16" thick I've never seen any footing over 8" thick.
#1 you need to go back and add you location to your profile!!
How did you set the grade stakes?
No idea on if rebar is needed, twice as much concrete that's needed, sure you really want to be DIYing this?
If this is messed up the rest of the building will follow.

 

Id ask the fellows you ordering cement from.

 

I'm going to move this to concrete for you----

 

That is a rather thick footing---I don't know what your soil is like or your codes--so that might be the normal size for your locale----

Rebar is frequently place low in the footing in areas with soft or sandy soil---I put rebar into my houses footings --they weren't required ,but the added cost seemed like good insurance--

I am not a mason--I am allergic to shovels---so if a concrete guy chimes in---ignore my post.

 

Is this a one story garage? There are houses as far as the eye can see out here in Detroit with no footers at all.

 

No footer
Not so sure about that one.

 

Yes, very sure, it is very common. At least with houses over 80 years old. I live in a vast wasteland of houses, they are falling down right on my street.

 

Let think about this, there 80 years old and there falling down.
HMM
How does that have anything to to do with the O/P's question?
Still have no location.
No size of the building.
Single story or two.
So everyone's still having to just guess.

 

The foundations are strong, the houses are falling down because of the roofing fail. Down south by you many many houses are just built on rocks. My point is you could get by without a footer. Although not ideal it was done successfully in this country for 100 years or more

 

Most of the footings I see have rebar in them. Not much, maybe one or two lines of it, and mostly to tie in the steel for the stem walls. So yeah, put some in, but there's no need to over do it.

 

New Jersey.

Problem is that my footer bed is REALLY unlevel - I can either pay $3600 to have someone else do them, spend a day with a shovel fixing them, or pay an extra grand in concrete and just make them super-deep... well, actually super-deep in some places and normally-deep in others.

 

Can't you just put some dirt back in the areas that are super deep? That seems like the cheapest way.

 

Your plans should specify how much rebar to use. The guy I hired to build the foundation for my log home was amazed at how much was called for. I've never seen footers without at least some rebar. Footers are too important to leave to chance.

 

Your plans should specify how much rebar to use

I don't have any plans. This project started as a patio - then I was like, "wow, this skidloader moves a lot of dirt, bet I could move this hill and build a garage"

 

It is a strip footing there is often no requirement for rebar, but 2 or 3 longitudinal one are good practice. - A code is just the minimum standard, but you are allowed to do better.

The length wise rebar make the footing and stem wall work together into a very stiff reinforced deep beam that can span over areas with poor soil and not have settlement cracking, since very rarely are soil borings done for small jobs. A common rule of thumb is the the width of footing should be the width of the foundation wall plus 2 times the MINIMUM required footing thickness. This allows you to avoid cross-rebars if you overdig the footing depth.

If you building a garage, may be better to build the stem wall (block or concrete) from the footing upward about 8" above the planned slab elevation. This allows you to have a floating slab that can be poured later and will get you siding above grade and easy to wash out and provide drainage to wherever you want (front door or central rock well) if you track in salt and debris.

Dick

 

If you building a garage, may be better to build the stem wall (block or concrete) from the footing upward about 8" above the planned slab elevation. This allows you to have a floating slab that can be poured later and will get you siding above grade and easy to wash out and provide drainage to wherever you want (front door or central rock well) if you track in salt and debris.

my FIL built a garage that way. i wouldn't doubt he did it wrong. but after many years, things started settling in different directs. you wouldn't believe the mess that garage is. forget about having the doors seal.

imo, a mono slab, for a regular garage is the way to go.

 

I don't know why no one is answering your question, so here goes.

No you do not have to put rebar in the footer, just like there is no law that is requiring you to put gas in your car. Of course if you want to drive the vehicle, then the laws of physics will eventually compel you to add gas.

Likewise, the cost of rebar is so minimal to the overall construction expense, that it simply becomes a very cheap form of insurance.

Two pieces of .5" bar evenly spaced near the bottom of the footer, sitting on a few evenly space bricks, is easy to do. I have also placed the concrete first and then set the rebar on top and tamped it down with a rake.

The only concern with a variable depth footer is that the minimum thickness is sufficient to carry the load. I helped a guy poor a footer for his house. He ordered too much concrete and by the time we got around to the garage area we had about 4 extra yards that he could send back to the plant or use it in some way. He formed the ends of the trench around the garage and filled the garage footer up over 2 feet thick. His response was "there are worse places to waste concrete than in your footer"

The extra thickness is only hard on your wallet, nothing more.

From experience, a sloppy footer ends up making a sloppy foundation, which ends up making a sloppy building. Can't really explain why, but that is how it goes almost every time.

 

Excellent, straight forward advise, from someone who does it for a living.......:thumbsup:

I always say: "Unless you can figure out a way to put the rebar in later, after the concrete failed, I'll just put it in right away"......

As for the concerns over the OP's footing depths, I also think they're unwarranted. I've yet to run into a building inspector who was concerned that our footings were too thick. Or a soil engineeer. Or a structural engineer. Or a state building inspector. Or a civil engineer.......

Variable depth footings occur all the time, wether it's intentional or not. It's not uncommon for the excavator to run into bad soil on a portion of the excavation, and then step the footing down through this area. If it's CMU walls, you can do an 8" jump in the footing, or just pour it thicker depending on how long the section is.........

 

Fix'n -

That was be acceptable in you climate or even somewhat satisfactory for a detached garage.

If the garage is attached, the foundation for the garage should be the same foundation as the house itself, because the become one structure.

There is no substitute for going down if you have frost problems in your area. A strip footing is faster and idiot-proof and provides more flexibility regarding elevations and drainage, plus it gets the rot-prone wood far enough above grade an allows a higher garage door (if desired) because the wood is on the curb above the slab that is poured much later.

Dick