Don's Home Home & Garden French Drain

• Pipe - Most people use 4 inch corrigated perforated pipe, which has holes all the way around.
  Solid PVC pipe only has holes on one side which should be at the bottom requiring stone under the pipe. This leaves water in the stone which invites tree tree roots in. Corrugated pipe has holes all the way around.
  You would think water would flow better in solid pipe but the Frrench Drain Man says "The corrugated pipe causes turbulence and more pounds per-square inch."
  If holes are on 1 side only put them on the bottom so the water will start filling the pipe before before the trench is full.
• Stone - Use a clean natural 1½ round stone (Ace calles it "river drain"". Avoid Crushed Rock (minus) that compacts and has "fines" that will clog pipe inlets.
• Fabric - Use 4 - 8 ounce ounce non-woven geotextile filter fabric (Home depot calles it Septic Fabric or Soil separater Trench Fabric)
  You may have to fasten the fabric at the top to keep it from being pulled down when you add the stone.
• Rain Downspouts - Running a rain gutter downspout into a drain pipe can be a problem because of debris clogging the drain.
  A solution is to add a catch basin which can be cleaned out.
  You can even get catch basins with removable mesh filters
  and Downspout Cleanout Leaf Filter

1. Check for underground utilities in the path.
   
2. Plan flow preferably to a point that is lower than the area to be drained.
   Otherwise you may have to put a sump at the end to hold the water or pump it out.
   Mimimum slope for solid pipe is 1% (1 inch per 8 ft) 2% (2" per 8') for corrugated pipe. 3% is best.
3. Dig - The trench should be about 18 inches deep and 9 to 12 inches wide.
   consider a trencher rental to get your project done.
4. Line the trench with fabric. Leave the filter fabric open with at least 10 inches of excess fabric at the sides to wrap over the top.
   
5. Pipe and Gravel - There are 2 ways to do this:
   a. Gravel around the pipe, bottom, top and sides. b. Pipe on the bottom with gravel on the sides and top.
   The Frrench Drain Man recommends b with the pipe on the bottom, so you don't have excess water below the pipe which can attract roots from trees which can eventually get into the pipe and clog it.

Problems: (clogged drains)

Solutions:

• Minimize standing water which will attract tree roots by putting the pipe directly on the bottom and avoiding dips in the line.
• Chemicals that stop root growth without harming the tree or soil.
  
  • Pour RoutX in the drain
• There are sewer cleaners that are larger than a typical rotorooter. Over 50 gpm at 3500 psi does a good job on roots. Finding one that is affordable may be a difficult task. You may have a local company that cleans drain tile lines for farm fields that could do the job.

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  Links:
  
  7 Common French Drain Mistakes & How to Avoid Them | ProFabricSupply
  PVC Pipe vs Corrugated Perforated Pipe | FrrenchDrainMan.com
  

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