slab cost

[astidham]

Does anyone have an idea about cost per square foot for a slab?  I know that they differ greatly from state to state.
Im am looking at getting a 20x38 slab poured with footings on a. Dozed flat surface, and im getting estimates form 3500.00 to 13000.00 
Im very confused by the huge price difference. 
1 yard cost 80 dollars here currently.

Thanks,
Todd

[astidham]

anyone?

[Redoverfarm]

Todd what is the demensions of your footing.  Will it be a monolithic pour?  What is the estimate on the thickness of your slab? Gravel included? Plumbing included?  Does the price include site prep?  Just a few to get an accurate amount. 

[Squirl]

13,000 is crazy.

Rough estimate.

20x38x 4 inches thick = 10 yards of concrete = $800

116 linear feet of footing at 12"x12" = 4.5 yards of concrete = $360

12 pieces #4 - 20' rebar for footing = $100

24- J-bolts = $50

1 roll remesh = $110

1 load crushed gravel base = $300

Insulation, Plumbing?

Materials  ~= $1800

Other costs
All can be highly locally dependent.
Tamper + Power Trowel + Forms + 1 day for form setup + Insurance + 3 people to smooth and trowel + profit for risk of being in business + taxes

This is for a very simple garage type slab.  A house with plumbing, insulation, and moisture barrier would probably cost more.

[astidham]

Thanks for replying!
I had the area that the slab will go bulldozed a month or so ago, so the site is reasonably flat.
the footings would need to be 16" deep to be below frost depth, and 16" to 18" wide. there will be no plumbing in the slab, and im not sure about the gravel.
the slab thickness I have been quoted for is 4". one contractor estimated 21.00 a foot for footings which includes digging and rebar, then $1.00 a square foot to pour the slab, i pay for materials.
another guy said he will do it for 15.00 a square foot turnkey

Squirl. thanks for the break down!
I think originaly, going through the bidding process is why i put my house on post and pier.

[Patrick]

Mine was 20x40 they removed the topsoil and enough dirt to fill one truck brought in 1 load of sand slab was 6" in center with 12x24 perimeter footing with 2 rows of rebar then rebar crossing every 6' and 6x6 on top one course of 8" block and they poured a driveway/apron combo connecting 2 garages together odd shape but approx 12x20 they brought in a load of class 5 for this polished and sealed the 20x40 portion all for 8100.00 twin cities of MN approx 6 years ago.All the concrete people I know are booked into next year so Im sure that will affect pricing But I just had 7.5 yards delivered was about 900 delivered on a saturday for footing mix.

[walkabout]

Although not to the same scale as a house slab, I just had a slab pored for my shed/garage this month in Minnesota (50 miles west of the twin cities).


For a :

• 10x18 6" slab
  1 row of 6" block
  re-bar
  2' footings around perimeter
  I pulled the permit, subcontractor was around for inspection

if cost me $1,950 or around $11/sqft

I can concur with Patrick, in that I found it extremely difficult to even get contractors to return my calls, let alone bid. They have so much work going on, and I suppose my small slab was not worthwhile for them. In the end I went with the first recommended contractor that returned my calls/emails.

The 20x27 cabin slab and crawlspace walls cost me $9,200 3 years ago:

• 20" x 8" concrete footings with 2 - #4 grade 60 rebar continuous, tied, lapped and elevated.
• 10 courses 12" modular block
• 4" slab
• sump install
• drain tile etc

OR $17sqft

[Squirl]

Part of the reason I rented the equipment and did a block foundation was because it was an easy diy and I didn't have to go through the contracting process.

I do like slabs. Setup, pour, and you are done with your floor.  With such a large pour it requires extra hands, preferably with experience.  I have researched this for a few year for when I want to do my garage.  I have been looking into pouring 10x10 sections, so that I can do it myself.  My logic is that if I have to put in a control joint for the concrete to break along, why not just put in an isolation joint.  It is commonly done in sidewalks and driveways.

Depending upon your soil and what you are placing on top, 16" wide footings my be larger than what the design requires.

[John Raabe]

Thanks for that careful and informative posting walkabout. I expect that question will be asked again in the future and your information will help future members get a better idea of their options.

Yes, the soil bearing and the number of stories putting loads on the footing will determine it's size. You can often get these dimensions with a call to the inspector or the plan checker.

[astidham]

Thank you for your replies,
I got another bid yesterday, 18" wide x 16" deep footings with 4 half inch rebar sticks,  20x38 slab 12 inches above footings with half inch rebar on 2 foot centers.  8700.00
So about 11.50 a square foot.

[dablack]

It seems a little high to me.  I had my 26x52' slab done for right at 10k.  That was on the side of a hill where my guy had to bring in lots of dirt.  It was a 6' drop from one end of the slab to the other.  That was with a 18" deep perimeter footer and two 12" footers across the 26' length. 

Austin

[astidham]

It seems a little high to me.  I had my 26x52' slab done for right at 10k.  That was on the side of a hill where my guy had to bring in lots of dirt.  It was a 6' drop from one end of the slab to the other.  That was with a 18" deep perimeter footer and two 12" footers across the 26' length. 

Austin

Thanks Austin, I am still looking for estimates right now. hope I find a better one!