View Full Version : How much to build a 20x20 foundation for a garage?


Chevy 350
11-04-2010, 08:15:16 PM
I have a 20x20 shed next to my house from the turn of the century. There are still ceramic knobs inside but not wired up anymore. Its rotten and ready to be torn down.
I saw an ad for a 20x20 steel garage for $3535 in the southern illinois trader. Called and the guy said with 5% discount right now through the factory and sales tax it would be like $3601 installed. This comes with an 8x8 garage door, walk in door, and a window
Framing is 2 1/2 x 2 1/2 14ga steel square tubing I think he said and it installs in less than a day
Thats all fine and dandy but if Iget one I want a concrete floor. Right now its dirt. Im trying to get some idea what it would cost for me to have a 20x20 foundation built for this garage

I was told to have rock packed down and leveled with one foot footings around the whole outside and to go atleast a foot down with the footing.I want 4 inch thick floor. I have no idea how much this will cost but I was told its very expensive

vfw_1168
11-04-2010, 08:19:53 PM
yes it is costly .... call around and get eastments ... if you dont know how to do it your self ... the footer is easy part it is floating the floor and figuring out how many yards you need

Chevy 350
11-04-2010, 08:30:48 PM
Guys at work keep telling me to get a portable building but they just seem kinda junky

vfw_1168
11-04-2010, 08:34:03 PM
yea i know what you mean on that.... i would rather have a pole barn type any day.... my best guess is you will have about 10 to15k in the whole thing.... that is on the high end

Chevy 350
11-04-2010, 08:36:45 PM
jesus

Gary S
11-04-2010, 08:36:51 PM
A wild guess would be that you need around 8 yards of concrete. Depending on what price you can get on the concrete, the cost can go either way. Let's assume $100 a yard so now you have $800. If you do the pour yourself, you can frame it and pour it for under $1000. If you hire someone to do it, expect to pay twice that if your site is already level. To pour a foundation for a building, you need to at a minimum dig around the perimeter for a thickened edge. Any extra excavating or leveling or fill probably would be added.

I poured my 24x48 slab for my garage for under $3000, and put a stick built building on top of it. The final cost for the building and foundation for my 1152 sq ft garage ran around $12k. Then I put more money into insulating, wiring, and finishing the interior. But, I did all the work myself.

At Home Camaro
11-04-2010, 08:52:23 PM
I would think code for you footings would be deeper than 1 foot. In Maryland they are 30" if I remember right. Need to be below the 100 yr frost line.

The above comment would be important if you are getting a permit.

Chevy 350
11-04-2010, 08:58:20 PM
I figured if I [ut the garage right where the old one is they wont even know I tore the old one down and put a new one up
Is 12" good enough to actually work or do I actually need a really deep footing?

mjoc
11-04-2010, 09:05:32 PM
In Los Angelos california. you need to go at least 18". Also don't forget the cost of rebar. You will probably want a sink so you need sewer and water supply. A nice drain in the middle of the floor is nice too. easy clean up.


Mike

Gary S
11-04-2010, 09:08:10 PM
I figured if I [ut the garage right where the old one is they wont even know I tore the old one down and put a new one up
Is 12" good enough to actually work or do I actually need a really deep footing?

Check your local codes. That will tell you how deep you need to go. Around here, a building that has water in it needs 4 foot footings. A building with no water meets code with 12" footings.
And, we get to -45 degrees here in winter, so all this talk of frost line isn't as important as people think.
Check your local codes.

Rich Schmidt
11-04-2010, 09:15:42 PM
You need more then 20 foot in at least 1 direction. A 2nd gen Camaro is close to 17 feet long. You will have almost no room to work in front and behind the car. My attached garage is 21x13 and is 1 car. I would like it more if I had about 23 feet deep. My enclosed race car trailer is 22 foot and the difference is noticeable.

Chevy 350
11-04-2010, 09:22:10 PM
Ive already got like a 25x40 shed, fifth wheel carport, and 2 other carports added on to another shed

BondoSpecial
11-04-2010, 09:25:58 PM
I have two garages, a 22x34 and a 24x24. I would not go any smaller than a 24x24 if you are going to the trouble of building it.

ChevyReb
11-04-2010, 09:26:01 PM
If its a pole building I don't think you will need a footer because the walls won't be bearing any weight/load. If thats the case I would pour the floor 6" deep with fiberglass mix and some re-bar and fence laid down to help protect it from cracking. A lot of people here now scribe lines every so many feet so if a crack does happen it will stop at the lines. If it's a metal building it won't need as big of a footer as a stick built with wood/shingle roof because it's much lighter. Guys doing the building should know all this. Ask for references from recent as well as couple/few year old customers to make sure they have a good rep and satisfied customers!

gordonquixote
11-04-2010, 09:31:54 PM
8 yards of concrete X $85
1 roll welded wire mesh @ $85
12 sticks rebar x $8 each
1 roll tie wire X $10
Concrete bricks to support rebar @ $25
vibratory tamp rental @ $65
1 load crushed rock @ $325
Backhoe rental @ $350
form boards @ $80
Labor @ $1800-2000

Insert local unit pricing as necessary

Chevrolaine
11-04-2010, 09:52:38 PM
8 yards of concrete X $85
1 roll welded wire mesh @ $85
12 sticks rebar x $8 each
1 roll tie wire X $10
Concrete bricks to support rebar @ $25
vibratory tamp rental @ $65
1 load crushed rock @ $325
Backhoe rental @ $350
form boards @ $80
Labor @ $1800-2000

Insert local unit pricing as necessary

This sounds reasonable. Skip the labor and do it yourself though.;)

AFWIW, we put a 22 x 22 wood frame garage on a simple 4" slab with no footings. 30 years later it's still standing and the concrete hasn't moved or buckled from freezing one bit.

masparks
11-05-2010, 12:47:15 AM
I had this put up last fall for a little or $2400. 24x26 x 8' tall and one side. for about the same as you posted I could have had to 8x8 doors a window and walk in door.Now I wish I had. It's portable so your taxes don't go up. In ks. I think if it has a concrete floor it's taxable. Same as a concrete patio it becomes livable space. Maybe wrong about that maybe sortof??
http://i261.photobucket.com/albums/ii41/masparks2001/joshuasparksPICS091.jpg
http://i261.photobucket.com/albums/ii41/masparks2001/joshuasparksPICS090.jpg
Closest I've ever been to having a garage.Better then noughing??

FreedomPenguin
11-05-2010, 03:14:58 AM
whats with the sign on the tractor lol.? just noticed it (:

masparks
11-05-2010, 03:30:01 AM
whats with the sign on the tractor lol.? just noticed it (:

LOL! That's not on the mower it's hanging from the lamp pole. See Ya! or bye,on the other side it says "The Twilightzone".That's what we call our home."YOU READY TO HEAD TO THE TWILGHT ZONE"

My dad made it back in 1970 it will last for ever. :bowtie:

clay's70
11-05-2010, 06:53:16 AM
8 yards of concrete X $85
1 roll welded wire mesh @ $85
12 sticks rebar x $8 each
1 roll tie wire X $10
Concrete bricks to support rebar @ $25
vibratory tamp rental @ $65
1 load crushed rock @ $325
Backhoe rental @ $350
form boards @ $80
Labor @ $1800-2000

Insert local unit pricing as necessary

HAVING YOUR OWN GARAGE $PRICELESS