Heavy rains - right after tunnel slab leak repair!! Help!! (West: insurance, inspections)

[naterator]

Hi everyone! We just had a tunnel slab leak repair done last week. Just in time to see to see a little creek of water water rushing into the place where the tunnel was dug out during the heavy rainfall the last couple of days. Haven't had a chance to look closer at it, but there's definitely an opening under the foundation where the tunnel was. Wondering if anyone has had something similar happen and what you did? Thinking a sump pump and more dirt for a start. Thank you!!

[FalconheadWest]

Contact the people who did the repair. They'll be the best answer to your question.

[MckinneyOwnr]

Originally Posted by FalconheadWest

Contact the people who did the repair. They'll be the best answer to your question.

Or not, since they clearly didn't fill in the hole completely after they finished.

Not sure a sump pump will help here, the water will have continued to drain down through the dirt, leaving just mud and empty space beneath the foundation.

I'd still call the guys up who did the repair, but I'd be surprised if they do anything for you. Might need to call a structural engineer instead.

[EDS_]

Originally Posted by MckinneyOwnr

Or not, since they clearly didn't fill in the hole completely after they finished.

Not sure a sump pump will help here, the water will have continued to drain down through the dirt, leaving just mud and empty space beneath the foundation.

I'd still call the guys up who did the repair, but I'd be surprised if they do anything for you. Might need to call a structural engineer instead.

It's SOP to leave those tunnels unfilled most of the time. I know, right. I don't like it either.

[escanlan]

Originally Posted by naterator

Hi everyone! We just had a tunnel slab leak repair done last week. Just in time to see to see a little creek of water water rushing into the place where the tunnel was dug out during the heavy rainfall the last couple of days. Haven't had a chance to look closer at it, but there's definitely an opening under the foundation where the tunnel was. Wondering if anyone has had something similar happen and what you did? Thinking a sump pump and more dirt for a start. Thank you!!

From your description it sounds as if the company performing the work did not properly backfill under the foundation and compact the soils IN STAGES when it was being replaced. Simply throwing the soil back under the foundation does not properly backfill/compact it and this type of situation can happen. Simply adding more soil is not the answer as eventually it too will subside until the soils have been properly replaced and compacted.

You should immediately be calling the repair company to have them out and explain why this occurred and what they plan to correct the issue? You should obtain this in writing as well. For the safety of your foundation, and your wallet/pocketbook I would advise you speak with a licensed Professional Engineer about this situation and any planned action to correct it by the company who performed the work.

Just out of curiosity was there any foundation work associated with this leak/repair?

Good luck and let us know how it progressed.

[EDS_]

Originally Posted by escanlan

From your description it sounds as if the company performing the work did not properly backfill under the foundation and compact the soils IN STAGES when it was being replaced. Simply throwing the soil back under the foundation does not properly backfill/compact it and this type of situation can happen. Simply adding more soil is not the answer as eventually it too will subside until the soils have been properly replaced and compacted.

You should immediately be calling the repair company to have them out and explain why this occurred and what they plan to correct the issue? You should obtain this in writing as well. For the safety of your foundation, and your wallet/pocketbook I would advise you speak with a licensed Professional Engineer about this situation and any planned action to correct it by the company who performed the work.

Just out of curiosity was there any foundation work associated with this leak/repair?

Good luck and let us know how it progressed.

The newer way to handle this is to not backfill at all at least much of the time. Before you say I don't what I'm talking about.

1. My best friend is plumber who does the plumbing end of this kind of work all the time. He's also my go to plumber for commercial interior finish out work - ADA compliance etc.
2. A good friend of his owns a company that digs these tunnels everyday. The workers take 30lb. electric jack-hammers and spade bits slicing through the clay like cheese.
3. I've read engineering reports, supplied by #1's engineer. Boiled down the notion is backfilling via normal compaction methods doesn't work well enough to justify the expense and there is nearly always post compaction shrinkage rendering the work a colossal waste of time. And except in cases where the tunnel will fill with water and stay filled for a good while leaving the pit does not damage to a slab foundation so long as the tunnel is less than a certain width 36" IIRC and these tunnels are usually less that 3ft. wide.
4. Insurance companies are OK with all this.

[ru4real]

were permits issued?
some munis have criteria on tunnel backfill
Foundation Inspections - Plumbing Repairs

[escanlan]

Originally Posted by ru4real

were permits issued?
some munis have criteria on tunnel backfill
Foundation Inspections - Plumbing Repairs

A very good article/post on the proper methods for performing this repair and backfilling afterward. Obviously properly filling in the void costs more money and some that perform this work do properly quote the additional costs. Unfortunately those that don't will quote the lower cost of improperly backfilling or not even backfilling at all which is significantly cheaper and they many times do get the job as a result. In the end the consumer loses with the cheaper bid!

Hopefully the OP will pursue this with those that performed the work to find out what is occurring and why.

[naterator]

Thanks for all the input. The article was also helpful. Originally, I was adamant about no tunneling, because the first plumbers wanted to do a 65"x65"x12' hole (yes over five feet square), so he could stand up while doing the repair. And tear up my yard and patio. The second plumber (who has done 58 of these this year) said that's a terrible idea. His proposed tunnel was 32" x32"x12', but ended up being about 30"x30"x8', just enough for the plumber to wiggle in and fix the section of pipe. He found the leak sooner than the sound test let on. The backfilling method was as proscribed in the article, by pumping and using the original dirt, tamped down as much as possible. Turns out I've got a plugged section of gutter (we moved in not too long ago) that was overflowing right where the tunnel was. Of course. Which is why I think it looked like a small creek, watching it front the window. Finally got a better look at it today and it doesn't look like there is a hole there, just a really low spot. Still going to get a PE out here to look at it. And definitely get that dirt sloping back away from the house. I'll let y'all know what they find. Thanks again for the replies.

[escanlan]

It sounds as if you had one of the Plumbers who knows how to properly finish the job, good for you! At this point an Engineer would not be able to say much more if all they see is a depression. If all you have is some low soils then the answer would be to place additional soil there to fill and slope it away from the foundation.