Shed foundation

[kerwinq]

Going to build a 12 x 16 shed and would like to do footings then pour cement inside of that for the floor. Want to get it above the ground so water does not get in is the reason for the footings. I am thinking 6 inches below grade and 3 inches above would be enough. Yard is fairly flat

Does this sound reasonable?

First time building a wood shed and want it to last

Any advice is appreciated

Thanks, Kerwin

 

[kaymccampbell]

Just pour a mini alaskan slab on the surface, that way it'll automatically be 3" above the surrounding grade. And you'll have more material for deeper footings.

 

[Los_Control]

Just another idea for you, your idea is really good and will produce a nice floor for a lot of labor.

What I will do, Heavy exterior 6" galvanized metal studs. These are used for exterior framing on commercial buildings. Very stout.
Build a floor frame with them, and cover with 3/4" plywood. Very simple process and good and solid as the floor in your house.
I plan to set mine up on 8"x16" blocks and that is a bit cheesy but works well. And building walls in a couple hours. A customer paying by the hour appreciates that.

A guy can bury the blocks to lower the floor height ... Or a guy could pour footings for it to sit on,
Use a 2"x4" and make 16" x 16" boxes sitting on the ground for concrete forms, dig a hole for 8" thick concrete ... mix a couple sacks of concrete and pour them. Probably want 12 pads for that shed.

My only point is, a full blown footing and slab is nice, going to need to hire a crew and get some help with concrete. Going to be some extra cost involved that really is not needed. You can achieve your goal for a lot less time and money.

 

[nadogail]

IMHO, The monolithic slab is the Cadillac of foundations for your project.

 

[Los_Control]

IMHO, The monolithic slab is the Cadillac of foundations for your project.

I wont argue with that. My opinion is for a do it yourselfer building their own first shed.
Pouring the slab is going to require outside help.
The original poster may have no plans of doing any of the work, or hopes to do it all.
I have no clue, they did not say.

First time I saw the metal construction of the floor framing. And have used the material many times in the past ... To me it was a no brainier to stop using wood stringers.
Add the pads to set it on, it will last a lifetime and easy to work with.
And easy to walk a first timer through.

I always love picking up the phone and spend others money, say get er did ...but if I have to do it, things change.

 

[kerwinq]

My intent was to dig what I needed for the footings and foundation but to have the cement work done, I am not into working that hard!! Building the shed is what I was planning on doing myself. Knowing it may take a little time to complete but that is ok, if it turns out ok I want to build another a little bigger as a workshop.

I thought footers were usually higher than the floor but maybe I am thinking of something else. I want to keep water out and thought if they were higher it would reduce the chance of water coming in from rain or sprinklers.

Appreciate the responses

 

[Los_Control]

What others are talking about with a monolithic slab, you prepare the total surface for a 4" slab, but on the edges you dig it deeper and just pour the edges thicker for the walls to sit on.
In the process will want to add rebar and the slab will need wire, during the pour will want to add J bolts ... There is talented work to setup the forms and make it pass code and also proper concrete finishing.
If you are not comfortable with it, I would not suggest a 12'x16' slab for first go around.

A footing in a house, you pour, then you lay down a sill plate and bolt it down and then you build your walls on top of it. leaving a dirt crawl space ... your floor joist sit on top of the sill plate.
Footing in a attached garage on a house, the footer is poured (foundation) then later a slab is poured inside of it. Including driveway and proper pitch for water drainage.

What you describe in your first post, it sounds like two separate concrete pours and just not needed.
For a shed, the mono way will work but I suggest you hire it out. Removing a bad concrete job is not cheap.
For a way to do it at home for yourself, I say going pier pads is a good way ... While simple blocks have worked on mobile homes for over 100 years, just depends what you want to do.

 

[pima67]

When I built my 8x12 shed in Ogden, UT, I prepared the site (level & packed sand for drainage), and set used railroad ties (3 or 4 - can't remember) as the foundation. Then I built a conventional floor of rim joists & joists with plywood as the flooring on top of the ties. Solid as though built on bed rock.

 

[The Cobbler]

I would do a monolithic pour. thickened edges and 4" of concrete on floor. you should seek advise of authority having jurisdiction for proper specs.
My shed was done with 12x12 thickened edges and 4" floor of I recall correctly

 

[Bolson32]

Just hire a slab man. Footings are massive overkill. Even a slab is, but if you want it, go for it. You'll have plenty of labor in building the shed, you won't save a ton of money DIYing the slab and it could turn out ******.

Sent from my SM-G965U using The Garage Journal mobile app

 

[LS6 Tommy]

IDK about where you're at, but around here if you have a foundation or slab, it becomes a permanent structure, therefore it's taxable space and you need to get permits, etc...

Tommy

 

[CraigStu]

IDK about where you're at, but around here if you have a foundation or slab, it becomes a permanent structure, therefore it's taxable space and you need to get permits, etc...

Tommy

Same in Md when I built an elevated playhouse for our daughter. I was going to use six 6x6s as the stilts and had planned on digging maybe 12 inches. Then a friend told me about permanent vs temporary. So I bought two 2x8s and lag bolted them to the bottoms of the 6x6s so the playhouse sat on the grass. It was maybe 5' wide by 10' deep and it was so solid I was actually surprised.

 

[astroracer]

Yup, check your codes. If you want it permanent you have to pay.
If you go/want permanent you could also do a small pole structure and pour the floor inside the rat walls. This could end up being half the price of a stick built if you aren't heating/cooling it.
Mark

 

[Los_Control]

Always check for needed building permits. getting caught in the middle of construction without needed permits, stuff nightmares are made of.

Here in West Texas I live in a small town, I checked with them about building a shed.
We are allowed up to 200 square feet and no permit needed. Do what you want.
Same time listen to interview on local radio station. Inspectors encourage you to call and ask if you have questions. They would rather stop by and see what you are doing, offer advice on best plan forward. Not try to penalize you for improving your property.

Boise ID, you have some weather there, Not sure what you need for footings or a mono slab.
General rule, footings need to be below frost line, and mono has specs also. You really need advice from someone in your zipcode, or familiar with the requirements.

I drove through Boise a couple years ago in January. That was a white knuckle drive.
Total white out with the snow, could only see a few feet ahead, was a semi in front of me doing 25-30 mph on freeway, I just followed him. If it was safe, I would have pulled off and waited it out. I was in middle lane, I could not see out side windows for safe lane change, we just had tracks to follow and the snow was piling up inbetween lanes ... just keep moving is all we could do.