here, but in an area where the pipe will see a lot of weight, many brands of corrugated will crush pretty easily, leaving you with almost no ability to move water.

As for the downspouts - your goal here is to keep the water away from the foundation, so running the eaves down to this system will tax it more than it needs to be taxed.

Some other thoughts - you might want to cap your 'rock garden' around your house with some clay. Most water landing from above will drain away from the house (when graded correctly) over the clay. Open stone seems like an invitation to water.

[jshilan]

I would use the perforated PVC around the house (as per Stonehenge) and solid PVC for the downspouts and absolutely "DO NOT" tie them together. They can be run in the same trench but should definately not be connected to each other. If somehow the drains got clogged, the water would back up to the foundation and back into the house. If you are adding all of the water volume from the roof to this situation. you'd better get some wading boots and the heavy duty wet/dry vac.

blub, blub

[Fine Edge]

I agree - perforated for any foundation drain but do not tie the downspouts into them.
Downspouts can be either solid PVC or double ( smooth ) wall corrugated. We've had good luck with the double wall and it is very strong ( more $$ of course ) but not flexible.
Oh, and don't use any plastic. There are other products out there designed specifically to keep any soil out of the perforated pipe. And please use plenty of gravel around and above your foundation drain.

[Honeybee Texas]

Originally Posted by Stonehenge

Some other thoughts - you might want to cap your 'rock garden' around your house with some clay. Most water landing from above will drain away from the house (when graded correctly) over the clay. Open stone seems like an invitation to water.

This has all been great info, and I appreciate it. My question though is to Stonehenge: Can you illustrate this somehow? I'm trying to picture putting clay on rocks and I'm not getting it. Like, clay mortar between 6" river rock or something?