How many wheelbarrows for a yard of concrete?

[alvinamorey]

I will be having a delivery this week of concrete. I am getting 3.25 yards. Two and a quarter yards will make a 9 x 20 foot driveway extension in front of my garage. The other yard will go into a nearby shed to make a cement floor to replace the dirt floor, which is 6 X 12 ft., plus a small pad outside the door from whatever is left.

For the driveway extension the truck can drive right to it. But the shed is not accessible by truck. That one yard needs to be taken into the shed with wheelbarrows. I am trying to comprehend how many (average size) wheelbarrow trips will have to be made to carry that one yard to the shed. I am asking to get a rough idea so I know how many friends and wheelbarrows to have on hand. The delivery company said that their delivery guys cant spend a lot of time at one place, so I need to be ready to get the cement moved fast.

I know someone is going to ask me what I mean by average size wheelbarrow. I dont know how they are rated, but the two that I have are the ones sold at most garden supply places, department and hardware stores for the average homeowner. My guess is the "bucket" is about 28" wide, 35" long, and 10" deep (of course the corners are rounded and the bucket tapers in at the bottom.

My guess (and only a guess), is one wheelbarrow load can hold about

2.5 cubic feet, (without spilling all over the place), and a full yard of concrete is 27 cubic feet. So my guess is about 11 trips. Does this sound about right?

One other thing. Since I plan to use whatever concrete is left over to make a pad in front of the shed door, outside, what is the best way to make an adjustible form? My idea is to make the form the actual width I want (which is 41"), then just leave the end board (away from the door) without nails or stakes, so I can fasten it after the cement is there and I know how much cement is left. If by chance the pad seems too small, I have a few bags of redi-crete to use up, so I can mix them.

Thanks

Alvin

[DerbyDad03]

Any chance of the delivery company using a boom truck to deliver the concrete directly to where the shed will be or is that way too expensive for this size job?

[RicodJour]

Fill it with five gallon buckets of water. Count the buckets. Do an online conversion from gallons to volume, tweak to get cubic yards.

Maybe. Homeowner wheelbarrows are in that neighborhood, maybe slightly more. Contractor wheelbarrows hold about 6 CF.

Fine.

R

[beecrofter]

I always guessed 2 tons per yard. And 300lbs is about all I want to hump around in a wheelbarrow. 13-14 trips

[DerbyDad03]

Oh, sorry, forgot to offer an answer to your question...

From:

"One cubic yard of ready-mix yields nine contractor-size wheelbarrows of concrete. "

From:

"A construction wheelbarrow full of concrete can weigh nearly 400 pounds."

AFAIK a contractor's wheelbarrow is roughly 6 Cu ft. Since your's appear to be much smaller, 11 trips seems too few. Of course, it also depends on how much weight a person and or a given wheelbarrow can handle.

Actually, what you want to use is the 2 wheeled, spout nosed wheelbarrow shown on page 2 of this document. Look for the red NEW! graphic.

Here's a "fun" site for estimating the cost of concrete construction, including info moving material in wheelbarrows. This link should take you to page 553 - ignore the references to horse drawn carts, but pay close attention to the comparison of "active" vs. "lazy" workers. ;-)

[RedRover]

How much is a boom truck option?

[DerbyDad03]

-- How much is a boom truck option?

$20.00...No wait...$200....No wait...$2000... ;-)

Where do you live? How long of a boom do you need? What will be the travel time from the plant to the delivery point? Are there any road restrictions/usage permits that will need to be dealt with?

See my point? My guess is that the cost of the boom option would be highly dependent on the specific job. I'll also hazard a guess and say that using that option for a 3.25 yard load would be cost prohibitive.

[Harry K]

First; Unless you have wheeled mud before, do not fill the barrow full. Even if you have, do not fill the barrow full. Better several extra trips than spilling a load. Concrete is _heavy_.

Second: Be sure the path to the shed is smooth and firm. If needed, lay down sheets of plywood overlapped so the loaded barrows don't run into the 'lap'.

Harry K

[Dan Espen]

Go out and measure it. Take the width and length at the bottom.

A cubic yard is 36x36x36

My guess is you can only fill to about 6 inches of the 10.

Roughly 10 trips without the math. When you have the measurements divide

width times height times depth into 36x36x36.

Don't assume to can use the whole depth.

[Larry Bud]

No offense, but has basic math skills gone out the window so that you have to guess?

One yard is 36x36x36"=46656 cubic inches If your bucket is 28x35x10, that's 9800 cubic inces

46656/9800=4.76

IOW, 5 trips.

[DerbyDad03]

Math is our friend...I'm not doubtin' your numbers, just trying my own. Let me know if I missed something...it's Monday.

As I posted earlier from:

"One cubic yard of ready-mix yields nine contractor-size wheelbarrows of concrete. "

AFAIK a contractor's wheelbarrow is ~ 6 cu ft and the OP's is estimated (by him) to be only 2.5 cu ft.

Now, if I do a little math and divide 1 cu yd by 6 cu ft I get

27 / 6 = 4.5 (not nine) which means they are only putting 3 cu ft in each wheelbarrow - IOW - half full.

Therefore, if the OP puts only 2 cu ft into his 2.25 cu ft wheelbarrow, it's going to take at least 13.5 loads. If he follows the lead of the DIY site and only fills his wheelbarrow half way, it's going to take 18 loads.

Does that sound right?

[Joe]

But keep the truck off your driveway unless you like cracked concrete. He might make ruts in the lawn, but in a few months they will disappear. Have lots of helpers available, don't forget to compact the soil and use pea gravel and wire mesh/rebar. Good luck.

Joe

[Pat]

Just for the record, I've never heard of anyone ordering 3.25 yards. I don't think they make/transport concrete in that level of precision

-- esp. to the second decimal place. So don't plan your needs too closely.

[HeyBub]

Whatever results you come up with, double them. It's far, far better to have too many helpers than too few. For example, what happens when one (or more) of the volunteer wheelbarrows breaks? Or for that matter, when one of your helpers keels over with a heart attack? What happens if it rains? Helpers are cheap (pizza and beer).

Lay a plywood track to the dumping area.

You'll need barrow drivers and concrete spreaders. Have plenty of tools on hand (shovels, hoes, etc.).

Your plan for an adjustable form sounds fine. Be sure to put in reinforcing (rebar, wire mesh...)

[DerbyDad03]

re: what happens...when one of your helpers keels over with a heart attack?

Wouldn't you need less concrete?

[Don Klipstein]

A 35 by 28 by 10 half-ellipsoid is 2.97 cubic feet, and in my experience wheelbarrows are a little closer to conical than to that. A cone (elliptical version as opposed to circular) of the same dimensions is 1.9 cubic feet. I would guess about 2.2-2.3 cubic feet.

Meanwhile, suppose the actual inside dimensions are 33 by 26.5 by 9.5? That's 15% less volume! Sounds to me like 1.9 to 2 cubic feet now.

Another point - that wheelbarrow will not be level during the filling and the transportation. I think it would be optimistic to fill it 1 inch short of the top, and I think 33 by 26.5 by 9.5 then becomes at best 31 by

24.5 by 8.5, and that's with optimistic aggressive filling of the wheelbarrow. That makes the volume 66% of the original figure (of 2.2-2.3 cubic feet), meaning about 1.5 cubic feet. Make that 1.6, because that portion of the wheelbarrow gets a little closer to a half-ellipsoid and a little less like a cone. But this is still with filling the wheelbarrows so full that you have a good chance of spilling concrete. I think more realistic is fill it 1.5-2 inches short of the top, roughly 1.3 cubic feet of concrete. A cubic yard is 20-21 wheelbarrow loads at that rate. I may be erring a bit on the conservative side - please post your actual results!

Now, another matter: How much weight to pour into a wheelbarrow? Although the wheelbarrow operator only has to lift about 40% maybe 35% of the weight of the wheelbarrow and the load, keep in mind how much a cubic foot of concrete weighs. I asked a concrete mixer driver how much concrete by cubic yards and tons his truck carries, and IIRC the answer was 10 cubic yards and 20 tons - meaning a density of 2 tons per cubic yard. I have read a few slightly lesser figures however. A ton per cubic yard is 148 pounds per cubic foot. The Wikipedia article on concrete says that the density is usually around 150 pounds per cubic foot.

My experience suggests that if someone has to carry much over about 100 pounds, there is a good chance that things get wobbly. Beer goes only so far to buy careful driving at best! I am guessing that it takes 10 pounds of force to lift the handles of an empty wheelbarrow of above size, leaving 90 pounds divided by the 35-40% above that I am guesstimating for percentage of weight showing up at the handles. That means 225-257 pounds of concrete. Divide by the Wiki figure of 150 pounds per cubic foot, and that is 1.5-1.7 cubic feet.

At this moment, I would say probably 1.3 to 1.5 cubic feet per wheelbarrow load, 18 to 21 wheelbarrow loads. Though I would not be too surprised if everyone manages a "good mood chemistry" and gets it done in

15 trips - but be prepared for things to not work quite that well and require closer to 20 trips.

Be prepared to accept the concrete delivery in a timely manner, especially if you are not the last stop for the concrete truck. The driver does need to empty the truck before the concrete hardens, and concrete does not need air to harden. Concrete cures from the cement ingredient (typically "Portland Cement") combining with water to form a rock-like hydrated material. Maybe even if you are the last stop the truck still needs to keep rolling on a schedule - I suspect the truck may need to be rinsed out before the residue hardens! (They say "cures" in that industry.)

Another thing that may help a little, at least gain a "brownie point", when dealing with concrete people: Don't refer to concrete as cement. Cement is the adhesive component of concrete. Cement roughly means glue! Concrete is a mixture of cement, "fine aggregate" (traditionally sand), and "coarse agregate" (this is often pebbles). The basis for this is that most of the volume is pebbles with sand grains filling much of the space between the pebbles, and pebbles and sand cost a lot less than cement does.

- Don Klipstein ( [e-mail])

[Dan Espen]

Maybe, but I didn't do any math. I looked at the OPs numbers, saw he was just under 36 on the length

1/4 under on the width and 1/6th on the height and that sounded like about 10. Give or take a few.

Why do math when the OP doesn't have accurate measurements to start with?

[DerbyDad03]

re: Maybe, but I didn't do any math.

I guess there are varying degrees of "doing the math". :-)

Seems to me that you can't "see" that he was fractions under a number without do some sort of math. If I "see" you get served a steak that is twice as big as mine, then I did some math just before I called server over to our table.

You gonna eat that potato?

[Rudy]

NO ! Its $ 300 minimum charge PLUS time for a line pump/boom here

USE the 3 or 4 wheelbarrow method

[aemeijers]

Snip

Having pushed a wheelbarrow or three hundred as a kid- volume isn't as important as weight. Wet concrete weighs like a bitch- it would take superman to push a full-size wheelbarrow of it, especially since we are usually talking pushing it on dirt or bouncy walkboards. A full one would usually lose the top 3-4 inches of fill to splashing. If you are filling the wheelbarrows out of a truck or portable mixer, more important to have many strong backs and several wheelbarrows staged. You only have so many minutes of 'open' time before you have to dump the load Right There, rather than in the forms. Once the concrete shows up, IT is in charge- no smoke breaks, no lunch, no potty breaks. You move and shovel and screed till the forms are filled.

Back before concrete pumpers came along, they used to have cute little self-dumping gas-powered walk-behind 'mules' for use on sites where you couldn't get the truck close enough.

aem sends...