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

French drain

Dave Mac | Posted in General Questions on


I had a question about the gap at the wall with the french drain. We are concerned about radon, and if we do not anticipate any water entering the basement again after install of the drain, can we not have this gap at the wall?
Can this simply be cemented over? Contractor said it could.

Also, a local contractor stated he would not need to dig any laterals as the water under slab would find it’s way to the perimeter stone/pipe. Stated, water comes in from under the foundation, and then to the stone trench. Even though my basement is small, 80 linear feet, and there is no stone under my slab, he stated the drain would handle it. This company is local and been around for 70 years, hundreds of references.. no money up front, guaranteed.

Said they dont need to pitch the pipe either. Said it simply works.

Any thoughts?



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.


  1. GBA Editor
    Martin Holladay | | #1

    There are many variables, but in general, your contractor is right. Footing drains and French drains are often installed dead level; of course, at one point in the drain, there must be a connection to an unperforated pipe that connects the perforated pipe to daylight or a drywell.

    As long as you don't anticipate any water dribbling down the interior side of your basement walls, there is no reason that you can't cover your interior French drain with concrete.

    For more information, see:

    All About Radon

    How to Install a Foundation Drain

  2. Dave Mac | | #2

    Thank you.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |