During the electrical upgrade, several PEHD tubes were laid through a hole in the wall (60cm thick). I am not sure how to fill the hole - want to keep the water and the dirt outside. Insulation is not a requirement, since it is in the basement (c.a. 70-80cm under ground level). I currently do not think that the wall outside will get insulated. It is currently in a dry area, i hope it stays dry, but want to keep it watertight as much as possible.

I was recommended to use well foam to fill the hole. I am rather inclined to use the foam from the inside, and from the ouside use something fluidic, that sets and hardens (e.g. some kind of asphalt/bitumen?). I also want to have it rodent-proof/insect-proof. How to fill the hole?

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  • What's with the looped tube on the exterior?
    – Huesmann
    Dec 4, 2023 at 13:36
  • will be an outlet on the spot (right above the hole) if necessary
    – G. B.
    Dec 4, 2023 at 15:13

2 Answers 2


As a masonry wall, the obvious would be mortar of some sort, injected and packed around and between the tubes. If you want to add a waterproofing layer, do that after the mortar cures.

Given the tight spacing, an epoxy for masonry applications would be the other thing that comes to mind

  • 1
    yeah, one of those caulking gun epoxies could be just the thing here.
    – Jasen
    Dec 5, 2023 at 3:21
  • how would you inject the mortar, so that it stays between the tubes?
    – G. B.
    Dec 5, 2023 at 7:41
  • 1
    As opposed to flowing into the house? You just make your mix not too runny.
    – Huesmann
    Dec 5, 2023 at 13:23

Well, obviously the outside part should be filled with soil, compacted, and capped with concrete/turf. I think I'd throw some flowable concrete/grout at the bottom of the hole first to seal up the wall area where the tubes penetrate.


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