Pouring my own garage floor.

[scesnick]

I built a new pole garage recently 30x40 and I also got a new concrete mixer for a smaller stone veneer project. I need a floor in my garage still and I was wondering if anyone here has poured their own floor with just a 8 cubic Ft. mixer?

I realize it is a big job but why can't I just pour sections ? I am really in no hurry at all. Any opinion is welcomed. I am just thinking out loud here and will most likely just bite the bullet and pay the $2,500 and have someone pour it for me.

 

[EddieWalker]

Hire it out.

The problem with doing a pour in sections, is you can only do them so big on your own. About two yards is where I'm comfortable on my own, but I've done three yards and that's pushing it for me. Really pushing it.

Ten by ten and 4 inches thick will be 1 and quarter yards. This is about right for a do it yourselfer to do on your own and get decent results. That means you will have to 12 different pours and tie them all together.

The results will look like a checkerboard and it wont be as strong as a monolithic pour. Each section will be able to move on it's own to a small degree. It will depend on how much rebar you use and what your base material is.

If you put down a few inches of sand underneath it, that would help allot. Sand doesn't move around like clay or other soils.

Then there is the expansion joints. You will have allot of them, but that's up to you weather it's an issue or not.

How will you get your material? You can have it delivererd, or you can pick it up. Either way, there is the shoveling and hauling of it many, many times to get it mixed and poured where you want it.

Doing some simple math and you might realize your not saving that much money by doing it yourself. I'm about as cheap as they come and for something like that, I always hire it done. It's ALLOT cheaper in the long run.

Eddie

 

[MrJimi]

I had a 2500 square foot slab poured, it took a little over 50 cubic yards and I paid the guys $800. to prep and grade and level and finish the concrete. I am very happy with it.
If you use your 8 CF mixer it will take you a very long time and may look like a tile floor ( bunch of small squares )
I did not want to pay all that money out but I believe in
Its cheaper to do it right once then twice halfway.
Something to consider
One cubic yard is 27 cubic feet divided by 8 cubic feet? Hmm
I would not attempt it.
I wish I could give you some good news but its going to be a huge job.

Jim

 

[scesnick]

That is what I figured. I will need 15 yards of concrete for my 1200 sq ft. floor. I have already had a few estimates. one guy gave me a price of $0.65 a sq ft. which is $780 for labor only and $106 a yard for the concrete which is $1,590. which all equals $2,370. So I'm guessing I can get it completley done for around $2,500 Which really isn't that bad.

We are not going to use the rebar or the wire mesh. I think we are just going to go with the fiber in the 3500 lb. concrete @ 4 inches thick.

Mr. Jimi,
WOW !! 50 yards of concrete ?? you must have made that awfully thick? I don't think I need anything that thick.

 

[MrJimi]

Mr. Jimi,
WOW !! 50 yards of concrete ?? you must have made that awfully thick? I don't think I need anything that thick.

Its 6 inches thick at 3,500 PSI and I can put anything on it I want and I have the 6 X 6, 10 gage wire in it. Another good investment. Make sure you put down a vapor barrier before concrete.
I have another 17 Cubic yards for the footer
Jim

 

[AlanB]

Just a thought on the comment as to if you need it that thick, or if you need the mesh AND the wire, or do you need rebar.

All that stuff is really CHEAP, WHEN you are doing it. After the pour, if you have problems with cracking, or decide you want to do something heavier, or something else changes, it is impossible to go back and have a mulligan.

Personally, I would rather spend the money up front and do it all, then to have to deal for years with a floor I was unhappy with.

 

[scesnick]

Alan,

4" is the going thickness in my area. I know next to nothing about concrete except that it is very hard. All the contractors I have had come to the house and look at the project have said that the fiber in the 3500 lb concrete will be plenty. Maybe it has to do with the surface under the floor. Not sure but now you have me wondering ????

 

[Paddy]

There is a big diff in 4" slab vs. a 6" slab. The 6" will likely never crack. The 4" slab can be as thin as 3" if the prep work is not absolutly perfect.

For a pole barn, I would not be to concerned but, for an indoor attached garage I go 6" with wire.

 

[MrJimi]

I played with a calculator and you will need 399.6 cubic feet of concrete divided by 8 equals 50 loads ( 49.85 )in your mixer, are you ready for this?
Its much nicer to watch someone else do it and like you said, you don't know much about concrete, I don't either. It is not a product to practice with, it will harden up and its done.
We don't want to make you wonder, we just want you to have a floor to be proud of for many years to come and don't forget to put the kids hand prints in it.
Jim

 

[AlanB]

4" is certainly the standard throughout that I am aware of. And actually I guess it is usually 3 1/2" because a 2 X 4 is used.

Certainly that is what most folks will quote, it is certainly well within spec, and will do the job.

Ask your buddies with garages etc, and look at their floors. I am betting you will find one that has a cracked floor that the guy is unhappy about. Maybe it is right in the wrong place etc. Maybe it settled, maybe they did a poor job pouring it etc. etc.

I guess my point would be, you only get one shot. You can not effectively or efficiently go back in and add crap to concrete once it is done.

It is the "Base" of many workshops and can really have an impact on how happy you are with it.

Lets say you skimp a bit, and go with an interior door on the exterior of the building,,, you got a great deal on it and you think it will be ok with paint. 6 months later it looks like crap and is falling down, you change it.

Now lets say you go to the standard and just do the minimum required on your floor. Comes out well. Then you decide to do something, lets say bend a bucket straight working against your floor and it cracks or shifts.... Most of us, just have to deal with it at that point as there are few (if any really) good and effective fixes.

Just food for thought before you start your pour. Lord knows there are plenty of shops with a 4" floor.