drilling 2" hole through poured concrete wall how to seal?

[triptester]

Without something to hold the sleeve centered in the hole it will have a tendency to settle to the bottom while trying to seal.

 

[ray66v]

Do not rely on silicone calk. It is not good for a permanent bond, with concrete.

First choice is, as stated previously, hydraulic cement. Guaranteed lifetime seal.

Second choice is, urethane calk. See the concrete department in the big box store. They sell all the different calks for concrete there. Note, there will be no silicone there. Urethane will also last forever. Provided you get the concrete completely clean, and dry, before you apply it. Compressed air is ideal for this.

 

[PILOON]

I vote for the urethane caulk*, use that stuff all the time, my goto for many projects, like WD40 is my other goto and duct tape.

I use it just like glue, try to pull apart anything 'glued' with urethane caulk!
Also great as a thread sealant on pipe thread joints like in hydraulic fittings.

 

[D2Cat]

Don't be concerned about drilling the hole large enough to have a sealer the full width of the wall. Drill your hole, install the conduit. Scrape the opening of both sides of the concrete with a flat screw driver to form a bevel. Mix hydraulic cement about the consistency of Mayonnaise and work back in the area with your hands. Do the same on the outside. Hydraulic cement expands and will not leak.

The conduit you have outside above grade should be schedule 80. Code in most areas. But important to protect it for abuse like a ridding lawn mower.

 

[buckeyefarmer]

I put 10 holes thru my 8" wall. I used hydraulic cement outside and some of them inside. no leaks in 7-8 yrs, even the ones I never finished sealing on the inside.

 

[Ford850]

If the underground conduit running to the wall is sloped down, running from a higher grade, be aware it can act as a tile. If the conduit has a weak joint, water can enter it a great distance from the wall and run down the conduit creating pressure that's hard to stop. I had a case where water filled the LB on the inside of the wall, and above that a couple feet in the 2" conduit. The LB cover seal was the weak point and would seep water for days. I solved it by drilling and tapping the bottom of the LB, threading in a small brass barbed fitting, and adding clear tubing to the fitting that I ran back out through the wall and into the footer tile area. I could not access the outside easily so that was my easiest solution. Had I planned for this issue, I would have a trap or drain of sorts in the conduit outside the wall in case of a fitting that leaked.

 

[EddieWalker]

Once the conduit is in place where you want it, I would use a concrete sealer type of caulking. I would not use regular caulking or silicone. The concrete stuff sticks to concrete better then anything else. Next on my list of choices would be flashing sealer from the roofing department.

 

[rickyb01]

If the underground conduit running to the wall is sloped down, running from a higher grade, be aware it can act as a tile. If the conduit has a weak joint, water can enter it a great distance from the wall and run down the conduit creating pressure that's hard to stop. I had a case where water filled the LB on the inside of the wall, and above that a couple feet in the 2" conduit. The LB cover seal was the weak point and would seep water for days. I solved it by drilling and tapping the bottom of the LB, threading in a small brass barbed fitting, and adding clear tubing to the fitting that I ran back out through the wall and into the footer tile area. I could not access the outside easily so that was my easiest solution. Had I planned for this issue, I would have a trap or drain of sorts in the conduit outside the wall in case of a fitting that leaked.

What are you calling the LB. I have also thought about the conduit bringing in water to the building which is why I have decidied against putting my subpanel right at the exit of conduit. Could you expand more on the trap or drain you would do before bringing it in the building.

 

[cat fever]

After years of mine leaking. (hole in the foundation) I foamed it and it's never leaked since.

 

[chim]

If the underground conduit running to the wall is sloped down, running from a higher grade, be aware it can act as a tile. If the conduit has a weak joint, water can enter it a great distance from the wall and run down the conduit .....................

Water will find a way into buried conduit. Running the conduit directly into the back of the box could end up draining water into the box from the buried conduit. I've seen specifications requiring buried conduits to slope away from buildings.

Hydro cement and expanding foam would probably be fine to seal around the conduit. Here's what we usually use on projects to seal around pipe penetrations in poured walls:

LINK-SEAL(R) | GPT Industries

I'd be just as concerned about water coming through the conduit.