# Underpinning question



## rino1494 (Jan 31, 2006)

backhoe1 said:


> I don't quote to people that share my price. Why help them get the job? If my price is lower, only GC's that will actually use me should be able to plug in that number!



Exactly :thumbsup:

Let's say the other contractor is higher than me. If I give bid to the "other" GC and they use my price which is lower. That gives the GC a better chance of getting the job over the GC that I work for. 

I know the other excavating contractor and talk to him once in awhile and I am friends with one of his employees that I talk to a couple times a week. I know how the other GC works. This excavating contractor has done probably 98% of their work over the last 20 yrs and built a big pond at the GC's house. The other 2% they didn't do was done by lowballers.


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## Redneckpete (Feb 22, 2008)

Sorry I haven't been around for a bit.

Regarding underpinning, I would excavate it to a 1 to 1 slope, at which point it becomes the underpin contractors job. Since I usually do that work as well, here are two tricks for turning the pick and shovel job into machine work.

First, flip the bucket on your excavator around. If it's pin on, it's easy, just pull the pins and flip the bucket around so your machine looks like a mining shovel. That makes it easy to dig under the foundation.

Otherwise, a small bobcat with a 2 foot auger works great. You may need to extend the block on the skidsteer plate so the auger sticks straight out in front, but just drill horizontally under the footing. Carbide teeth work great for weak shale.

There are pictures in the link below. Scroll down to the bottom of the page

http://alphaex.ca/2010/02/24/basement-lowering-and-underpinning/

Pete

http://alphaex.ca


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## green (May 9, 2007)

Pete's right, turning the bucket around works great. Especially if you have a pin grabber Q/A and can spin it right from the seat...amazing how many places you can save on shoveling once you're used to turning the bucket. Just don't forget that you're now digging with the rod end of your bucket cylinder directly in the line of fire if you're trying to dig under something like a footing. We've never tried the auger trick, but thanks for the tip:thumbsup:


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## Redneckpete (Feb 22, 2008)

I've attached a couple pictures of the underpin, that aren't on my website. You can see the auger imprint on the one. Soil conditions were very hard shale, you get a closeup of the soil type in the second picture.

Carbide teeth on an auger bit. Everything that didn't come out with the auger was hammered out with electric jackhammer. It was a tough job.

Pete


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## Greg Di (Mar 12, 2005)

Rather than underpinning with concrete, is there a way to do it with helical piles?

We do a lot of underpinning jobs with our Techno Metal Posts because it's a lot faster, cleaner and surefire than screwing around with concrete.


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## dayexco (Mar 4, 2006)

greg, your photo shows very good workmanship...but as old as i am, i'm looking at getting my building back up to grade, and keeping it there with either a chunk of concrete...or some steel pipe...and some angle iron. i'm going w/the concrete.


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## rustyjames (Aug 28, 2008)

dayexco said:


> greg, your photo shows very good workmanship...but as old as i am, i'm looking at getting my building back up to grade, and keeping it there with either a chunk of concrete...or some steel pipe...and some angle iron. i'm going w/the concrete.


I agree. And I think that all that steel should have at least been hot dipped galvanized.


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## Greg Di (Mar 12, 2005)

rustyjames said:


> I agree. And I think that all that steel should have at least been hot dipped galvanized.


What you are not seeing in that picture is the wired-in cathodic protection we install on Techno Metal Post underpinning jobs. In this picture, you can see them under the building.

That building was completely underpinned in 1-1/2 days.

And no, they actually DO NOT need to be galvanized buried that deep in the ground.

Most underpinning piles have never been galvanized in industrial construction. The galvanization is more of a marketing gimmick to give doubters piece of mind without having to go into eight million reasons why galvanization is not really needed in most applications.


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## skillman (Sep 23, 2011)

Greg Di said:


> What you are not seeing in that picture is the wired-in cathodic protection we install on Techno Metal Post underpinning jobs. In this picture, you can see them under the building.
> 
> That building was completely underpinned in 1-1/2 days.
> 
> ...


Could you do that without excavation of soil .


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## Redneckpete (Feb 22, 2008)

How did you excavate under that footing? Is that a hydro vac hose I see?

Most important to most customers, how does the pricing compare to conventional underpin. Looks like you still need to pour concrete under there if you want to use the space you created. I'm figuring you did this because you were adding to the building and wanted a full basement in the addition.

Pete

http://alphaex.ca


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