Pier foundation for 44 x 24 barn/home

[Noc]

Hello my name is Kimberly and I just got my plans to build a 44x24 barn/home and I'm very excited to get ready to build this spring. I'll be building my home in GA. I am going to do a pier foundation and I have a question about the piers. I will have 15 total piers, 13 of the pier footings will be 24" and 2 pier footings are going to be 36". I was looking at the prices of the round form tubes and they are very very expensive. the 36" x 12' round tube are around$410.00 and the 24" x 12' and costs $268.00. So after adding the costs of the tubes, I am considering just pouring the concrete into the holes and not bothering to spend the extra money on the tubes because the tubes cost more then the actual concrete itself.

I'm going to be using 6x6 pressure treated studs sitting on bracket's that I will insert in the concrete when I pour it so none of my studs are in the ground on in contact with the concrete. My property is level and i won't need to have the piers sticking up that high out of the ground, so can I use 2x6's to form the top of my pier and insert the metal bracket and get same results as if using the form tubes?

We have used this method for building decks up in PA where the winters can be brutal and never had any problems with pouring holes without the tubes and the weather in GA gets down to around mid 40's in the winter. Any input will be greatly appreciated.

Thank You
Kimberly

[MountainDon]

   Kimberly

Question:
What general area of GA? I ask because frost depth varies from only 12" in southern GA, 24" for Atlanta,  Macon 18", Dalton 28" and northern GA up to 30" deep.

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Trying to envision the proposed pier layout. 15 piers total. In three rows of 5 running in the 44 ft direction?  That would make for a very large span between piers; something like 11 feet. That would require huge beams.

More importantly though is that residential codes like the IRC that is in effect in GA, does not list piers as a prescriptive foundation (allowable by the book). By GA law there are 8 mandatory minimum standard codes in effect statewide. (are applicable to all construction whether or not they are locally enforced).
Link to GA Construction Codes Program Description

The reason I asked about the local frost depth is that in much of the south it is easy to construct a foundation that is vastly superior to any pier foundation. Where the frost depth is 12" all that is required is a trench around the perimeter for a 12" deep poured concrete footing. Then a short wall of concrete blocks or poured concrete. Or with a continuous footing it is possible to build a raised floor foundation using CMU's (concrete blocks) as piers that are tied to the footing. This is very different from piers that are individually inserted into the ground. Elsewhere the trench needs to be deeper.

Raised floors link...      Another raised floor link.....

Or a more traditional perimeter crawlspace foundation can be built.

A poured concrete slab may seem expensive at first thought because of the amount of concrete involved. But once it is down it is a ready to build upon floor. With foam insulation under the slab it can also be quite energy conserving and comfortable year round.

I don't want to scare you off the forum, but there are many reasons to not build a home on piers. Piers can be used for decks, but a house is more than a deck.

[rick91351]

Great advise MD as usual!   

By the way  from Rick and Ellen in Idaho. 

Looking forward to see how your build goes......

[bowdog]

I don't want to scare you off the forum, but there are many reasons to not build a home on piers. Piers can be used for decks, but a house is more than a deck.

This is written by a person that built his house (ie, Mountain Don) on piers!  Go figure.  Kimberly, welcome to the forum and don't get scared off by our anti-pier members.  You can indeed build a strong, safe, and long lasting home on piers.  There are some good examples them on this forum.  Some of us are just not as vocal or intolerant of the many safe methods of building a home.

[astidham]

Hi Kimberly,
I built my cabin on post and pier, and What MountainDon is saying about Post and Pier construction is that you still have cost for beams, joist, subfloor, insulation of the subfloor, and the cost of the finished floor inside, hard wood flooring or so on.
the finished product cost of a perimeter footing for a crawlspace block foundation, or a slab, or a post and pier, are very comparable.
as far as forming up 2xs for a smooth above ground finish for your piers, that will be just as good as sonotubes.

[MountainDon]

This is written by a person that built his house (ie, Mountain Don) on piers!  Go figure.

And if the entire thread on my project had been read it would have been noted that along the way I have learned more about structures and foundations. HERE and HERE. 

To summarize:

Since the completion of the cabin I have talked with two engineers and one very experienced builder. If I had spoken with any one of them in the planning stages I would have built differently. As it is I spent time, effort and money making some changes to the piers. Not because there were visible problems happening, but because I thought it best to head off some potential issues. The piers now have lateral bracing that will go a long ways to ensuring their stability. I have also since learned that my location has more seismic potential than I imagined a few years back. Not as bad as CA and some other points. OTOH, one engineer who actually visited the property has said that in his unpublished, unstamped, not officially approved opinion, we are probably safe especially with the retro fitted shear walls. He stated that only because he knows the geology of the area and knows the soil mix is well drained.

Still, I am happy that I took the time, effort and money to retrofit the shear walls.

Life is a journey. We learn along the way if we listen to mentors. It would be remiss of me to not pass along what I have learned. Everyone is free to choose to learn along with me, or not.

No need to sign up as a newbie to make critical comment either.