Broken Sewer Cleanout Access Pipe

[tspence]

Our sewer access pipe and cover sit at the end of the driveway. The access cover is surrounded by concrete. Over the past year, the concrete around the cover has started to sag - see photos. I had the county utility take a look - they scoped it. It is a 3-4" PVC pipe that runs approx. 10' down to the sewer main. About 5' down the pipe has become disconnected, the rep thought maybe due to ground shift.

I imagine ground water seeping into the pipe is causing the ground / concrete to sag. Is there any way to repair this without hiring a backhoe to dig a 5' hole? There are no sewer issues - just sagging ground. If it is an expensive fix, is it even worth fixing? Could I remove the concrete, use fill gravel / dirt and reapply new concrete?

The square cutout in the concrete around the cover tells me this may have occurred prior and the previous homeowner repaired it?

I'd appreciate any tips - thanks.

 

[Twowaxhack]

Dig the hole, repair the pipe and then put the concrete back.

 

[pasadena_commut]

Our city has a truck with what looks like an enormous vacuum cleaner hose on the front. It blasts water down and then sucks up the mud. I have seen them dig pretty narrow holes (a couple of feet wide) straight down with it, and it is really fast. I think it is called a "hydro vac". Perhaps some company in your area can drive one out and excavate for you. Not sure if the slurry can go back in the hole after the pipe repair though, you might need to buy enough dirt to fill it. Conventional excavation you still have the dirt, but it will be a much wider hole.

 

[Pipe Dreams]

Our city has a truck with what looks like an enormous vacuum cleaner hose on the front. It blasts water down and then sucks up the mud. I have seen them dig pretty narrow holes (a couple of feet wide) straight down with it, and it is really fast. I think it is called a "hydro vac". Perhaps some company in your area can drive one out and excavate for you. Not sure if the slurry can go back in the hole after the pipe repair though, you might need to buy enough dirt to fill it. Conventional excavation you still have the dirt, but it will be a much wider hole.

They are common for use when conventional excavation will be too dangerous or not efficient, like when there are a bunch or power lines and gas and others in the way. Excellent tool.

 

[tspence]

Dig the hole, repair the pipe and then put the concrete back.

Yep - thanks!

 

[Bird Doo Head]

Are the pipes at the shift still aligned enough to slide a sleeve in?

If you have Schedule 40 PVC or Cast Iron & no elbows, Schedule 30 of the same size will slide in. It'll hold the existing pipes in alignment.

You'll have to get creative in attaching the top of the pipe to the existing to hold it off the bottom. Don't let the sleeve go to the bottom or it'll block non-liquid waste from draining from the lateral.
Three 1/4-20 bolts in tapped holes spaced around the perimeter of the sleeve will let you tighten the screws from inside the sleeve until they press against the existing pipe. Friction will hold the pipe suspended. Lexell or similar thick, waterproof adhesive in the gap provides extra insurance. Quick Sketch Is Attached


Plan B: If you have 4", you can slide in 3" and still be able to snake. Even though the cutter will be smaller than the pipe, centrifugal force will make it scrape the walls of the pipe.


Plan C: Some non-plumbing sleeve, such as polycarbonate or acrylic tubing.


Plan D: ($$) Pipe lining company to install a liner.


To Fix The Sag- There are concrete leveling companies who pump a slurry or a foam or an epoxy to fill voids and raise concrete slabs. It works wonderfully & lasts.

Paul

 

[tspence]

Bird:

Thank you for your thoughtful and indepth response. I had a plumber take a look who told me the break is too large to do a liner (photo attached).

Question on this:

Plan B: If you have 4", you can slide in 3" and still be able to snake. Even though the cutter will be smaller than the pipe, centrifugal force will make it scrape the walls of the pipe.

Do you think this will still work given the amount of offset between the pipes? (approx 4" - see photo.) Also, I assume the concrete sagging is from ground water seeping into the pipe at the break. This would not necessarily solve that right? Would just provide cleanout access?

On this:

To Fix The Sag- There are concrete leveling companies who pump a slurry or a foam or an epoxy to fill voids and raise concrete slabs. It works wonderfully & lasts.

I should have thought of that - had to do in in my garage in my last house - slab jacking.

Thank you!

 

[Twowaxhack]

Yep - thanks!

Yep, if you think that’s the expensive way, wait until you blow money on a cheaper inferior fix and that doesn’t work and then you’ll need to then pay for a proper repair. Don’t fall into that trap.

Eventually that pipe will clog and your house will be backed up with sewage and the drain cleaner may or may not be able to clear it. Even if he does that’s just more money literally down the drain, no pun intended.

Plus the ground will continue to sink until it caves in one day as a vehicle drives over it.

Goodluck

 

[pasadena_commut]

Plus the ground will continue to sink until it caves in one day as a vehicle drives over it.

That brings up a point which is confusing me. There are two vertical pipes which separated, both embedded in dirt. Did the top one move up, or did the bottom one move down? If the bottom one moved down then just reattaching the top one doesn't address whatever problem it is that caused the subsidence, so you would have to expect that it is just going to happen again eventually. Seems to me for the bottom one to move down a substantial section of the line it connects to must also be sinking.

 

[Bird Doo Head]

Plan B: If you have 4", you can slide in 3" and still be able to snake. Even though the cutter will be smaller than the pipe, centrifugal force will make it scrape the walls of the pipe.

Do you think this will still work given the amount of offset between the pipes? (approx 4" - see photo.)

Probably it would not work. I'd not try to snake it with the offset because the cutter may hang on the gap & get stuck or leave the pipe. A four inch offset is big.
---------------------------------------------------------------------------------------------------------------------------------
Money is hard to earn, so perhaps we can help you save some to spend with your family instead.

Since your house is still draining, don't treat this as a panic situation. Don't rush into a repair. Check into options and costs at your pace. Treat is like an experience of learning & exploration, not of stress & anxiety. (Life has enough of the latter already.)

The sewer can still be snaked from indoors. Or-
Perhaps investigate installing a clean-out somewhere else outdoors. I installed one on the driveway wall of my house for outdoor snaking. It ties into a soil stack inside. It is an easy shot to the city main. No digging required.
If you do this, you might be able to get away with filling the existing sleeve like that of an abandoned well. A plug goes near the bottom and the pipe is filled with grout.

A Possible Repair To Try-
As the mathematician Archimedes said, "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.".
If the ground is at all cooperative, you could try to use a piece steel post, tube or angle to lever the bottom of the top pipe in line with the lower pipe. A 2 x 4 on edge may work, too. Once I borrowed a stop sign post for a lever.
The lever should be long & you may have to stand on something to reach the top end. (Pickup truck bed?) Have a helper watch to make sure the lever is not below the separation. Pull to align, jerking, but not slamming, if necessary. Sometimes you will be surprised at how easily the pipes align. Been There. Done That. (More Than Once.)

Then you can install a 3" sleeve.
Use a rigid sleeve such as pvc pipe since you're not back-filling around the outside of the pipe. (Some concrete levelers can do the back-filling if you wish.)


Cause:
Perhaps the pavement sinking has nothing to do with the offset. It may be a symptom, not the cause. It may be unrelated.
Perhaps a tree root pushed the pipes apart, or ground frost did it if your frost line is low enough (more than 1/2 the way from top of pipe to shift: 30" to the shift.) A washout from something else? Neighbor draining a swimming pool to the earth? A clay slide? An animal digging? Simply a bad pipe connector that rusted away.
I'm not ruling it out, but there are a zillion possible causes other than the bottom pipe sinking. (You mention no vertical separation, so the bottom pipe does not seem to have sunk.)


I like concrete jacking & leveling. It is strong.
We've had it done in parking lots, loading docks, dock plate cut-outs, factory floors, machine-slab leveling; even a pair of 12 meter tall stamping presses.

It was also used to re-level the slab under the playing field of an NFL stadium where I worked. (Built on a swamp) I have seen 'construction cheats' where piers and columns were "mud jacked" to level.
A few friends & family used it at their homes. No complaints.

I suggest taking your time and exploring options. But most of all, Enjoy This Day!
Paul

 

[Pipe Dreams]

Our sewer access pipe and cover sit at the end of the driveway. The access cover is surrounded by concrete. Over the past year, the concrete around the cover has started to sag - see photos. I had the county utility take a look - they scoped it. It is a 3-4" PVC pipe that runs approx. 10' down to the sewer main. About 5' down the pipe has become disconnected, the rep thought maybe due to ground shift.

I imagine ground water seeping into the pipe is causing the ground / concrete to sag. Is there any way to repair this without hiring a backhoe to dig a 5' hole? There are no sewer issues - just sagging ground. If it is an expensive fix, is it even worth fixing? Could I remove the concrete, use fill gravel / dirt and reapply new concrete?

The square cutout in the concrete around the cover tells me this may have occurred prior and the previous homeowner repaired it?

I'd appreciate any tips - thanks.

if the sewer is running fine, and the lateral pipe is not broken or disconnected, I would leave it alone. Not sure on your ability level or skill, especially with excavation, but that repair would be an expensive one if I did it. 10k probably.

 

[Twowaxhack]

Separated (broke down) sewage piping never corrects itself. It allows surface water to infiltrate the sewer system and it carrys the soil with it. Eventually that area will cave in and you’ll have a hole at the surface.

You can kick the can down the road but eventually it will require a repair.

 

[pasadena_commut]

Perhaps investigate installing a clean-out somewhere else outdoors. I installed one on the driveway wall of my house for outdoor snaking. It ties into a soil stack inside. It is an easy shot to the city main. No digging required.
If you do this, you might be able to get away with filling the existing sleeve like that of an abandoned well. A plug goes near the bottom and the pipe is filled with grout.

Putting in a clean out near the house would be good if it is possible. We did that at one point and it was only 3 feet down where it came out. Easy to dig down to with just a shovel. Not saying the OP's would be that shallow, but if there is a crawl space under the house it should be easy to find out.

When they plug abandoned wells they don't care if the lower end drops grout down further, either immediately or at some future time. Just as long as there is a big solid plug above that . That isn't the case here. So the problem I see is the remaining vertical piece, the lower one. I would be really afraid to try to fill that one with grout for the reasons just mentioned. If the lower seal fails immediately or in future it is going to be $$$ to fix the mess. Capping it would be an alternative, but it won't be easy since a cap for a 4" pipe won't fit through a 4" pipe. They would still need to dig down 5' to deal with it.

 

[MicEd69]

This is NOT a DIY job. The soil has shifted, separated the vertical pipe, and moved the top section. It is now surounded by soil and you will NOT be able to align the two existing sections of pipe without excavating that soil that moved the pipe.

This is not super urgent, but as Twowaxhack said, this separation "allows surface water to infiltrate the sewer system and it carries the soil with it. Eventually that area will cave in, and you’ll have a hole at the surface." So I would suggest getting this repaired in a matter of weeks, not months.

 

[tspence]

Thank you all. Pasadena - you asked how the pipe separated - did the top move up or did the bottom drop? I'm not sure but the plumber thought that at one point the pipe may have protruded up a bit and got run over by a car. He said the pipe looks like it was sheared off. Whatever happened - there is a broken section of the pipe at the top that got broken somehow and the attached photo shows this and evidently how somebody tried to fix it. Does this shed any more light on this for anyone?

Bird - you suggest installing a cleanout somewhere else. Can you provide a bit more detail on how this is done? Assume in the yard which would be fine. Having it in the driveway made no sense to start with.

You have all been very helpful - greatly appreciate.

 

[pasadena_commut]

I don't think that top part is related to the issue at the bottom. The top 5' pipe is firmly embedded in dirt (we assume), so tearing a section off the top isn't going to cause it to move laterally at the bottom. It would probably be very hard to even force it to slide up and down.

It is possible there is already a clean out near the house, but it has become buried over the years. Or it might be hidden by a bush or tree.

As for adding a clean out near the house, assuming it is all plastic at that point, it would just be dig down to the pipe, cut out a section of the right size, glue in the clean out (probably with a slip adapter of some sort on one end), fill in the hole. Ours was more complicated because there was a junction between a big iron pipe running out of the house to clay pipe running in the yard, so they needed an adapter on each end to put in the ABS clean out. A local rooter franchise did the work. As I recall, when the hole floor was even with the bottom of the pipe a person standing in that hole was about waist deep. This is in the sunny part of California though, so it might be much deeper if you are in a place where the soil freezes several feet deep in winter.

 

[Bird Doo Head]

"Bird - you suggest installing a cleanout somewhere else. Can you provide a bit more detail on how this is done?"

At my current house, the soil stack is about 18 inches from the exterior basement wall. That gave me enough space to install a Sanitary Tee on the vertical soil stack. From that, I ran a short pipe to the outside face of the block wall. On that short pipe, I put a flush plug clean-out fitting. It pitches toward the stack for drainage of condensation.
I covered the flush plug with a metal clean-out plate and painted it to kinda-sorta match the color of the block wall.

Hint: To be able to slide the tee in, if there is no wiggle room, you may have to cut the soil stack lower also so that you can remove the section and re-install with a slip coupling or a Fernco type connector. (Assuming plastic. If cast iron, a Mission or No Hub clamp will work well.)

Hint: To cut the hole, if you don't have the proper size of core bit, you can drill with a 1/4" masonry bit all the way around a circle & knock it out. Use a long bit to drill the outside wall of the block at the same time so they align.Try to land between the webs of the block.
I also filled the cavity in the block with mortar because I had to take a web out. I wanted, but probably did not need, the strength of the web that was removed.

Hint: Around the rim of the plate on the inside face, put duct seal to keep the bugs out. Any ambient moisture that collects will be absorbed by the wall and evaporate, just as the water from rain does.

Hint: If you put it in the yard, you can bury it so a mower blade won't hit it. Make a note that you will find showing where it is. (Example: 5' 3" west of house corner, 2' 4" north) And lay a piece of metal on the plug before burying so a locator can find it if you lose the note. A 4" electrical junction box cover works well.


"When they plug abandoned wells they don't care if the lower end drops grout down further..."
The person who installed a new 4" well at project that I was on showed me a plug that expands and holds the grout from dropping into the well, thus leaving the casing open for animals to fall into. Another company, on a different job, built up spray foam to make a plug low in the pipe before grouting.

It looked like a test plug, but it had a standard nut instead of the usual wing nut. He tightened the nut with a curb stop key, but a long socket extension would work. He also said sometimes they simply spray expanding foam & build it up to seal the old casing.

I hope this helps & your repair works out very well.

Paul