concrete block and footer questions

[joelowrider]

I am trying to plan on building a garage. I am trying to understand the footer and block part.

I got told by the inspector that I need to dig down 2 foot for a footer, I am not sure how much needs to be poured concrete vs block.

In my head I think about 2 blocks being 16in tall. they say bring the block up 6in above ground so I would have 14 inchs of concrete is this enough or am I even thinking about this right?

 

[readhead]

Without knowing what the code is in your area I would guess a 24” x 8” footing with three courses of block to get you out of the ground.
You should check and see if the building department has a typical foundation detail that you can use.

 

[joelowrider]

Without knowing what the code is in your area I would guess a 24” x 8” footing with three courses of block to get you out of the ground.
You should check and see if the building department has a typical foundation detail that you can use.

They said that they will not inspect for this garage but that I should have the footer at at least 24in

So with you saying 3 courses of block would get you out of the ground with no one checking what are you saying you would do dig down 24in and just pour concrete 6 inches and have the 3 block so it is 6in off the ground?

 

[readhead]

6” isn’t enough footing. You should research typical CMU construction. Are you placing the slab on the wall or as a floating slab inside the walls? Of course all the elevations need to be worked out so you know where you’re heading.

 

[joelowrider]

6” isn’t enough footing. You should research typical CMU construction. Are you placing the slab on the wall or as a floating slab inside the walls? Of course all the elevations need to be worked out so you know where you’re heading.

it will be floating inside of the walls,

thanks on the cmu I didn't even know what to look up I will get to reading

 

[tcianci]

Typically, when you’re told that your footer needs to be 24”, it means that the bottom of the footer needs to be at least 24 inches below grade. That number varies based on your climate. The idea is to foot the building on soil that is deep enough below grade so that it’s not affected by frost in the winter. Frozen soil “heaves” and will cause the building to do so as well.

If you’re gonna build your foundation from CMU, you may find it easiest to pour a footer, the base of which is 24 inches below grade with a level, finished top to start your first course of block on. Ask around your locality to see what is typically considered to be an effective footing.


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[matt_i]

I would go 18" wide x 8" thick, 3000 psi concrete. 3 rebars in it. You just want a massive concrete flat to build the walls on that isn't going to crack& spread apart. Level with a rotating laser level. If you make the top of the footer level then the rest of the job gets easier.

It would be worthwhile to drive a master grade pin (spare piece of rebar) somewhere that's away from the excavation that you don't touch and that becomes the reference for your excavation trench as well as when you start working towards the finished floor. That way you can setup and teardown the laser level setup at will and reference it back easily from the master grade pin on the next setup.

 

[tncatadjuster]

You can find most construction represented on youtube. This is a general idea of what you are doing. If you select the image that looks like a gear and select 2.0 speed it helps.

 

[Kevin54]

I am trying to plan on building a garage. I am trying to understand the footer and block part.

I got told by the inspector that I need to dig down 2 foot for a footer, I am not sure how much needs to be poured concrete vs block.

In my head I think about 2 blocks being 16in tall. they say bring the block up 6in above ground so I would have 14 inchs of concrete is this enough or am I even thinking about this right?

Footers need to be 12" wide and 8" thick minimum (in Ohio in my location) The wider the trench allows for any error in digging and allows the block to be laid straight. Each block is 8" wide, 8" thick, and 16" long. You will want to go a 24" deep for your trench then set your pin height to 16" from the top. Your pins are nothing more than 1/2" x 1'-2' long rebar. If the person digging it uses a footer bucket it will most likely be around 18"-24" wide, so your poured footer will also be that wide. That lets the block layer stand in the trench. There is no gravel in the bottom , and no need for form boards. The concrete will go right against the dirt. DO NOT backfill the trench any if you go too deep. The footer has to be on undisturbed soil.

I reread this and had to edit. You will actually have three courses of block. Your last block will be out of the ground.