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

[rickyb01]

I have to run 220 wiring into a root cellar I have. I will be core boring the 2" hole about 1 foot from the top. The hole will be bored into the side of building that is 8" thick poured concrete. This should eliminate a lot of hydrostatic pressure going up high on the wall. After I core bore the hole I will slide 11/2" PVC sch 40 pipe thru the hole and would like some input on sealing the area between the pvc and concrete to keep any moisture from seeping in. If I use 11/2 PVC the OD is 1.90 inches so I will have a little room. The reason I want to use PVC is I have a lot left over from a project I never did. I'm in the country so no code to speak of. I will spray paint the PVC red so that should alert anybody in the future that may own this home after me of digging.

Two questions: what would be good to apply to the PVC while sliding it in the 2" hole and working it back and forth to hopefully get a good seal?

After I run my electrical wires through the pipe what would be good to seal up the wires inside the PVC pipe? Thanks Rick

 

[sw99]

I had to bore a 4" hole through our 8" thick foundation for the septic. We just used the great stuff foam and never any issues. We did the same thing with our main water line that comes into the house.

 

[LouNY]

I would glue a coupling onto the PVC and then caulk or silicon the pipe before I slid it in that should seal it well and the coupler would act like a small flange.
As far as sealing the wire inside you can get what is commonly called duct seal and pack that in from the outside and spray foam from the inside.

 

[jar06896]

Usually when we drill through a foundation, after the pipe is installed we plug it from both sides with hydraulic cement. Forms a watertight seal. As far as your wiring, outdoors we keep it in conduit until it reaches it's next termination point at a minimum. Inside it depends on the building. Either in conduit until it hits the panel, or we let it exit then run normally through/ along the joists etc. Silicone could seal the end of the pipe around the wiring if needed.

 

[amaxwell]

I have to run 220 wiring into a root cellar I have. I will be core boring the 2" hole about 1 foot from the top. The hole will be bored into the side of building that is 8" thick poured concrete. This should eliminate a lot of hydrostatic pressure going up high on the wall. After I core bore the hole I will slide 11/2" PVC sch 40 pipe thru the hole and would like some input on sealing the area between the pvc and concrete to keep any moisture from seeping in. If I use 11/2 PVC the OD is 1.90 inches so I will have a little room. The reason I want to use PVC is I have a lot left over from a project I never did. I'm in the country so no code to speak of. I will spray paint the PVC red so that should alert anybody in the future that may own this home after me of digging.

Two questions: what would be good to apply to the PVC while sliding it in the 2" hole and working it back and forth to hopefully get a good seal?

After I run my electrical wires through the pipe what would be good to seal up the wires inside the PVC pipe? Thanks Rick

I would use a good 50 year silicone caulk.

 

[rickyb01]

Thanks guys for the comments. The problem with hydro cement (I have some) I don't think you can get the whole 8" with it. You may get the first inch and the last inch because I will have access to both sides. I have a tube of sika waterproof caulk. I think I will lather that tube up with the sika and then install it. Go over the exit on both sides of concrete wall with hydr cement. Thanks also for the duct seal tip.

As soon as the wire comes out of the wall it will be entering my subpanel. I may cut down a coupler to put on the inside as suggested but will not need the full coupler sticking out of wall on the inside.

Would you recommend placing the subpanel over the 2" hole or set the panel off to one side. I would think that thick wire will be hard to work with but would like to keep as neat as possible.

 

[bcp]

Can you use a larger hole or smaller pipe? Probably easier to seal a hole if it is an inch or so larger than the pipe. Don't make a job difficult just to use a leftover piece.

Hardware stores around here sell PVC in cut lengths at 2 ft intervals.

Bruce

 

[RNeumann]

Bad idea to run a short piece of conduit straight into the panel.

Most wouldn’t run a sleeve right into a panel. Full conduit to the other end would be more common.

They make a putty that seals the wire inside the conduit. I haven’t used this brand but your local wholesaler Wil have something similar-

Gardner Bender 1 lb. Plug Duct Seal Compound-DS-11 - The Home Depot

Waterproofing is an entire book in and of itself. You will want to pick a product/system and follow those directions. It would be multiple steps. Caulk, brush on something, apply a sticky, rubbery type product, brush on something else....yada yada yada. Several folks have products. Protecto-Wrap may have some good info online. Your local lumber yard (the ones contractors use- not the box store) would be a good place to start.

 

[triptester]

For a 2" cored hole use 1" or 1 1/4" sleeve. Center the sleeve with rope 2 or 3 inches back from the face of the wall then seal with cement or expanding foam.

 

[rickyb01]

Ok I see the point on not using a sleeve just barely smaller than the hole. I can bore a 2.5" or 3" hole depending on the size of bit my friend has. I don't understand the last post where triptester talks about centering the sleeve with a rope. Is he talking about placing some rope in the bored hole back a couple of inches for the sleeve to sit on? Anyway having a bigger whole which would make my pipe smaller in the whole makes since and it is something I will do.

I understand waterproofing is a book all in itself. I have had this building dug up and sealed from the outside and inside. I also had two French drains placed around the perimeter. About every three months I run a sprayer I made out of 1/2" PVC up the drains to wash them out and keep them from silting in with sand. Thanks Rick