I need some expert advice here. I inherited a house that has a pool and a shed. The electric to both the pool and shed pass through the foundation of the house underground through what looks like PVC conduit. I recently noticed that the conduit, where the wires protrude, is leaking water. I haven't noticed this all summer but now that the winter is here and the ground is frozen, water is finding a way into this conduit.

I have a temporary solution to capture the water into a plastic tote using a make-shift gutter down spout extension that is catching the water and storing it in the tote so it doesn't make a mess in the basement. The conduit extends about 3" to 4" on the inside of the basement wall, so wrapping a sock around it and catching with the spout extension into a tote seems to work and not make a mess. However, I'm looking to permanently fix this issue, most likely in the spring.

So, if I dig up where I think the wires and conduit enter through the foundation, I would like some idea on how I can patch this hole. I've read about a myriad of solutions and one being hydraulic cement. My research says that the hole needs to be very clean and lightly damp for the cement to make the best bond.

For a more permanent solution I want to remove the pvc and conduit from the hole in the foundation, clean it up and patch it in the late spring. My concern is that this size hole is too big for hydraulic cement, but my inexperienced mind just tells me that. Can anyone just provide me with some knowledge and experience and let me know what the right solution is, if it is hydraulic cement and what else I should know and or do for preparing the application of it?

Thanks for your help!

  • Is the water entering through the conduit, or through the hole in the foundation and running down the outside of the conduit?
    – brhans
    Jan 18, 2017 at 19:53
  • No it appears as though the water is coming in from the conduit. There didn't appear to be any water flowing in from between the pvc conduit and the foundation wall. That looks like it's sealed up with some kind of clear silicone. I came home tonight and the plastic tote had about an inch of water in it but floor was dry. So it's coming throw the pvc where the wires were pulled through. I cut off all power the other night to the shed, which doesn't get any use in the winter anyways. I'm hoping to remove the wires and pvc in the late spring and patch that hole in the foundation with something.
    – DIYSteve
    Jan 19, 2017 at 2:53

2 Answers 2


If the water is running through the conduit foam or duct seal would serve you better than cement. Duct seal has the advantage of not hardening, which should minimize the bill and foul language if you need an electrician to pull a new wire down the road. Then again, I'm not an electrician so there may be a better mousetrap.

To answer your original question "hydraulic cement" generally refers to products with a very short dry time that can be used in wet conditions. (Or under water) In addition they generally expand while they cure, as opposed to Portland cement which shrinks slightly. That's the big selling point for foundation work because it means there's no way for ground moisture to seep around the patch.

The rationale for slight dampness is twofold. Masonry absorbs water, which complicates repairs. If you don't dampen the existing work it can draw water out of the new work and weakens it along the bond. In addition, products based on Portland cement requires ample water to cure but cure very weak if there's too much water. Generally that involves lightly spritzing the surface periodically during the cure so that it remains damp without standing water. Both are less of an issue with hydraulic cement simply because you wouldn't be paying the premium for it unless you were already working in a damp area.

  • Duct seal is the ticket for water inside the conduit. Expanding foam is NOT a good idea.
    – Ecnerwal
    Jan 19, 2017 at 2:13
  • A good amount of water seemed to flow through that conduit filling a large plastic tote a couple inches. Although duck seal may help temporarily, I'm more interested in a long term solution, in case I decide to sell the house in a few years. Maybe I can try that for now until I repair this problem permanently in the spring. Although that water will continue to remain in the conduit, which could possibly freeze and crack.
    – DIYSteve
    Jan 19, 2017 at 2:57

I'd squirt some of that expanding urethane foam insulation into the conduit. Cheap and easy. The other thing to consider is reducing the water available on the outside to leak in. Do you have gutters to carry water away from the house? Does the ground near this problem have a good slope away from the house? If you decide to dig it up on the exterior, a gravel pit & channel leading away from this location could help as well.

  • Yea gutters all around house that carry water away. However this area where the electric enters the house through the foundation sits under a flower bed where there seems to be some build up of water from the deluge of rain we had the last few days. There is a bit of a slope, but I like the idea of some gravel and channels. I may have to do that this spring also.
    – DIYSteve
    Jan 19, 2017 at 3:00

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