Seal Abandoned Pipe Through Wall Underground: What's A Good Plan?

[PJB12]

Hi All!
I have (had) a manual backwater valve under the driveway between the building drain & the sewer. It had to be removed.
Left behind is a 1-1/2" schedule 40 steel pipe that passes through the basement wall. It had the operating wheel on the basement end and the valve on the other end. Inside is a 1/2" steel rod that the wheel operated.

I can't remove the pipe. I'd like to seal it and the penetration through the concrete block wall against water, rodents and insects. (The blocks are 120+ year old concrete blocks, as opposed to cinder blocks.)

Using materials that I can get locally, my plan is:
Cut the pipe and the rod inside a few inches from the wall outside.
Plug the outside end of the pipe with hydraulic cement.
Cap it with a Fernco test cap.
Clean the block around the pipe with a wire brush.
Use PL Urethane caulk around the pipe to seal to the block wall. (Vulkem isn't available locally, thus PL)
Use roofing tar over the urethane because I have to tar a few feet around as the old tar came off during excavating. The clay stuck to the tar.

The scary factor is that I won't be able to go back for repairs in the future because it will be under pavement.

Is there a better way?
How do you guys handle this?

Thanks For Helping!
Paul

 

[Snoonyb]

Well, were it I, I would cut it back more than a few ", to allow sufficient work space, then wash the block penetration after cleaning, then allow sufficient time for the cement to dry, after which I would attach a fiberglass mesh and then coat with PL, overlapping to the cleaned block and after the driveway is poured and set, use PL to seal the driveway to block joint.

 

[PJB12]

Well, were it I, I would cut it back more than a few ", to allow sufficient work space, then wash the block penetration after cleaning, then allow sufficient time for the cement to dry, after which I would attach a fiberglass mesh and then coat with PL, overlapping to the cleaned block and after the driveway is poured and set, use PL to seal the driveway to block joint.

Thanks for this good information, Snoonyb. I'll do exactly that to seal the sleeve to the wall. I remember in the way back days that we'd put mesh cloth over clay-to-cast joints, then trowel on the mortar. I forgot all about the mesh until you mentioned it. I'll surely use it on this job.

For the inside of the pipe, I think I'll pack it with clay, shoving it back a few inches from the end (since there is a mountain of it after the excavation).
Then, I'll use hydraulic cement to plug the pipe sleeve against rodents, insects and water. I'll end it flush with the cut end of the pipe. The clay pack is to act as a wall when I shove the hot cement into the pipe.
Next, I'll put a Fernco cap for insurance. Does this sound OK?

 

[Snoonyb]

Sounds like a plan.Isn't homeownership just the cat's PJ's.

 

[PJB12]

Sounds like a plan.Isn't homeownership just the cat's PJ's.

At the very least, I never run out of stuff to deal with around here. My life's ambition is to one day be able to say "I'm bored."



This sewer job is a bit aggravating (putting it mildly).
Leaving out a bunch of boring details, essentially the sewer warranty company decided my sewer was broken. After "locating" the break in 4 different by many feet places on 4 tries, the excavator operator chose a place to dig.

There was no break, just the backwater valve mentioned in Post #1. It got damaged, so it had to be removed. (OK with me)
The camera was sent back in. The compromised areas can not be spotted because too many roots are in the pipe.

The company won't send a snake or jet because & camera to find the break because the water still flows. Oh heck no- Fighting this will be Monday's task.

Bottom line so far is that I lost about 100 ft. sq ft of driveway, have dozens and dozens of chips in the other control joints in the driveway, bucket scrape scratches all over the place. And, a mountain of clay blocking access. (Today's project = Me + Shovel)


The very unfortunate parts are-
A) We gained nothing. No improvement. No repair and
B) The concrete was custom, from sub-base to base, to product to bar and mesh. Even the flatwork guy was
specially chosen. Not a mark on it after about 30 years. Not a mark! (I used to tow large generators up to 25,000 pounds + haul cables and panels, thus the airline spec drive.)
There is no way the warranty company will agree to put it back to spec. This will be out-of-pocket to get it correctly done.

Sorry to complain, but I thought the driveway-sewer thing fit perfectly in your "Cats PJs" comment! Perfect!

 

[PJB12]

Procedure Change-
I found that the block through which the pipe sleeve passes is cracked under the sleeve & a chunk is missing. I can't get good access due to the pipe angle. So, the decision was made to remove the pipe. Not so lucky.

The sleeve is dead-stuck in the block. More than likely many decades of weight on the wall pinched it or the cement based product that the installer used is very strong.

The latest plan is to cut the pipe off flush with the block, indoors and out. Seal the pipe ends with hydraulic cement, lapping perhaps 1/8" thick onto the block walls. I may even drill some holes in the block around the pipe so the huydraulic cement has a grabbing place. (Not sure if that is smart or detrimental)

When the cement cures for a day, I'll do as Snoonyb suggested with the PL sealant embedding the mesh tape that he wisely suggested.

If rain's not forecast, I'll let the cement cure longer. (Much of the driveway will drain toward the hole and wash the clay mountain into the hole where the pipe is.)

Sound OK? Any ideas how to do this better?

Thanks For Helping,
Paul

 

[PJB12]

What I Did-

Excavated to expose about 30" x 30" of the wall below grade with the pipe in the center.

Cut the pipe outside about 1" from the face of the wall
Removed the rod that was inside the pipe
Cleaned inside the pipe against oils (if any)

Chipped the block all around the pipe, leaving about 3" of chipped up bare block around the pipe.
This is to give the cement in a later step something onto which to grab

Removed any old foundation tar for in about an 6 -8" circle around the pipe
Basement was added an estimated 73 years ago. I assume the tar is from then.

Washed & Scrubbed the clay off the wall.
Let it dry.

Packed the pipe with closed cell foam (Cut from pipe insulation scraps)
This will hold the cement plug from going too far in.

Put plumber's putty in the pipe, against the foam, as a moisture barrier (Overkill?)

Put waxed plastic (old cracker bag) against the putty to prevent the putty's oils from contacting the cement plug.
Again with the overkill?

Plugged the pipe with hydraulic cement, making a mound to cover the pipe and lapping onto the parts of the block that I chipped up.

Let the hydraulic cement cure for a few days until it was evenly light grey.

Washed & let the wall dry again.

Put about 1/8" thick layer of asphalt based roofing cement (trowel grade) over the entire exposed part of the wall.

Pressed into the roofing cement fiberglass mesh vertically over the mound of hydraulic cement.
(All the local hardware stores, big box and roofing places were out of mesh. I used fiberglass drywall tape.)
The strips were butted and extend several inches past the mound & onto the block wall.

Put another thinner layer of roofing cement & pressed in strips of mesh horizontally this time.

Put another layer of cement to cover the mesh tape.

----------------------------
Can you guys think of anything else I should do before back-filling?

This will be under concrete, so hopefully it will be proper and permanent. The biggest challenge is that it is clay soil, so water isn't expected to drain well. A just-for-fun perk test showed no drainage after 1-1/2 days.