# Garage footer/slab question



## rico55 (Nov 27, 2005)

I am designing a house that has a an attached garage. It is a two story house, with a single-story garage. What type of footer should the garage have? Should it be the same size and depth as the rest of the house? Do I need to leave a gap in the stem wall where the garage door is?


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## wasdifferent (Dec 18, 2004)

rico55 said:


> ...What type of footer should the garage have? Should it be the same size and depth as the rest of the house?...


Talk to a local geotech, or a structural engineer. We don't know what your local soil conditions are. 




> Do I need to leave a gap in the stem wall where the garage door is?


It's a good idea to have the elevation of the stem wall high enough to keep the framing off of the ground. This usually means that you have to make a cut in the wall for the apron and the overhead door. A cut in the wall is not difficult, nor is it expensive. 

I hope that this helps,


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## shopdust (Apr 9, 2005)

A lot depend on your local codes (interpetation) I.E. In most areas your footers would be 15" X 18*" in the two story area, 12"X12" in the garage area. These are the dimensions of the footer going into undistrubed earth or compacted fill, not including the 4 inch (nominal) slab. A quick call to your local building authority will tell you what's req'd in your area.
I would pour it as one unit - monolith

*Or the depth will be below the frost line, again that is a local determination.


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## PipeGuy (Oct 8, 2004)

rico55 said:


> I am designing a house... What type of footer should the garage have?


Do you have an architect?


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## JustaFramer (Jan 21, 2005)

shopdust said:


> A lot depend on your local codes (interpetation) I.E. In most areas your footers would be 15" X 18*" in the two story area, 12"X12" in the garage area. These are the dimensions of the footer going into undistrubed earth or compacted fill, not including the 4 inch (nominal) slab. A quick call to your local building authority will tell you what's req'd in your area.
> I would pour it as one unit - monolith
> 
> *Or the depth will be below the frost line, again that is a local determination.



Those are some huge footings depth wise. However is all has to do with the soil. Over the years I have seen 6" deep x 12" to 8" deep x 12"-24"


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## shopdust (Apr 9, 2005)

JustaFramer said:


> Those are some huge footings depth wise. However is all has to do with the soil. Over the years I have seen 6" deep x 12" to 8" deep x 12"-24"


Ayyyup!
jumped into many a trench with a square tipped shovle to clean out spill or extend the depth beyond what the inspector thougth was fill. Earthquakes (and the subsequent lawsuits) are big issues in California.


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## JustaFramer (Jan 21, 2005)

shopdust said:


> Ayyyup!
> jumped into many a trench with a square tipped shovle to clean out spill or extend the depth beyond what the inspector thougth was fill. Earthquakes (and the subsequent lawsuits) are big issues in California.



It won't suprise me if WA will go that deep in the future one good quake and we will again radically reengineer.


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## shopdust (Apr 9, 2005)

Some 'experts' think the Pacific NW is overdue. That little shake in Seattle made folks think.

Some jurisdictions in Calif. are now allowing 2d stories on remodel residences with 12' x 12' footers over 5 years old. Concrete seems to get harder?
I'm aware of the 90% at 28 days mix, wonder when it tops?


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## Tom R (Jun 1, 2004)

I think it's 'years and years', - - might wanna get Justaframer's answer.


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## JustaFramer (Jan 21, 2005)

I am still learning with concrete. I work for others on this trade. I have done alot of prep for pours. Set up forms run some rebar. I think I am wrong but it's 65,000-90,000 psi in 28 days. but takes still takes a few years to fully cure.


way over shot that one 3,000 at 28 days. High strength considered at 7,000-14,000 psi


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## JustaFramer (Jan 21, 2005)

http://www.cement.org/basics/concretebasics_faqs.asp


Here is a good fact sheet (I think) on concrete.


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## wasdifferent (Dec 18, 2004)

JustaFramer said:


> Here is a good fact sheet (I think) on concrete.


It is. 

Portland Cement Association
www.cement.org

American Concrete Institute
www.aci-int.org

National Readymixed Concrete Association
www.nrmca.org

Concrete Reinforcing Steel Institute
www.crsi.org

ACI membership is a good investment. _ACI 318 Building Code Requirements for Structural Concrete_ gives you the information that you need to meet the Code.


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