Asked on May 15, 2014

Basement Drain pipe connected to a French drain?

Kathy Dillard
by Kathy Dillard
Hi i recently bought a 40 year old home and our basement laundry sink was always clogging up so we dug up the basement drain pipe from outside and found out it was connected to a white PVC pipe with holes "French Drain" i believe there were lots of gravel and landscaping fabric around.
When we cleaned out the pipe there were lots of greasy sludge and sewage smell because our upstairs kitchen sink is connected to the basement drain, Before I cover things up do you think this is a good way of draining water away and hoping it never clogs up again? or is there a better method.
  5 answers
  • Moxie Moxie on May 16, 2014
    If you had an FHA loan/and inspection and purchased the home with the understanding the home was up to code you may have grounds to seek restitution from the previous Owner. This drain type would not be considered in accordance with code anywhere that I know of in the US because chemical contaminants from the sink drain can get into the ground/water table. This line should be hooked up to drain to a sanitary line (city utilities) or leach bed system; whichever you have. To keep it quite, the alternative may be to add some clean out fittings to the line so you can maintain the line clear without digging it up.
  • all gray water needs to be sent to the septic or sewer system. Only clean fresh ground water is allowed to drain into the floor pipe water control system. Dig out the pipes, replace them around the edge of the basement as they most likely now are fully plugged with grease and lint from washing machine. Not doing so will cause your interior water control system to fail. Install proper pump system if necessary and drain to sanitary drain as required in your area.
    • See 1 previous
    • @Kathy Dillard You can only connect to the septic if the drain line is higher than the tank inlet pipe. If its not, you need to install a pump unit which is much like a sump pump that is designed to pump the water up high enough to allow it to properly flow. If your future plans has anything to do with black water (sewage) then get a sewage pump installed into the floor and have it professionally connected to the drain system.
  • Kathy Dillard Kathy Dillard on May 16, 2014
    Thank you for your replies i was thinking the same thing when we dug it out it just didn't seem right. I live in a rural area so the only system we have is a septic tank which is connected to all wash rooms, but then that drain is in the other end of the home. I might have to have a talk with the home inspector he said everything was connected to the septic tank and in working order.
    • Shelly Martin Damico Shelly Martin Damico on Jun 07, 2018

      Hi Kathy, is it a septic system or a cesspool? They are all correct with gray water needing to be sent to the sewer line, but that may be what they did by sending it to the cesspool/leach area. Cast iron pipes are most most commonly used to with stand ground elements. I also agree that it the plumbing was improperly connected your home inspector should have made it know to you at that time. I am actually here looking for help with my dilemma, I too have a musty smell that is in my back room only, it just started about 2 weeks ago and I think it's getting worse. I have a sump pump in my basement that is connected directly to a french drain that forces the water up through pvc pipes that run though my garage and then it goes outside into a french drain that runs under a very large pine with very big roots, and is supposed to exit at the end of the stone wall. I checked the exit and it's only rocks/dirt and very dry. I tried to look inside and it appears clogged. I believe the tree roots have strangled the pipe so I started digging the pipe up at the foundation and it seems fine so far. I realize it's clogging somewhere with in the line but it isn't close to the house, so now I wonder is that the cause? I also had a new roof installed almost a year ago and now I am wondering if the musty smell is due to poor or lack of flashing work done around my chimney. If anyone is able to help me figure this out or suggest a 3rd possibility or suggestions maybe?

  • BDry Waterproofing BDry Waterproofing on May 16, 2014
    I would agree with Woodbridge Environmental, the system need to be replaced. If the current system is not working properly you can end up with water in your basement.
  • Neal Brady Neal Brady on May 16, 2014
    You should have a trap in your basement just before the sewer water goes through your foundation. Make sure your trap has a clean out on it. Once your outside your house the French drains can connect into your sewer lines (Depending on your town/city ordinances). and because of the trap in your house the water in the French drain should not back up into the house. Inside the house you should have a 3 or 4 inch pipe which goes to the trap. The kitchen sink and laundry sink should feed into that pipe separately. so unless there is a backup in the sewer line outside your house the house sewer water should not be an issue. Since a kitchen sink pip is 1 1/2 inch and you are connecting it to a 3 or 4 inch pipe there should be no need to worry about any grease back-up. You can pour some Riad-X down the drain and then use hot water behind it. Raid-X is made to ad bacteria to septic systems. even if you don't have septic it will eat the grease and deposits on your sewer lines. Do you have any tree roots growing into the sewer line?