Pouring footers in muck

[LevelZeroHero]

Hi all,

I have a mason who is attempting to install a 20x15' 6' tall block wall foundation for me. He's made the dig for the foundation and is trying to get footers in the ground. However, being in soggy Upstate NY in the spring, the weather has been atrocious. He has had to call his excavator back to the site to cut back the banks of the excavation because the hole kept collapsing. Ultimately, we had to dig a trench at one end that I'm running a pump in every two hours to drain the hole.

Needless to say, the pit is a mucky mess. What once was a nice excavation to virgin soil is now a mucky mess with holes here and there, running water, and 2-3" of pure muck in places before we get down to a solid footing. In these conditions, he wants to pour the footers tomorrow, right as we're supposed to get another 0.65" of rain. I'm concerned that the resulting footers won't be sitting on solid ground and won't end up very strong.

He is reluctant to push the pour because he doesn't know when he can get another concrete truck back. I honestly think we made a mistake by digging the hole (on Monday) and not attempting to pour until Friday. It's been a wet spring and water continues to flow into the hole from various points in the 6' excavation near the bottom of the banks.

Do you think I should go ahead with the pour or try and let the hole dry out more? There's really no telling when that might be, but I'm afraid of ending up with weak footers.

Thanks for your thoughts.

 

[kaymccampbell]

Usually, we dump a truckload of compactable fill, or just 2's n 3's into a muddy hole. Then smash it in with an excavator bucket. We dump riprap if the muck is deep.

 

[LevelZeroHero]

Thanks, friend. I see you're also in Upstate NY so you're dealing with the same slop we are this spring. I think your idea is a good one. I don't think my contractor is really interested in doing that, unfortunately, so I may have to do it myself. I had considered something very similar when I saw this other post online. It's good to hear it's done in practice!

 

[nadogail]

Concrete can be poured underwater if you use a Tremie. Google " Tremie "

 

[gmcgeo]

Concrete can be poured underwater if you use a Tremie. Google " Tremie "

my understanding of a tremie its a watertight pipe that goes into the water not an application to actually dump into the water? or am i wrong?

very interested how that would work on a footer

 

[Renegade1LI]

You need to stabilize the subgrade, if you pour on unstable soil you will get settlement, as Kay said stone is your best bet, just don't let him place concrete on mud. Keep in mind of the soil is saturated and expanded when it dries out it will settle, rule of thumb don't pour on expanded soil, remove and replace with stone or add extra concrete.

 

[turbowoodworker]

No one ever died from a "concrete emergency". If you are uncomfortable, postpone it. It's your project, your money.

 

[mshedb]

We had some shrink-swell type soil in the back corner of our garage’s site. Excavator was on site and kept digging the footer deeper until the sides held up. County inspector watched the whole thing. I think the footer wound up 9’ thick in that corner!

 

[pcmeiners]

"You need to stabilize the subgrade, if you pour on unstable soil you will get settlement, as Kay said stone is your best bet, just don't let him place concrete on mud."

As an example of the results of pouring on mud.... Next door a backhoe operator dug most of the footing for a new home, newbie took over and over-dug a corner of the footing area, resulting in mud slurry. They dumped gravel in the area to make up for the newbies learning experience... end result , the foundation cracked in 2 places, the resulting piece sank and is still sinking after 4 years.

 

[Pntyrmvr]

Footing has to go onto undisturbed soil. No amount of tamping is going to result in a predictable bearing capacity under that footing.

It might take a while to show up, but frost will exacerbate the problem and something will sink.

It’s going to be dry next week. Book the backhoe the day before the concrete mixer and do one last scrape.


“Talk is cheap. Whiskey costs money.”

 

[nadogail]

my understanding of a tremie its a watertight pipe that goes into the water not an application to actually dump into the water? or am i wrong?

very interested how that would work on a footer

The outlet of the Tremie would be in the watery muck at the bottom of the excavation.

 

[LX-Markham]

We pour a “mud-slab” immediately after excavating. It’s a 2” thick low strength concrete that seals the excavation and prevents the undisturbed soil from getting disturbed while you prepare to do the proper footings. Especially important when dealing with swelling clays.

 

[Dagny]

Don't know what kind of soil you have but in hard pan the water just stays on top and I remember pouring right into the water and the concrete just pushes the water out of the forms.

 

[ConCretin]

Ok, stop with the nonsensical tremie discussion. It isn't applicable as the OP rightly noted. The only option is to scrape out the muck and replace it with crushed stone. Period. Dig a sump at a low spot and put in a 5 gal pail with some holes drilled in it to pump out any ground or surface water. The stone will provide a work surface that prevents concrete operations from churning up the base.

It would have been better to da all this before you started but it's never too late. Do not place your foundation on slop.

 

[four.cycle]

This thread reminded me that when they built what is now called "The Columbia Tower" in downtown Seattle (aka "The Darth Vader Building") they went down 90 feet to pour footings for the building.

 

[Viper98912]

Good advice here; I'm going to follow up with the comment "It's your project, your money." And at the end of the day, you're the one who's going to live with it, not the contractor.

 

[97tj-neil]

I was in college (RIT) back in the 90s. I did an internship at New Venture Gear in East Syracuse. I kept track of one 14 day stretch where is snowed every.day.for.14.days. That misery turned into the muddy spring you speak of. I had 2 job offers at that time; one in East Syracuse and the other 6 hours or so south in the Harrisburg, PA area. I took the job in PA and never looked back.

My advice is to move at least that far south - further is better. You will never regret it.

 

[ConCretin]

Let me elaborate a bit on my previous response for anyone clicking on this thread in preparation for starting a foundation. If you think you may have groundwater or may get a lot of rain while footing construction is in progress, it's smart to get in front of the problem.

Over excavating just a few inches and placing stone will do two things. It provides a stable work surface so construction traffic doesn't churn up the base and it provides a void from which water can be pumped to maintain a dry hole.

We do mostly commercial work but we always make this suggestion. I can't count the times the GC didn't want to spend the money only to spend a lot more in time and money when a failed pre-pour results in everyone starting over.

 

[mike93lx]

Who's money is paying for the work?

That is the guy that makes the decisions

 

[matt_i]

If you want to see a guy (aka me) suffering thru the same issue, then here's a snippet.

https://www.garagejournal.com/forum/showthread.php?t=319602

Around the middle of page #1.

I waited, it took me almost a whole summer to recover. Finally poured the floor the week before Halloween. I subscribed to "only pour on undisturbed soil" mantra. The rock fill is good but its a compromise as that aggregate doesn't have the same "bearing area" as the flat-ish bottom of the footer. (IOW think of what it would take to smash some rocks into the subgrade... The good news is that for a garage without second floor loads you can get away with this corner-cut.

I got super strong working for a couple hours everyday hand-scooping/throwing the gucky mess out of the trench. The good news is the schmootz that fell back in was basically fines washed down from the walls, my actual trench-bottom was more or less unaffected in vertical dimension. I was initially worried it was going to be like a bottomless pit with no end to the soft soil.

As you say the lesson learned is to find a window in the weather and cancel all other activities including your day-job (take vacation!) and work 18 hour days until that footer is poured on solid ground.

The day you get out of the dirt and begin working on a flat, relatively clean, paved surface is indeed a good one!

 

[nadogail]

I was in college (RIT) back in the 90s. I did an internship at New Venture Gear in East Syracuse. I kept track of one 14 day stretch where is snowed every.day.for.14.days. That misery turned into the muddy spring you speak of. I had 2 job offers at that time; one in East Syracuse and the other 6 hours or so south in the Harrisburg, PA area. I took the job in PA and never looked back.

My advice is to move at least that far south - further is better. You will never regret it.

You will love the San Diego area, the next door neighbor here went to Rensselaer in Troy.

 

[pstnbly]

Ok, stop with the nonsensical tremie discussion. It isn't applicable as the OP rightly noted. The only option is to scrape out the muck and replace it with crushed stone. Period. Dig a sump at a low spot and put in a 5 gal pail with some holes drilled in it to pump out any ground or surface water. The stone will provide a work surface that prevents concrete operations from churning up the base.

It would have been better to da all this before you started but it's never too late. Do not place your foundation on slop.

^ This +1

 

[rustyjames]

You could also use recycled concrete for a base fill, it's a lot cheaper that crushed stone.

 

[Bighead38]

Ok, stop with the nonsensical tremie discussion. It isn't applicable as the OP rightly noted. The only option is to scrape out the muck and replace it with crushed stone. Period. Dig a sump at a low spot and put in a 5 gal pail with some holes drilled in it to pump out any ground or surface water. The stone will provide a work surface that prevents concrete operations from churning up the base.

It would have been better to da all this before you started but it's never too late. Do not place your foundation on slop.

I do this at work at least a few times every month. Muck it out and add stone. The other option is to muck it out and just have thicker footings.

You could also use recycled concrete for a base fill, it's a lot cheaper that crushed stone.

That would fail inspection here. Needs to be clean stone.

 

[rustyjames]

I do this at work at least a few times every month. Muck it out and add stone. The other option is to muck it out and just have thicker footings.



That would fail inspection here. Needs to be clean stone.

Wow, that's a shame. I worked on government projects here that it was used extensively under footings.

 

[manwithtools]

You could also use recycled concrete for a base fill, it's a lot cheaper that crushed stone.

Wow, that's a shame. I worked on government projects here that it was used extensively under footings.

I do this at work at least a few times every month. Muck it out and add stone. The other option is to muck it out and just have thicker footings.



That would fail inspection here. Needs to be clean stone.

Interesting, recycled concrete will compact very nicely leaving a strong uniform base. Hard to believe that it isn't allowed for foundation use in Bighead38's area.

 

[rustyjames]

Once RCA is compacted it's almost like concrete again. It's a great base and is used extensively here, especially on government projects.

 

[Bighead38]

Interesting, recycled concrete will compact very nicely leaving a strong uniform base. Hard to believe that it isn't allowed for foundation use in Bighead38's area.

I honestly don’t know why. Maybe it’s because it has fines in it and doesn’t drain as well? I know a job we were on a few months ago the builder had me put rca in because it was cheaper and the inspector made me dig it out.

 

[rustyjames]

You can get RCA without the fines, it's available in different gradations from some suppliers.

 

[Bighead38]

You can get RCA without the fines, it's available in different gradations from some suppliers.

Maybe that’s the difference people are talking about. Quarry’s are different based on the region. Here RCA has fines, as far as I know it’s not offered here without it.

 

[pmiranda]

I thought you were supposed to have gravel (Or rock, forgive my lack of technical accuracy) under any footing, even if dry?

 

[Pntyrmvr]

Undisturbed soil. No organic material.


“Talk is cheap. Whiskey costs money.”