Insane prices for additional concrete

[globalmax]

I had a thread a while back to prep the garage floor for a two post lift. Thanks for everyone's input.

Garage Build Concrete floor - Should I know the For 2 post lifts dimensions in advance?

In the process of finalizing house and garage plans. I understand the need to have reinforced concrete floor or two posts lifts. My plans are to put a 2 post lift in my garage at a later point but not decided on which one. So not sure about the exact dimensions. What is the general...

www.garagejournal.com

General consensus was to go from 4" to 6" thick concrete floor for the entire 25x 30 garage. Additional 2 inches which will be 4.63 yards of concrete.
I was thinking that approximate $150 or so per cubic yard for concreate which could be a total of approximate $600 to $700 maximum.

Garage is part of the overall home build considering 4" concrete garage floors. The quote I got for additional 2 inches of concrete is $2500 !!!. Does additional 2" of concreate involve so much additional labor, what am I missing? Guess he is mixing gold hence this price

 

[Spareparts]

If it takes 2 trucks for the total pour the second truck would be a short load and that gets expensive

 

[globalmax]

If it takes 2 trucks for the total pour the second truck would be a short load and that gets expensive

Even if that is the case, they are building a house and there are more spaces to put concrete from the second truck

 

[readhead]

Extra excavation, taller forms equals more labor plus the extra concrete.

 

[luvtheheat]

I recently built a 24' X 44' detached garage. Garage door was to be 8' high. Got concrete floor work estimated at that. 4" pour. Changed my mind and went with 10' garage door.

That change forced a change in the rebar work (to what they called an "engineered footer") and a 5" pour, and slab work alone went up by probably $10-12K. The brickwork also increased sharply, which is easier to understand as walls height went up 25%.

 

[The Cobbler]

If it takes 2 trucks for the total pour the second truck would be a short load and that gets expensive

not here, maybe a regional thing. if we need 1 meter over a truck load, the second truck has no under load if you order it at the same time. but if you end up short on your calculations and need another meter without asking for plus, you're going to pay an under load .
if you're close to a full truck and order 9meters plus , you can order more with no underload... but the you're going to wait for the next load & that's not good maybe

 

[Rusted Nut]

No short load on a second truck here the PNW. If no other work required (forming, grading, etc..), then cost should really only about $300 for concrete. No real added labor for pouring 6” vs. 4”.

 

[TRWham]

Deleted as based on a misreading of the OP.

 

[C-S-H]

A 6" slab is pitifully thin for use under your 2-post lift, and overkill for the rest of the slab for light vehicle loads. Why not just thicken the slab where it needs the strength? This practice is commonplace in civil construction. Reinforce the thickened portion of the slab correctly using the 2-post lift manufacturers' literature for guidance.

 

[Slick111]

Stay with the 4 inch pour except do a thicker trench area where you will put the lift

 

[bb29510]

four all you need and required for most lifts, get a four post and dont worry about it

 

[pcmeiners]

"Does additional 2" of concrete involve so much additional labor, what am I missing?"

Your not missing anything. But the contractor would be missing a chance at making a nice bit of profit on 2" of concrete.
As is the slab will need 9.2 yards at 4", that is with NO spare/waste concrete, so he really needs 10 yards, a second truck anyway. $1300 at most,considering an extra hour for the pour, and a smaller profit; $2500 if he is mixing some gold leaf sprinkles so that you concrete has tiny sparkles with the lights on.

Then again your into the season where contractors are booked solid, so highway robbery is legal.

 

[globalmax]

Not too sure about additional truck for this extra 2 inches is driving up the cost.
To give some more context, contractor is building the whole house and I am sure he is not bringing the truck for putting concrete on just garage only. Agree that I just can't consider the cost for 4.63 cubic yard of concrete and everyone needs mark up.... but this is something I don't understand

 

[BombShelter]

I haven't sold concrete flatwork for over 10 years but back when I quoted it the boss just wanted me to go a little over the yard pricing for the extra thickness. We typically went 5" on anything with vehicles and 4" on sidewalks.

 

[PCustoms]

Not too sure about additional truck for this extra 2 inches is driving up the cost.
To give some more context, contractor is building the whole house and I am sure he is not bringing the truck for putting concrete on just garage only. Agree that I just can't consider the cost for 4.63 cubic yard of concrete and everyone needs mark up.... but this is something I don't understand

He sure as hell isn't bringing in the truck for footings, walls and slabs on the same day.

He's probably breaking up the pours into footings, walls and slabs, possibly separating out the garage due to size and finishing.

Maybe ask him why it's so much?

 

[Leaflessshadetree]

Had a contractor tell me that he always charges by the yard. 50% more concrete = 50% increase in price.
Same contractor asked me why I DIY.

 

[PCustoms]

Had a contractor tell me that he always charges by the yard. 50% more concrete = 50% increase in price.
Same contractor asked me why I DIY.

Around here an easy estimate for flatwork is 2x $/cuyd

 

[globalmax]

Purely from concrete cost standpoint for 4.63 cubic yards ( say $150 per cubic yard) and whatever additional labor involved to pour down this 2 additional inches, don't think it should be more than $1K even with some mark ups?

 

[bb29510]

its 50% more conctere put the finshers only deal with the top 1/4 inch

 

[Chaznsc]

I had a thread a while back to prep the garage floor for a two post lift. Thanks for everyone's input.

Garage Build Concrete floor - Should I know the For 2 post lifts dimensions in advance?

In the process of finalizing house and garage plans. I understand the need to have reinforced concrete floor or two posts lifts. My plans are to put a 2 post lift in my garage at a later point but not decided on which one. So not sure about the exact dimensions. What is the general...

www.garagejournal.com

General consensus was to go from 4" to 6" thick concrete floor for the entire 25x 30 garage. Additional 2 inches which will be 4.63 yards of concrete.
I was thinking that approximate $150 or so per cubic yard for concreate which could be a total of approximate $600 to $700 maximum.

Garage is part of the overall home build considering 4" concrete garage floors. The quote I got for additional 2 inches of concrete is $2500 !!!. Does additional 2" of concreate involve so much additional labor, what am I missing? Guess he is mixing gold hence this price

It’s excessive. I’d just talk with the guy.

 

[Beemer]

Over forty years in building construction design industry and if there is one set thing learned is that once the contract is signed "additions" to the job are priced like gold.
Most contractors I saw on jobs in the last ten years go in with a low price to get in the door but more than make it up in the coarse of the job. Pricing gets ridiculous.
You might ask for justification of the requote but that might not get you far.
You might look into an independent contractor to come in for the slab but guaranteed you'd get a very small credit for taking the slab out of the original contractors scope. That's how the game is played!

 

[nadogail]

Money is made on the Change Orders, eliminate them if possible or keep them to an absolute minimum.

 

[ItsNemo]

A 6" slab is pitifully thin for use under your 2-post lift, and overkill for the rest of the slab for light vehicle loads. Why not just thicken the slab where it needs the strength? This practice is commonplace in civil construction. Reinforce the thickened portion of the slab correctly using the 2-post lift manufacturers' literature for guidance.

6" is PLENTY for under a 2 post lift, it's more than most manufacturers ask for in fact.

 

[Firebrick43]

Around here an easy estimate for flatwork is 2x $/cuyd

Everyone I have ever hired quoted Sqft prices on placing/finishing.

 

[rayra]

The 'general consensus' had its head up its ***. Just thicken the region where you are placing the lift.

its 50% more conctere put the finshers only deal with the top 1/4 inch

and the forms dont have to be taller, either. But it is more work to handle 50% more material

 

[Sumboodie]

Wow,

Around here an easy estimate for flatwork is 2x $/cuyd

That's cheap!

I've gotten quotes for a 30x30 in the 16-18k area.
Concrete is around $160/yard.

That would be around $2600 and 5100 labor. Maybe another $1500 in rebar, forms, etc, that's barely over 9k.

 

[C-S-H]

6" is PLENTY for under a 2 post lift, it's more than most manufacturers ask for in fact.

No it is not plenty. The manufacturers allow the thinner pre-existing slabs only if reinforced with a highly unprobable amount of reinforcement. So the retrofit slab design is required in every case for 2-post lifts. Having run the design computations on 2-post lifts myself, there is no way the thickened areas of the slab are going to be less than about 8" or 9". Manufacturers require 12".

 

[PCustoms]

No it is not plenty. The manufacturers allow the thinner pre-existing slabs only if reinforced with a highly unprobable amount of reinforcement. So the retrofit slab design is required in every case for 2-post lifts. Having run the design computations on 2-post lifts myself, there is no way the thickened areas of the slab are going to be less than about 8" or 9". Manufacturers require 12".

Source?

 

[C-S-H]

Here are a couple:
Mohawk
Bendpak

 

[ItsNemo]

Here are a couple:
Mohawk
Bendpak

That is when you're retro-fitting an existing slab with a cutout and inset pour, not a new monolithic pour....pre-existing floors 6" is plenty (unless you're doing a 12k+ lift, which rarely people do at home, that's for heavy duty shops), per YOUR links:

 

[NUTTSGT]

Purely from concrete cost standpoint for 4.63 cubic yards ( say $150 per cubic yard) and whatever additional labor involved to pour down this 2 additional inches, don't think it should be more than $1K even with some mark ups?

Probably a $1500 change order.

 

[bb29510]

even with the extra, labor is really minimumal because finisher onlt deal with the top 1/4 inch

 

[Dig Doug]

Adding 2 inches to your slab thickness seems fairly easy & simple

but
depending on build conditions & build plans there could be extra hidden costs that are not visible at 1st -
like grading, & sub grade moving handling materials, extra labor for placing and finishing and possibly pumping, could also be a sub contractor ….

Talk to your builder to see what’s all involved

Keep in mind you’ll have a few of these “ extras/ changes “ during the build process
sometimes you can get a credit back and most times cost a little extra
a give and take so to say



Important part is to maintain a good relationship with the contractor as the slab is in the beginning of the project and there will be a long road until completion

 

[Dig Doug]

Another option would be to go 5 inch Slab

If 6 inch is $2500
would the cost only be $1250 up charge for 50% less concrete than the 6inch slab…..


hmmmm

 

[C-S-H]

That is when you're retro-fitting an existing slab with a cutout and inset pour, not a new monolithic pour....pre-existing floors 6" is plenty (unless you're doing a 12k+ lift, which rarely people do at home, that's for heavy duty shops), per YOUR links:

Why are you ignoring the rebar requirement? Nobody is going to have a pre-existing 4" or 6" slab with #6's at 10" or 12". And no knowledgeable person would cast that design in a new structure. They would hire an engineer to calculate an efficient and reasonable reinforced slab that is strengthened around the lift bases. The 2-post lift industry needs to hire another engineer to calculate their standard concrete requirement sheets. What they have is poor.

 

[Smoker]

Why are you ignoring the rebar requirement? Nobody is going to have a pre-existing 4" or 6" slab with #6's at 10" or 12". And no knowledgeable person would cast that design in a new structure. They would hire an engineer to calculate an efficient and reasonable reinforced slab that is strengthened around the lift bases. The 2-post lift industry needs to hire another engineer to calculate their standard concrete requirement sheets. What they have is poor.

I do. I had them pour the slab to those specs (actually ~5-6" deep to allow for slight changes in fill level) with that rebar on that spacing.

 

[Firebrick43]

Why are you ignoring the rebar requirement? Nobody is going to have a pre-existing 4" or 6" slab with #6's at 10" or 12". And no knowledgeable person would cast that design in a new structure. They would hire an engineer to calculate an efficient and reasonable reinforced slab that is strengthened around the lift bases. The 2-post lift industry needs to hire another engineer to calculate their standard concrete requirement sheets. What they have is poor.

Because we are not talking about a pre existing slab, we are talking about a new pour

 

[globalmax]

Another option would be to go 5 inch Slab

If 6 inch is $2500
would the cost only be $1250 up charge for 50% less concrete than the 6inch slab…..


hmmmm

It is 30 length x25 feet wide 2 bay garage. Lift is going to be on one bay only. Having additional 2 inches of concrete only in one bay is a possibility?

 

[PCustoms]

It is 30 length x25 feet wide 2 bay garage. Lift is going to be on one bay only. Having additional 2 inches of concrete only in one bay is a possibility?

They just dig the grade deeper on that side.

You could also roughly plan out where the lift is going to be, and pour those areas deeper.

 

[finn]

No it is not plenty. The manufacturers allow the thinner pre-existing slabs only if reinforced with a highly unprobable amount of reinforcement. So the retrofit slab design is required in every case for 2-post lifts. Having run the design computations on 2-post lifts myself, there is no way the thickened areas of the slab are going to be less than about 8" or 9". Manufacturers require 12".

I call ******** on this one. The compressive strength of typical 4” thick concrete is 3500 psi, or 504, 000 lb/sf. So double that if you have a two post lift with one square foot pads on each post. Then add normal rebar reinforcement.

Then consider that the slab isn’t hanging in the air like a bridge, but is supported underneath by a compacted gravel base.