Concrete quoted... now questions & tips

[Zogman]

I'm in the grading process of the construction of my 2450 square foot garage. I just received my first quoted and I'm rather shocked at the price. Looks like it is recommended to do 2 pours. 1 for the slab and 1 for the curbs that the walls will sit on. Below is the info on the quote.

* Footings & Pad footings
* Concrete curbs
* 5" slab on grad
* 4500 psi concrete
$38,500

So in getting any future bids on this project, would it be best for me to have them itemize the bid out? Like rebar, concrete, pumping and such so I see where all the costs are?

Any tips would be appreciated.
Thanks
Zoli

 

[porschedude996TT]

Ouch!

 

[Zogman]

My sentiments are the same!!!

 

[gpflepsen]

What are the dimensions? I'll assume 40x60...

In my area, 42"x12" trench footing with 12" framing sill= $8400. ($42/ft)

Slab, 5" 3500 psi, #4 bar tied on 2' centers = $10,800 ($4.28/sqft)

Your location is undoubtedly more expensive, but then again, labor cost have to be reasonable.

Why are you spec'ing 4500 psi concrete? 3500 psi should be plenty strong. Highways are usually 4000 psi and bridge deck mix is typically 4500 psi. Admixture cost really adds up and I'm sure they are concerned about the slab getting away from them. 4500 psi is much more difficult to manage for a typical finished slab because of the speed in which the initial set will come. That may explain the two pour approach. 4500 psi seems unnecessary unless you have a specific need. I'd expect a crew to do this pour in one shot.

Can you back a truck in and avoid the pump cost?

 

[deter]

get another quote or two

 

[mbatarga]

My 38' X 60' pad with 18" deep footings, 4" pad, 4k psi with fiber was <$10k

 

[Zogman]

The garage is a 50 x 70 "L" shape that is 27' deep. The reason for 4500 psi is that I plan on having 3 lifts and if I remember right they need 4,000 psi concrete and my architect bumped it up a bit. Is that overkill??? I'm pretty sure I can get a truck back to where the shop is. I do plan on getting a few more quotes. Something tells me this guy see's that I live in a gated community which means that I must be rich. Thanks

 

[rray37375]

Grading of the site, digging footings, installing rebar and mesh, and finishing a rather modest garage slab of 30' x 24' with a 30 x 10' ramp with 3500 fiber mesh concrete at my mountaintop Tennessee home only cost me $9000. Quadrupling the costs for you for the size of your garage from my figures brings your quoted price right about what the contractor quoted you. I had to put both wire and fiber in the concrete to satisfy the inspector, seems that (naturally) the mountains are in a seismic zone and the additional materials are required for construction in such a zone. Concrete is pricey stuff!

 

[gpflepsen]

I'd enhance the slab where you plan the lifts, i.e. increase the thickness to 8" under the area of the lift, say 4'x16'. This is to increase the cracking resistance where the slab will be drilled for anchors. Go with the recommended concrete strength by the lift manufacturer, as they are specifying the anchors to use and that ties directly into the anchor forces and strength of concrete required. I haven't seen one recommend over 3500 psi.

What is important is controlling the cracks so they don't run close or through the post area. Be smart with the control joints and thicken the slab in the post area. Oh, and re-bar at lease in this area.

A thicker slab in the right area(s) is way cheaper than a more expensive concrete mix. And I want no chance of post or slab movement in my shop. That is my plan anyway.

 

[ybnormal70]

Damn! My entire garage 30'x75'x12' with concrete and everything together was less than $40k. I only have 4" and 4000psi that I had tested and it tested at 6000psi .

Kevin

 

[justin1795]

buddy did a 40 by 53 or somthing with drains and heated floors. had one bay extra thick and another set up for the hoist. think he was at about 10,000

 

[Nicholas]

Where are you located In so cal? Reason I ask is I'm a general in so cal and I may be able to give you a recommendation of a concrete guy depending on your location.

 

[Daedalus]

The garage is a 50 x 70 "L" shape that is 27' deep. The reason for 4500 psi is that I plan on having 3 lifts and if I remember right they need 4,000 psi concrete and my architect bumped it up a bit. Is that overkill??? I'm pretty sure I can get a truck back to where the shop is. I do plan on getting a few more quotes. Something tells me this guy see's that I live in a gated community which means that I must be rich. Thanks

You live in a gated community in socal that would allow that big a garage...yeah, you probably are rich. Sounds like a pretty impressive plan, be sure to document the progress with pics here so we can all dream and drool.

 

[NUTTSGT]

The floor alone is 38 yards, I'm not sure what the specs are for the foundation but what is concrete a yard price in your area ? I'm guessing you also need to have extra **** in the concrete whether it be rebar/wire or anchors because of California being earthquake prone.

That might add extra cost but I'm guessing (unless you get multiple quotes) you're paying a premium for living where you do and putting up a huge garage. Is the contractor going to charge you an arm/leg and then going to defray his cost by using day laborers ?

 

[Zogman]

I live in Lake Elsinore Nicholas. Please pass on a good contractor if you know of one you can recommend.

I do plan on taking plenty of pictures and hopefully have a nice post for y'all when I finish up. But this is my first rodeo so this may take a while. I am taking my time and making sure this does not become a nightmare.

 

[theoldwizard1]

If you are spec'ing special concrete (4,500 psi) how are you going to validate that you are getting what you pay for ?

Double check with the architect and the concrete company about the 4,000 vs. 4,500 spec and cost.

I would also be careful about inspecting the forms and the grading to make sure you are getting a full 5" pour ! It is real easy to lose an inch in places. Tell the foreman you plan on checking it yourself or be present when they check it.

 

[Chitown_hillbilly]

Man I wish concrete was a cheap as some of you get it for! The pad for my garage was 1200 sq ft and 5" thick and I did all the work except pour, finish and cut. And it was $4300. I had multiple quotes and the most was $6000.

With as big as this garage is and all the labor involved I don't think the first quote is that far off.

 

[Stevie-Ray]

I agree with getting a few more quotes. My garage is less than half your size, (24x48) but I paid $12.5K for the entire build including concrete. Project price, kit from Menards included, was less than $22K.

 

[polexican23]

Oh Chitown, dont say that!!! I need to pour mine soon and it will probably only be a 20x24

 

[jpinca]

Seems a little high. I think I paid ~$20k for a similar pour in NorCal.

 

[Zogman]

Thanks for the info guys. Really appreciate it!!!

 

[ybnormal70]

If you are spec'ing special concrete (4,500 psi) how are you going to validate that you are getting what you pay for ?


For my concrete I wanted 4000psi and I hired S&ME to be here for the pour and to take test cylinders of the concrete and test it. I have my results back from all the different test they did over a several month period and mine came back at almost 6000psi after I think 56days. They also came and did soil compaction tests before the pour to make sure the site was prepped well.

L8r,

Kevin

P.S.
Testing at 7 days tested at 3990
28 days tested at 5290
56 days tested at 5680

 

[PetesPonies]

Just for point of reference. I put up a 56 x 64 shop. I used a Bobcat to bring in over 350 loads of sandy soil to level. It was not perfect, but in the ballpark. I hired a concrete guy. He leveled and used a vibrating tamper. He installed wire throughout, then poured the slab, with joints and keyways. I paid him and all materials . . . . . and it totaled right at $10,000. So I have $10K total in a slab a lot larger than yours. I do not have a footer. But still . . . . . .