Possibly stupid question about small concrete slab work

[Sebculb]

Hello,

As as a somewhat experienced odd jobber thought I'd offer my stinking opinion: Consider the truck unless the cost is off the charts. much easier. however, If the truck is prohibitively expensive, and you have access to a mixer, don't think twice! I live now in Costa Rica where there's no such thing as a cement truck unless you're the municipality, and huge jobs get done with mixers. For that matter, big jobs get mixed on the ground or in multiple wheelbarrows but that's no fun. But with a mixer and 2-3 helpers you'll be fine.

Does anyone ever mix sand with Portland cement themselves? Pre-mix bags are available here in but exorbitantly expensive, good only for special purpose stuff. If you're working with a mixer maybe you want to order a bunch of sacks of cement and a dump truck of quarry sand with gravel. ...or if you have a tractor just dig it out of the river. But that could lower the cost of the concrete a lot. Truth is I dunno, there was always a truck when I was working up there. But that wasn't rural.

Rebar mesh is easier. Just pull it up into the middle of the slab as you go. I know there's disagreement there but its inexpensive works fine and is fast. There's a reason they sell it.

Good luck!

Sebastian

 

[jenkinsph]

When I mix sacks I break the pallets down to allow me to move them with my forks and 110tlb. That usually means I need to have an additional pallet to take two layers off of each full pallet or remove three layers if the ground is rough. Doing it this way I can easily position the concrete next to the mixer with the sacks high enough for easy transfer to the mixer drum. I break down these pallets ahead of time, preferably a day before. I use the 50lb. (geriactic size) sacks which work out to be slightly less costly in my locale.

I use sacks for small pours or places I can not get a ready mix truck to. Sacks are more expensive than ready mix if you need more than two yards. With a truck you can use the chute to spread the concrete and fill these small forms quickly. That can be important as you will have more time to work the slabs without being tuckered out with all the mixing.

While I may form large jobs and get them ready I will always call in a good concrete finisher to handle the actual pour.

 

[RNeumann]

Oh wow! I'm sorry that I have neglected so many helpful posts. I have been away from a computer all day and honestly didn't expect to receive so many replies! Thanks to everyone who shared some thoughts.

To answer a few questions: I live in Northwest Florida, but I planned on doing the work this winter, so it would possibly be more doable(?) due to temperature, etc. I planned on leveling grade and preparing the site(s) myself, tamping ground, and laying some gravel substrate for all slabs, and I would probably want to try to do rebar as well for durability. The "workforce" would be my wife and myself, both 37, and the time frame would be over weekends. The main reason why I am thinking about trying to do this myself is that I live "in the country", about 45 miles from a reasonable sized city, and EVERYTHING that I have priced to have done has been double what I would pay if I lived in town, because almost all service providers are located in town and don't want to drive out, or if they are willing to do so will have weeks of delays to make it out.

I had planned on doing 4" slabs, with one 12'x12', one 20'x10', and one 24'x12'. For the larger slabs I would do sections, say two 10'x10's or two 12'x12's with an expansion joint. After reading some of these replies, though, I just don't know if it is something that I would be willing to try to tackle. At least maybe not the larger slabs, anyway. Someone did bring up a good point about the high cost of personal labor, so I will have to re-evaluate I suppose!

You may be thinking about this differently than you need to. You can form and pour your slabs in smaller pieces. If it’s a 10x10 slab you can do 4-5x5 pours. Just notch the forms so the rebar extends to the next pour. This is common on bigger projects. Just put a little rounded edge on each pour and when you are done it will look like control joints. What you will have is called a “cold joint”. And if you are concerned about weeds or dirt in the cold joint they make a caulking specifically for cold joints.
One pour a week, or even one a month, and your place will be ready for summer!

 

[Stimw]

I have done 12' X 24' slabs, supervised 40' X 65' slabs. I have even driven the ready-mix trucks!
U-tube is your friend, just google and watch until you understand the process.
For you slabs the truck is your easiest route. Get friends or relatives to help. Just know, you will probably never work harder.
I never made laminate kitchen counter tops before. I watched a bunch of videos and put in 3 in my kitchen, 92 sq ft total. They turned out perfect!

 

[GLyford]

I have done the counted shovels method using sand, stone and portland, and a measured jug of water. It adds to the time, dealing with bags is faster but making your own mix as you go is certainly do-able. I was using a HF mixer, and filling one of those "patio block" molds. The only problems I have had with the patio have nothing to do with the concrete...slope, drainage, roots, wrong fill between blocks allowing weeds, but not the concrete.

Growing up, we did a couple of projects where we measured out the sand and stone using a 1' square (inside) plywood box. In one instance, we mixed on a concrete driveway, another time we used an 8x8' mixing platform made from 2 sheets of plywood and 2x4's. Mixing was done with hoes and square point shovels. With 3 people it went OK. Made concrete a number of times from bagged mix mixing it up in a wheelbarrow. I set a bunch of fence posts recently, and it was easier to just mix in the wheelbarrow than it was to get out the HF mixer.

But for stuff like a 5x10 slab, or landings for deck stairs the mixer was a big help. The more bodies you can throw at the problem the better, the landings were about as big as I would go now without another body. I have done a couple of 10x12 slabs and a half dozen sonotubes with "bigfoot" footers with either a regular truck, or for the tubes, a mix-as-you-go truck. Cost was about the same either way, for the regular truck paid extra for a minimum pour and for weekend delivery.

Relative to the cost of the rest of the project the extra fees were a drop in the bucket. Any regret I had over paying extra pretty much evaporated as soon as I finished writing the check.

My take is for the size of the slabs you are talking about, if you have a truck come and have to pay extra for distance/weekend, etc., it is still worth it. A truck is only half the work, there will still be plenty for you to do to place the concrete, screed, and finish it, and you will still be dead tired at the end of the day.

 

[EddieWalker]

Sacks cost more money then shoveling your own mix, but it's faster and easier. When working alone, speed is everything.

 

[geteh]

I just read a couple posts about portable cement/concrete mixers in the "Build It Yourself" section, and they got me thinking.

I currently have a need to do at least one 4" concrete slab, and maybe up to three different slabs for various projects around the house, ranging from 144 sq. ft. to 300 sq. ft., but I have delayed them because of the cost associated with having someone come out to pour my slabs. Of course I would rather Do It Myself! But every time I look into the Quikrete calculator (or similar tool), it shows a range of 81 and 169 80-pound bags required to do these sizes of slabs. That seems pretty ridiculous to me to even attempt to do with a small mixer from Lowe's (4 cu.ft.), or even the PTO mounted mixers from Agri Supply (8 cu. ft.).

I am by no means a builder, and have never poured anything other than a few 2'x2' slab/piers, especially nothing that may require rebar/reinforcing etc. Are these jobs doable as a DIY'er with a basic mixer and hand tools for concrete quantity takeoff, or am I going to bite WAY more than I can chew to attempt to save some money? They don't have to be anything impressive at all, just basically a hard surface(s) to put stuff on, including my 40hp Kioti and some implements.

If anyone has any tips, books, websites, or videos to point me towards, that would be awesome, too!

Any help is appreciated!

Hello. I've purchased a 30x40 mueller building and and trying to get a slab done. I had someone lined up to do the slab and it fell through. I contacted a few others and they either would not call me back, or just high bid it. It seems that everyone is doing commercial work and no one really wants to mess with a small shop. Anyway I have decided to try to do this myself.
I'm on red clay and have fairly uneven ground. My brother in law did me a favor and did my dirt work and built me up a pad.
There's seems to be differing opinions and i curious to see what sort of response i get but some folks say to use sand under the slab. Others say crushed stone. Some say the sand cannot take enough load. Others say it doesn't matter. Just curious what some on here think.

 

[CalG]

I've done the sand/stone/cement by the shovel into an old Sears mixer.

I've done the 40+ bags of sakrete.

Just last month I had done a 24' X 24' slab under a pole building (car park) Those youngsters make it look easy, I'm getting on in age ;-)

But I have a few more pads to go on my own . There is nothing says you can't place 30 square feet at a time!
6X5X 4 " is around 20 bags.

And about the optimal size for joints in my opinion.

I've done some like that (NO STEEL) and have been very satisfied with the results. (apron in front of the shop/garage.

Vermont weather, lots of freeze thaw.
1x 4 boards and a bunch of metal pins (rebar) string line and a level are all the form work needed. a 2X to screed it off, and a wooden float to give a non-slip surface.

OH! Don't forget the tamper! ;-)

 

[ultrarunner]

I’ve done 1 yard from sacks alone and 2 yards with a helper…

It was kind of remote so best option.

Having the sacks on a small flat bed so no real lifting as sacks at waist high already which helped a lot.

Water in 55 gallon drum with a pail to measure.

I did 2.5 yards with the 1 yard concrete gondola alone

It was not planned that way but help flaked.

I was able to back the gondola exactly where needed so very little wheel barrow work for the garage floor and out of the sun.

Don’t think my hands would be up to it anymore.

 

[Egon]

Hello. I've purchased a 30x40 mueller building and and trying to get a slab done. I had someone lined up to do the slab and it fell through. I contacted a few others and they either would not call me back, or just high bid it. It seems that everyone is doing commercial work and no one really wants to mess with a small shop. Anyway I have decided to try to do this myself.
I'm on red clay and have fairly uneven ground. My brother in law did me a favor and did my dirt work and built me up a pad.
There's seems to be differing opinions and i curious to see what sort of response i get but some folks say to use sand under the slab. Others say crushed stone. Some say the sand cannot take enough load. Others say it doesn't matter. Just curious what some on here think.

A well packed drained foundation is all that is required. The materials matter not.