GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Footer drain in high clay soils

Joe Norm| Posted inGeneral Questionson

I’m wondering what the right kind of pipe to use is for a footing drain soils with high clay content?

I’ve only ever used the squiggly pipe with fabric over it but was wondering when people typically would use the hard pipe with holes on one side?

Seems like fabric risks getting clogged pretty fast with fine particles.

Thoughts appreciated

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. Jon R||#1

    Fabric wrapped around gravel will provide way more surface area than a sock over the pipe. But clay will go through any available fabric - so make sure it is easy to clean the drains. And/or use 3-6" of very fine sand as a pre-filter.

  2. Expert Member
    Malcolm Taylor||#2

    Joe,

    灵活的排水管道,(通常称为大O)蜜蜂n supplanted by rigid perforated PVC pipe almost everywhere for a few reasons.

    - With Big O It is hard to maintain a consistent slope, and the pipe can have low points. Both of which make it more difficult to remove standing water.
    - Big O typically relies on twist joints - which in practice rely on the surrounding material to keep the pipe together. That means there is a much higher likelihood of the joints opening, especially if the pipes require mechanical cleaning.

    The only argument I've heard for favouring flexible pipe is cost.

  3. Joe Norm||#3

    Thanks,

    In a footing drain, it is my understanding there would be no slope. Is this correct? How do you orient the holes in the rigid pipe? I have read they should face down toward the soil.

    I am going to do my best to grade the site so water will not make it to the footer at all, but in the case that it does, I'de like this drain to be functional.

    Thanks

    1. Expert Member
      Malcolm Taylor||#4

      Footing drains benefit from a slight slope. They can function fine if they are flat, but flat means flat - with no portion having a negative slope - which is hard to accomplish. What they don't do well with is dips where water and sediment can settle.

      Perforated footing pipes have two rows of holes about 1/3 of the way round the circumference apart. The pipe should be placed so the shorter solid portion in between the rows faces down.

  4. Joe Norm||#5

    Will the footer/soil intersection act as a wall where water will hit, then rise up, hopefully making its way into the drain?

    I am wondering how you would slope a drain pipe like this over any distance? Seems like if you're above the footer at all this pipe will not do its job, but digging it below would be quite labor intensive

    1. Expert Member
      Malcolm Taylor||#6

      Very few excavations are completely flat. Make sure your solid drain leading to the storm sewer or daylight is located at the low point - or have several if necessary.

      We aren't talking about the 1/4" per ft you want on the solid pipe. Just enough to ensure no part of the perforated drain ends up sloping the wrong way.

      1. Joe Norm||#7

        Well, my excavation was within an inch of perfectly flat. And the uphill side of the house has to drain to daylight on the opposite side. Seems like a tall order. I suppose I could daylight in two more locations

        I think the most effective drain will be the curtain drain I plan to install as a first line of defense. This will slope to daylight in two places, hopefully taking care of 95% of the water.

        1. Expert Member
          Malcolm Taylor||#8

          "my excavation was within an inch of perfectly flat"

          Don't worry about a thing. The drains will be fine.

          1. Joe Norm||#9

            Not sure what you mean by this?

            thanks

          2. Expert Member
            Malcolm Taylor||#10

            As I said in post #4, a slight slope may be desirable, but flat is fine. If your excavation is within an inch (hats off to your contractor), just lay the pipes following the grade that is there.

  5. Expert Member
    Peter Yost||#11

    One insurance policy for eventual or maybe inevitable clogging is to install a clean-out for your foundation perimeter drainage system.

    See this previous Q&A string://m.etiketa4.com/question/foundation-drain-tile-and-filter-fabric.

    Peter

  6. Ryan Magladry Ottawa, Ontario||#12

    use a good drainage membrane on the outside of your foundation wall (delta Ms or Platon etc), it should contour over the footing. Lay down an 6' wide roll of filter fabric butting against the footing, and laid flat away from the wall onto the excavation/side slope, socked perforated subdrain around perimeter and plumb to daylight/sewer, or worst case sump pit. Use a stone slinger to place a bit of clear stone onto pipe, slowly lift the subdrain/weeper so that there is 1-2" of stone beneath, ensure it is flat around the foundation, or better yet provide some slope, it is ok if the pipe does not have clear stone beneath it.

    cover pipe with 12" of clear stone , and clear stone 12" up onto footing, overtop of the foundation drain board (delta ms or platon). Cover the clear stone in filter fabric geotextile. backfile. Enjoy a dry basement.

    1. Joe Norm||#13

      a drawing of this would be great

  7. Mike Theis||#14

    大多数时间流失pipe never even gets wet.
    The water collects and travels through the rock to daylight or sump.
    If money is no object than by all means use rigid pipe. I think the time and money of rigid pipe is better spent on more rock and filter fabric. We are better of with well designed and installed flexible pipe than rigid poorly installed rigid.

    1. Expert Member
      Malcolm Taylor||#15

      "We are better of with well designed and installed flexible pipe than rigid poorly installed rigid."

      Sure, but those aren't the only two choices. A properly installed perimeter drain using rigid pvc is the code minimum acceptable here. What to aim at is doing the job properly.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |