Need some concrete footing help

[Western]

I probably will be starting a 30x40 shop in a week or 2. My concrete guy has given me a discounted turn key price for the concrete at $3.75 per foot, or he will have his crew pour and finish for $1.00 per foot and I do all the rest that is needed. Total sq. footage with door ramp is approximately 1320 sq ft..

Savings could be around $1650.

Question, Any ideas on digging the footers with a problem back?? I thought about Ditch witch, since I will have one rented, even possible. ?? corners I'll do by hand. Not a huge job by any means.

The rest of it is no biggy, actually the footings aren't a biggy when your young and have a linebackers back.

Thanks

 

[ashdump]

Do you really need footings? Are you putting up block walls?

 

[Western]

Do you really need footings? Are you putting up block walls?

Yes on the footings, concrete friend is recommending min. of 18"HX9"W. below grade

 

[BruceWard]

How deep and wide are standard footers in your area?

How thick will your slab be?

What materials were included in the bid?

I just had a monolthic slab poured. I had the land prepared and the footers jack hammered out of the rock. The concrete crew came in and formed the outside, spread the gravel, tied the rebar, unrolled and tied the wire mesh, spread the plastic then poured and finished the slab. They spent about 5 man days on prep and 2 on the acutal pour and finish. I paid for all the concrete, gravel, rebar, wire and plastic separate from the crews $1.25 a square foot fee. I spent $2.33 a square foot on materials (concrete, rebar, wire, plastic). This brings my total excluding excavation to $3.58 a square foot.

 

[BruceWard]

Yes on the footings, concrete friend is recommending min. of 18"HX9"W. below grade

9" is pretty wide for a ditch witch. I think you would be better with a backhoe.

My footings where 3' wide and 1' deep underneath the slab which was about 5.5" thick.

 

[CurlyDave]

I have a mathematical question. At 4" thick 1320 sq. ft. is just over 16 yards of concrete, the footers will add more, about 4.5 yards.

I don't believe any contractor could supply concrete, and provide pouring, screeding and finishing labor for $1320. I think he could supply the labor, but 20 yards of concrete is going to cost you about $100/yard, maybe 10 to 20% more.

A concrete contractor may get it for a substantial discount, about $85/ yard, which is still more than the total cost of $1/ft he is asking.

So, I suspect that in the $1/ft scenario, you are going to pay for the concrete. Plus the rebar, plus do all the labor and pay for the form boards. You will pay more for the concrete than he does. Concrete alone will be on the order of $2500. Steel will be about $600 and you will have other expenses along the way. Already we are at $2.35/ft.

Unless you have a rotary laser and experience, you will not be able to level the forms nearly as well as the contractor can.

Essentially, if the $3.75/ foot bid includes materials, it is a real bargain.

You should check for yourself, but I think you will save a lot of work and get a better product by taking his bid.

 

[Western]

I appreciate the input, but Let me try to rephrase my question.

He will do/supply everything, excluding prior dirt work, for the cost of $3.75 per sq. ft. Area is 1320 sq. feet x's $3.75 = $4950

He will supply his crew to come pour and finish for $1.00 sq ft. or $1320 . I would be responsible for forms, steel.

16 yards is what he figured, plus an additional yard, so 17.

$80 a yard for me ($1360+tax), lumber I can use for shelves, and I already have half the steel if not more. I have the know how, just not the back I used to have.

I can rent up to a 12" ditch witch here, 9" is standard (here).

I was thinking possibly a small backhoe or the DW also to help with the majority of the footings, then closing the last end and using my nephew
When we did a public school slab when I was working through college as a steel tier, they used a large excavator, but of course those footings where HUGE.

 

[CurlyDave]

Either a backhoe or an excavator will be much easier for the footings. A ditch witch throws half the dirt to each side, which means half the excavated dirt will be inside your building and have to be removed by hand or by tractor. BH or excavator will place the dirt outside the building.

Have him check calculations again. 1320 sq feet @ 4" depth is 16.3 yards. Poured monolithic, the footers need to be 14" x 9" x 140 ft. This is an additional 4.54 yards.
You will need to order at least 21, probably 22 yards.

* * * * *

What kind of building will the shop be? You need a design if it requires foundation bolts or seismic tie-downs. These go in during the pour and woe be unto him who does not have them in the correct places. Where your mudsills splice together, you need two foundation bolts no more than 1' from the end of each. I prefer about 6" from the end. Don't forget the corners where you again need a foundation bolt no more than 1' from the end of each mudsill.

You need a Eufer rod for grounding an electrical panel, right under where the panel will be.

 

[Duffster]

I appreciate the input, but Let me try to rephrase my question.

He will do/supply everything, excluding prior dirt work, for the cost of $3.75 per sq. ft. Area is 1320 sq. feet x's $3.75 = $4950

He will supply his crew to come pour and finish for $1.00 sq ft. or $1320 . I would be responsible for forms, steel.

16 yards is what he figured, plus an additional yard, so 17.

$80 a yard for me ($1360+tax), lumber I can use for shelves, and I already have half the steel if not more. I have the know how, just not the back I used to have.

I can rent up to a 12" ditch witch here, 9" is standard (here).

I was thinking possibly a small backhoe or the DW also to help with the majority of the footings, then closing the last end and using my nephew
When we did a public school slab when I was working through college as a steel tier, they used a large excavator, but of course those footings where HUGE.

As many time as you have mentioned your back already I am not sure why you are even considering doing this yourself.

 

[bigtiller]

As many time as you have mentioned your back already I am not sure why you are even considering doing this yourself.

You beat me to it Duffster. With a bad back, the only bending over I would do is to pick up the check book.