I’m getting ready to order my concrete for a retaining wall and I was wondering if there was a rule of thumb for how much to order. That is, it seems to make sense to have more than you need than not enough, so do you order more as a precaution, and if so how much? Also what do you do with the stuff you don’t use? I’d appreciate any insight on this….
John
Replies
John
I can order by the 1/4 yard from my supplier. So if I need 4.8 yards I will order 5. If I need 5 yards I will still order 5-1/4. I would rather be heavy than light on my pour. If you are using forms you should be able to calculate very closely what you need.
My supplier takes back any concrete left in the truck back to the plant to be recycled. Concrete ingredients are measured by weight not volume at the plant before mixing. Sometimes you get exactly 5 yards sometimes you get a little more or less. The plants here are really good about getting you what you need. Hope this helps
Mark
Thanks! -- thats all I needed to know...
order 1/2 yard more than you need and do not look in the back of th etruck when you done. let the driver take it with him.
I always have some forms available so that I can use the extra concrete that I've paid for. 2'x2'x 3" concrete pads are useful, so I keep those forms available. Also find 10" diameter x 6" high circular pads handy for deck building, so I keep lots of drywall buckets available and fill them with about 6" of concrete. Though some of the castings get stored for a year or two, I still end up using them all.
Order 1/2 yard more? Geez, I'd rather put the money in my pocket by measuring tighter.
Randy
Edited 11/1/2006 7:57 pm ET by Reg
because if you run short and have to order a 1/4 more, its a two yard minimum
Here they take the excess back to the plant and pour lock blocks.
Always better to have a bit more than you need!
They do those blocks here too, but it's at my expense if I over-order. I measure carefully and add between 1/2 and 1 yard. I only go 1 yard over if the excavation is rough and there's going to be squeeze-out all over the place.
Don't forget to feed the pump. The boom we usually use here eats half a yard.
I've had good luck figuring the amount of concrete by rounding up to whole numbers for calculations, adding 10% and rounding up to the nearest 1/2 yard. This is the formula we use for almost all jobs.
Fastfoot, a fabric footer form has a great deal of variability as the fabric pooches out and the tops bow out so we use a 15% fudge factor, but it's rare to need that much reserve with normal forms.
If using a pump truck I'll add 1/2 yard, although they will tell you it only takes 1/4 yard. Too many times we'll have a series of clogs that results in mud everywhere as they take the hammer to the hose over and over.
Two weeks ago an estimated 31 yard pour actually used 30.
The week before I had my first short order on a very simple project. Our footers were figured to 7-1/2 yards and the pour was slightly under 1 yard short. A quick recheck and I said they sent 6-1/2 yards not 7-1/2, but it didn't get me far and we paid for another truck to bring one whole yard. After rechecking the numbers and reconsidering the amount of form movement I'm confident it would be impossible to fit 8 yards in the forms which were extreamly straight and uniform for footer forms. Other contractors have had similar complaints lately so it seems that it's good to double check what shows up and question loads that don't seem right.
Beer was created so carpenters wouldn't rule the world.
Our batch plant works with volume and weight. If your forms are nice and flat, and the ground below the footing is smooth, you shoulld be able to get an exact amount, but if your numbers and the batch plants numbers don't jive, you lose and pay for the shortage. At $150.00 per CY here, i don't like to see the plany take any of it away, but they always do. It's like the baseball manager complaning about a bad call, the guy in the stiped shirt wins, no matter who was right!