I have a field-stone foundation built on top of bedrock. Due to the slop of the bedrock, water collects outside and runs down under the wall. As you can see from the pictures, moisture gets in.

I have a couple ideas for keeping the water away from the foundation (I'm open to more though), but also, is there anything I can do inside? Of course I'm also worried about erosion.

Outside: I was thinking of either french drains that lead the water away, or angle the soil next to the foundation and layer it with stones.

Inside: ?

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  • Is anyone else not able to see the pix?
    – George
    Commented Dec 22, 2019 at 3:18

1 Answer 1


Not sure about inside, maybe damp rid or a dehumidifier. I don't suppose it wouldn't hurt to pack concrete in that gap under the wall/foundation (but you should dig this out from outside first).

The truth is, water coming in must be taken care of from the outside. A picture of the outside might be helpful.

I understand that you are on bedrock, but just to be sure, whatever soil exists outside should be graded away from the house. If that's not possible (or is not helpful) then you need to (dig out the outside and) seal the outside of the foundation. Tar and rubber liners are good for houses built into the side of a mountain. Again, packing concrete in that gap under the wall/foundation would probably be helpful. French drains should be at the foundation level... so that sounds like work (cutting into rock?) for you. If this is in the side of a mountain or hill, a cement patio or sidewalk (sloping away from the house) with a retaining wall for the soil would be the most effective solution (for worst case scenarios).

enter image description here

  • I'm positive I can slope the surface so the water will run off into the driveway. What types of materials should I use? I was thinking of laying a large tarp down, throwing down some dirt on that then patio stones and maybe fill in the gaps with small rocks. Or am I way off base?
    – user44111
    Commented Apr 12, 2016 at 23:38
  • Can you also provide a link to the kind of tar used for this (Home Depot or Lowes)
    – user44111
    Commented Apr 13, 2016 at 0:44
  • @Quirk Regarding the tarp (plus rocks and dirt), it would be way more effective (long term) to use a rubber sheet and concrete. I'm sorry, but I can't gauge the situation very well from my computer. Regarding tar, foundation and roofing tar are basically the same; some tars can be applied cold, which may be helpful. Apply tar 1.5mm thick (or as directed on the label). Rubber should be 60 mils (also 1.5mm) or thicker. I would avoid "liquid" and/or "sheet membranes" which are (usually) tar and rubber mixed because they need to be more precise (like for cinderblock - not for rock-rock). Commented Apr 13, 2016 at 12:59
  • @Quirk 45 mil rubber liner seems to be commonly available as small pond liners. 60 mil rubber sheets are considered roofing material. Commented Apr 13, 2016 at 13:18
  • @Quirk Afterthought: to be clear, I mean asphalt or coal tar (not pine). Coal tar is better. The rubber should just stick to it, but if you have difficulty (like if you had to wait a few days or something, and the tar lost it's tack), then you can probably heat the tar with a hair dryer (until it becomes tacky); heating and applying/pressing the rubber onto the wall in small sections. Or it might work to apply a little more tar to the rubber sheet and then press it to the wall. I don't think you will have any problems, but I wanted to add this just in case. Backfill will hold it after that. Commented Apr 13, 2016 at 13:38

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