I'm trying to estimate how much help I'll need when I pour a 40 foot by 60 foot x 8 inch thick concrete slab with footers and rebar reinforcement.
The biggest slab I've ever poured was 12' by 16' with 3 people and that seemed to keep us pretty busy.
any advice?
It all depends on how well you are set up and prepared.
How wide of a pour are you planning?
How well are your forms leveled and braced?
How well is your base compacted?
Why eight inches thick?
What strength concrete?
Are you planning a pumper to place the concrete?
Do you have a good cement finisher lined up or will you be happy with water standing on the floor?
If you do not have good answers to these questions, best advice would be to hire a local contractor to advise you and do the pour for you. Concrete is very unforgiving and expensive, especially for 60 or more yards.
I'm with Gary on this. Get a pro to place it for you. If you have done the rest of the work, placing and finishing is a small part of the total cost, but a major cost for a pour gone wrong.
Must admit I agree with Lee.
But, if you really are gonna go it alone. Work out how many people you need, then double it.
There's NOTHING worse than the concrete going off before you get a chance to screed it... >:(
(Don't ask how I know...)
asy :D
If you have an experienced crew, 3 people would be plenty. If you do not have experienced finishers, hire it out. You will be glad you did.
Honestly, hire it done. Get someone local who regularly work with the concrete company(ies). Someone who likely knows the drivers so they have a good working relationship with them.
I've poured lots of concrete, and though I've worked and finished some of the smaller slabs myself, the size you're speaking of, I would have absolutely no desire to take on the finishing responsibility without all the necessary equipment and a good, seasoned crew.
A load of mix that's a little hot, etc. can change things to a basic, catastrophic note.
With the price of the concrete, your work in getting your groudwork, etc., done, the price paid for a pouring/finishing crew is the least you could do for yourself.
When you have concrete of that size, when it starts to go wrong, 'praying won't help you, crying won't do you no good'(or, is it the other way around?).
No one appreciates 'do it yourself' more than I. You'll still have plenty to do. ;D
If you really want to do it yourself with a couple helpers split it up into two or three smaller pours. That's a lot of mud to pour and alot of area to finish.
i am like the other do it yourselfers, that is alot of concrete. if you go for it you better have your A game with you that day and start early.
you will start your power trowel on one end about thetime you finnish pouring on the other. i just pored a 14x14 and a 19x 11 in the same day took about 3 hours to complete with 3 guys. then the finnishing started. good luck.
Overhere, I,ve seen on TV (Holmes on Homes , m.Holmes fix houses after a bad contruction or repair) and they were on a big slab, a whole house floor, they used a new cement , a self-leveling cement, it is quiet liquid but drys as other cement , it was self leveling,,,,,,,very nice job.
I just called my cement company and it is true, they call it (*auto nivellant *in french) in english it would translate *SELF LEVELING CEMENT*. so if your exterior frame is at level, pour the cement to the edge and that,s it. call your local distributor and believe me it is not a joke. Good luck Roger
I've got a couple concrete worker friends I can call with some finishing tools. This is for a future under ground home Mandy and I are planning on our property. Its a bit thicker and more reinforced than most pours due to the load everything has to handle.
The mix will be 3500 lbs mix, and unfortunatly it pretty much has to be one big pour :D. I'm currently having an inspector going over my cad drawings and getting ready to rent a high lift for a few days. The plan is to build over an extended length of time (3 years or so) as we get extra cash. I will be hiring out for the wall and retaining wall pour but would like to save some cash by doing the main floor, plumbing runs, electrical stub-ups and future empty piping stubs ourselves.
We poured a similar size slab with
two on the screed
one on the rake
one at the chute (Tell the trucker to stay in the truck and drive.)
one moving rebar mats.
The pour was split into three sections lengthwise, the rebar left out of the middle as a driving lane.
back the truck to the far end and pour one side, back the truck up and pour the other side. As the truck travels out third time the mats can then be placed and pour down the middle. I pre welded the mats into 2x2 grids that were 12 feet on a side if I recall.
Elevations were shot with a transit and 1 x 4 rails on pegs for screeding on. was extremely accurate and removed after the pour and before it stiffened.
Put poly under the slab it stops the moisture from migrating into the soil and not hydrating the reaction. Makes for a much slower set and much better concrete.
Two of us finished with power trowels two doing the edges by hand and one cutting the joints. If it is hot or windy use a sprayer and a mix of half and half linseed oil and diesel to stop evaporation after you are done finishing.
one went for beer and rum. CAUTION!!! not to be cracked open till the slab is DONE!!!
I would love to come play but too far!
Modat, forgot to look at your age. When I was young, I could do a lot by myself. But if you don't pour concrete every day, or at least every week, you just don't know how to handle it effectively. Me, I would figure out how to pour the footings, and then cut the pour up into parts. Probably at least 4. A 10 by 60 is a lot of concrete to pour and finish, even with 2 guys. Especially if you don't pour concrete regularly. My plan when I do my shed is to do a 12 x 63, and probably one of those a week. Need to recover from one before I do another. Thing is, how are you going to set your grade on a monster slab. I know pros who would do the grade off about 3 pieces of rebar, then screed off the wet concrete. Me, I'd prefer to set forms, or at least pipes and slide them as I went along. Really isn't a bad thing to pour it in parts, creates natural cuts, so the whole slab won't get a big nasty crack. Has control joints built in.
alot of good points, I need to do some consultion on my plans. I admit that I was in the mind to just go do it my way no matter what (I seem to do this more that older I get) but I am seeing the light from alternate light sources :)
I think a visit to the library and a sober concrete contractor are in order, however most of the guys around me have no experience in the underground home situation and have tried talking me into smaller footers and slab which I can't do because of the loads they have to handle and the soil type which is red clay (which requires a more substantial footing than most soil types surprising enough).
in my experience, every slab that i put poly under has cracked, so i would say if you use the poly just go ahead and do some sawcuts on it to control the cracks. i personnaly just hose down the pour with water just before we lay the concrete that way it will not suck the water out of the mix. then after finnishing i will flood the slab with a hose a few times over a couple days to slow the cure. seems to work for me.
My basement slab is 32 x 58. I poured it monolithically. Since we did not have a pump and the building was already up, the mixer driver could only run his chute in through one window and the basement door. That allowed for about 15% of the slab to be set by the truck, the rest of it (18 yards, if I recall) was wheelbarrowed into place by three guys - me, myself and I. My dad was raking and shoveling into place, and I had a very experienced concrete guy doing the screeding and troweling. We started at noon and ended by shutting off the power trowel at 2 am. A huge benefit was that in the dark shaded basement, the concrete did not dry out quickly, and we ahd a lot more working time.
For a pour that size, unless you can drive a truck all the way around the area, hire a pumper. Even a line pump, and not a truck-mounted pump, will be worth every penny. Two experienced helpers will be able to screed and float at a reasonable speed, and then the final finish could be done by one or two people. If you have little or no concrete experience, hire a pro. It will be worth it.
In my younger days we put foam board over sand and gravel to keep it from sweating ??? Also when working off a non changing print we dug piers down where the loads were to be an thinner else where . We used pipe to level off of an slid them as we pored . To old now to try that much most we ran at once was 50 yards two of us knew what to do and two helpers didn't ::) No way again :D :D
I WON"T EVEN THINK OF A POUR THAT size w/ out a professional crew, $$$$$$$$$$$ Too scary if you mess up. Many things can be fixed, a bad pour cannot.
Ironwood
Quote from: Ironwood on April 04, 2008, 09:37:41 PM
I WON"T EVEN THINK OF A POUR THAT size w/ out a professional crew, $$$$$$$$$$$ Too scary if you mess up. Many things can be fixed, a bad pour cannot.
Ironwood
I don't know...
Seems like dynomite, excavators and dumptsers, followed by more concrete and a professional crew will "fix" a bad pour...
Just my $0.02 worth.
PC-Urban-Sawyer
I fixed a not so good do-it-yourself pour with a grinder over the span of several days including one 32 hour stretch. Dynamite and a do over sounds very reasonable to me :D :D :o
I just got a bid for a 4"x40'x50' slab and labor for the pour and saw cuts at 12' o/c is $2,200. I've done plenty of concrete pours and I'll gladly pay the contractor to do the job while I do something else. I just can't get interested in doing concrete work anymore.
I think a good contractor will save you way more than he will charge you. Just for starters, eight inches is way more thickness than you need all over. With a properly designed slab and a good compacted base, you can probably cut that in half except for the footings.
well I have to have 6 inchs at the floor and 8 on the walls, can't change that. The roof may end up being concrete as well before its all said and done.
going to chat with a contractor this weekend and investigate a couple others to see what I can do on the site to save money.
Quote from: Gary_C on April 03, 2008, 09:23:54 AM
It all depends on how well you are set up and prepared.
How wide of a pour are you planning?
How well are your forms leveled and braced?
How well is your base compacted?
Why eight inches thick?
What strength concrete?
Are you planning a pumper to place the concrete?
Do you have a good cement finisher lined up or will you be happy with water standing on the floor?
If you do not have good answers to these questions, best advice would be to hire a local contractor to advise you and do the pour for you. Concrete is very unforgiving and expensive, especially for 60 or more yards.
polished concrete gympie (https://www.wirthfloor.com.au/)
What's the biggest concrete job you guys have done on your own? Its the one biggest obstacle standing in my way.
Wow, a fifteen year old thread revisited. :D I have worked enough concrete to know I don't want to do it anymore and can't think of any job I would want less then three strong backs. Hand mix, power mixer or truck? Are you wheeling on to a site or hiring a pumper? Ambient temperature also plays a huge role.
I've never been "lead guy" on a concrete pour, and for good reason. But I've crewed on a bunch. If you have two guys that really know what they are doing and two more that have strong backs you can handle quite a bit. I would hire a pro for any thing over 500 square ft. This is not something easily or cheaply fixed so it better be right the first time.
Had to chime in, as I have had trouble with pours in the past, being the second load of the day. The concrete company will have some unused concrete left in the truck and add some to it and bring it out to you. That is "hot mud" and about the time you get it unloaded, it will start to set up. We now have a company that mixes the mud on the job, they have 5 trucks, and haul the gravel, sand, water and cement and mix it in the chute as they unload it. No more hot mud. And they charge for exactly what they unload. Best mud I have ever had on the job. Did a couple concrete jobs this fall, one was a stem wall for a neighbor, then the neighbors helped me replace the slab in front of my garage that had settled. We had 4 guys for the stem wall and 5 guys for the slab, which were tiny compared to what the thread was talking about. Personally, I would divide a slab up into 10 or 12' strips. And always use a plate compactor before pouring concrete.
I have quite a bit of experience in and around concrete. Pouring it, and I ran mixer truck part time for 7 years or so. On a professional flatwork crew, 3-4 guys is plenty. On a weekend pour your own project, with willing backs but not everyone knows what their doing and even the ones that do, don't pour mud on the daily you can figure twice as many. I have had what I thought was too many people show up for pours before, I was wrong and they went home wore out. Have plenty of help, there's no worse feeling than a slab getting away from you.
What are you planning on pouring?
Quote from: wildtmpckjzg on January 21, 2023, 02:57:33 PM
Quote from: Gary_C on April 03, 2008, 09:23:54 AM
It all depends on how well you are set up and prepared.
How wide of a pour are you planning?
How well are your forms leveled and braced?
How well is your base compacted?
Why eight inches thick?
What strength concrete?
Are you planning a pumper to place the concrete?
Do you have a good cement finisher lined up or will you be happy with water standing on the floor?
If you do not have good answers to these questions, best advice would be to hire a local contractor to advise you and do the pour for you. Concrete is very unforgiving and expensive, especially for 60 or more yards.
polished concrete gympie (https://www.wirthfloor.com.au/)
What's the biggest concrete job you guys have done on your own? Its the one biggest obstacle standing in my way.
Just judging by this question, you need more help. Anything over 12' wide, I want someone on the other end of the screed, and someone else to keep all the tools clean. This if the truck can back up to the pour.
I'd wait for the perfect conditions too, but even with the best of those plans, sometimes it goes sideways. I remember one pour when it was supposed to be 64 degrees, but by the time I put the finishing blades on the trowel machine it was close to midnight and snowing. I remember that like it was last night, but it was in 1981 when weather reports weren't as good as they are now, and the bulletproof youth I was then has been replaced by experience since then.
This with people who had done it before with me. Any floor over 12x12, I want two more helpers, and I don't have a good reason to do another one that size by myself.
The one tool a lot of people try to get by without is a roller tamper. Every step needs to be done correctly, or it will work you to death. A roller tamper is probably the best investment you can make.
I found a video that shows one in use:
Concrete Roller Tamper - The Barndominium Show E133 - YouTube (https://www.youtube.com/watch?v=M9Q6r_2qGys)
Notice how many guys he has on that job, and that they keep the tools clean. The edges have to be worked by hand as good as modern tools are.
Fast forward to about 5 minutes in this video. The 10' Bull float saves a lot of headaches too.
Episode 5: Concrete pour | Building a Barndominium Start to finish - YouTube (https://www.youtube.com/watch?v=fxUmqM6c-Bc)
6 good people
4 really good people,,,,,,i have done concrete for 34 yrs