How big of a slab could I do by myself?

[scootr]

12x17 I would quarter it.

 

[quicksandfarmer]

12x17 I would quarter it.

I assume you mean four 6x8.5, but part of me thinks that it would be easier to do long narrow strips, 3x17. Screeding is much easier with a narrow strip.

Question two: should I do cold joints, tie them with rebar, have expansion joints?

 

[scootr]

I assume you mean four 6x8.5, but part of me thinks that it would be easier to do long narrow strips, 3x17. Screeding is much easier with a narrow strip.

Question two: should I do cold joints, tie them with rebar, have expansion joints?

Cold joints, no expansion. Definitely use reinforcement in the form of rear or wire. Make sure you finish the joint edge nice. When you go to pour up against it lay down a sheet of 10mm plastic so you pour over the plastic and it covers yesterdays pour to keep things nice. Then just cut the plastic off when you are done.

 

[paulsharvey]

So the slab is 12x17, the door is in the 12' end. So would you recommend three pours of 4x17 or three pours of 12x 5'+?

If it doesn't matter, it seems to me the 4x17 would be easier, I can roll the mixer between them the whole way. Do the two sides and let them harden and then roll the mixer in on one of the sides to do the middle. It also would mean I never have to drive over the joints.

Hmm, I think I would avoid having 3 joints in the doorway, so I guess given the choice, I would go 12x5, 12x7, 12x5. Knowing the middle section will be the easiest, because you are working off two fixed points, and working the middle. I just think it would look like a turd if you have 3 narrow pours, and the exposed joints all at the 12 ft door.

I would say for a redimix truck, a single guy can pour and finish about 5-6 CY. It's real work, and he better have good weather, and be prepared. Anything over 6, you really need a 2nd guy. 2 guys can readily do 20 per day, but depending in the pour, their work ethic, ease of work, and finish, 30 cy isn't out of question. Then everything over 20 yards, you figure add another guy.

Pallet and Mix, 1 guy can do 1 CY per day, either in a wheel barrow or with one of those small 2 bag mixers; probably upto 2.5 CY with a dedicated, real concrete mixer, or a "mudmixer". In both cases, your going to Know you worked that evening, and the next day, and so on...

How thick do you want to go? 4", 5", 6"? I know the "smart" folks claim WWF doesn't do anything but prevent curing cracks, but if you go 4", I'd throw some wire in it. If your doing 5"/6", I might skip it.

I Would put all your plastic down for the 12x17 pour, your side forms, and bulk head forms. Where you will get real debate, is do you want an expansion joint material Or dowel and tie all 3 slabs together. Sidewalks you dont dowel, and you specifically have cuts and expansion to keep them separate, but structural additions, you typically have a method, such as dowels, keyway, ect to tie the additional slab to the old slab.

 

[quicksandfarmer]

Thanks. A thickness of 4" is 2.5 CY, 5" is 3.1, 6" is 3.8. I think I'd rather use rebar than mix and pour another 1.3 CY.

A 12x7 section 4" thick is 1.04 CY, so almost exactly a yard, a good day's work.

My local rental house wants $50/day for a small mixer and $115/day for the big (9 cu ft) one. Since I'd have to rent for three days it seems worth buying a small mixer from Home Depot, Harbor Freight or Amazon.

The Quikcrete Concrete Calculator says 152 60lb bags for 2.5 CY.

 

[Runner]

I assume you mean four 6x8.5, but part of me thinks that it would be easier to do long narrow strips, 3x17. Screeding is much easier with a narrow strip.

Question two: should I do cold joints, tie them with rebar, have expansion joints?

I would do 3, 5+ x 12. I did cold joints (construction joints) tied with rebar (not expansion joints). Has held up beautifully.

 

[paulsharvey]

Thanks. A thickness of 4" is 2.5 CY, 5" is 3.1, 6" is 3.8. I think I'd rather use rebar than mix and pour another 1.3 CY.

A 12x7 section 4" thick is 1.04 CY, so almost exactly a yard, a good day's work.

My local rental house wants $50/day for a small mixer and $115/day for the big (9 cu ft) one. Since I'd have to rent for three days it seems worth buying a small mixer from Home Depot, Harbor Freight or Amazon.

The Quikcrete Concrete Calculator says 152 60lb bags for 2.5 CY.

Home Depot does a discount on single full pallets, but Lowes, last I bought, you had to buy 2 full pallets to get the bulk discount. Never asked about delivery fees, but with a Moffet/Piggy Back forklift, they can deliver the pallets to right where you need.

 

[paulsharvey]

I would do 3, 5+ x 12. I did cold joints (construction joints) tied with rebar (not expansion joints). Has held up beautifully.
View attachment 1906273

Mine, I did wire continues through the whole floor, and only used a edger at the edges, so the WWF held the separate slabs together. Your bulk head form, you can rip down a 2x4, and only have it say, 2.5" "tall" and run the wire free through it to the next section. If appearances matter, you can always use a polybutylene caulk on the joint later, after maybe 28 days.

What are your walls? If block, I would out expansion against them. If post and beam, I would put expansion around the posts.

 

[ning]

If you are under 40, a BFI under 20%, a strong back and a healthy set of lungs, you stand a good chance of success doing by your self. ​

The higher the numbers, the more help and work time you need.

ok I'll bite
what's BFI?

 

[jyoutz]

About a decade ago I needed concrete for an area that would be hard to get a full size truck mixer into. I found a a place that rented “you tow it” concrete. Basically a trailer mounted mixer that held 2 cubic yards of concrete. They load the dry mix and you add the water at home and turn on the mixer. Those units can be truck towed and get into as tight a spot as you can back it into. Break up your slab into 2 yard sections.

But, also in most places there are small concrete contractors who will do small jobs. Maybe search a bit more.

 

[paulsharvey]

About a decade ago I needed concrete for an area that would be hard to get a full size truck mixer into. I found a a place that rented “you tow it” concrete. Basically a trailer mounted mixer that held 2 cubic yards of concrete. They load the dry mix and you add the water at home and turn on the mixer. Those units can be truck towed and get into as tight a spot as you can back it into. Break up your slab into 2 yard sections.

But, also in most places there are small concrete contractors who will do small jobs. Maybe search a bit more.

There is one local guy that will deliver in this set up, and about 1h away there is a rental company you can do it yourself. Only thing difference, it's redimix, and you don't add water. The catch with the rental place, the 1 cy of concrete includes 1 hour of rental; but the issue, it's 1 h away, you need to pour, clean up, and then... what take it back and hope 2 hours it hasn't gone too far to finish. I would want to at very least float and edge. After 2 hours, on a cool day, sure you can still work a cream back up, and broom, but on a hot day...

 

[jyoutz]

There is one local guy that will deliver in this set up, and about 1h away there is a rental company you can do it yourself. Only thing difference, it's redimix, and you don't add water. The catch with the rental place, the 1 cy of concrete includes 1 hour of rental; but the issue, it's 1 h away, you need to pour, clean up, and then... what take it back and hope 2 hours it hasn't gone too far to finish. I would want to at very least float and edge. After 2 hours, on a cool day, sure you can still work a cream back up, and broom, but on a hot day...

Sounds like you need a helper to drive the trailer back after your pour while you work on finishing the concrete.

 

[newbury]

How much "r etard" can you put in and have it still bond like it needs to?
I see they now have machines that will build walls by putting down layers like squeezing toothpaste from a tube.
Can one pour say 2 foot wide sections next to each other and have them bond?
(note-I tried to write the word I had read used for slowing down the curing, but it all turned into astericks)

 

[paulsharvey]

How much "r etard" can you put in and have it still bond like it needs to?
I see they now have machines that will build walls by putting down layers like squeezing toothpaste from a tube.
Can one pour say 2 foot wide sections next to each other and have them bond?
(note-I tried to write the word I had read used for slowing down the curing, but it all turned into astericks)

If you look at the old cast in place concrete buildings, they absolutely would pour a 24" layer, and raise the forms. Take a look at the "Lightner Muesem" in St Augustine, and you can clearly see the individual layers. It looks like it was originally built in 1887. I assume they either A added vertical wet set dowels between each pour, or B, it just has a cold joint, and the layers are wide enough that gravity does the rest?

For the 3d printed ones, not really sure how they are dealing with cold joints, or if the concrete is really just the shell, and thermal mass, and the "structure" is steel?

I dont actually know how much you can ****** concrete, but you can add bonding agents to help adher them together, as well as dowels, and epoxies. We did a mast arm foundation repair with a 6000 psi epoxy...

 

[newbury]

I would do 3, 5+ x 12. I did cold joints (construction joints) tied with rebar (not expansion joints). Has held up beautifully.
View attachment 1906273

Are those pads in the picture 5'x12'?
Looks good.

 

[Runner]

Are those pads in the picture 5'x12'?
Looks good.

They are 6 x 12.

 

[bigtiller]

ok I'll bite
what's BFI?

Body Fat Index

It describes the percentage of total fat in the body by measuring weight and height.

It is a little more accurate than a BMI measurement.

 

[garry1p]

I poured a slab using 60 lb bags pretty much like runner, I did buy a mixer from Harbor Freight only problem was if you did not keep grease on the gear it would lock up. Not a big deal just something you had to be aware of.
Kind of a pain to clean at the end of the day since I was pretty much worn out. It took me several weeks working on weekends.
I also laid down a sheet of 4X8 plywood making it easier to move the mixer around.
I don't remember how many bags but I was working alone outside so the weather had to be considered
I also made it less than perfectly smooth.
Only thing I could recommend, no matter how you do it, pace yourself and know your limitations once you start a section you have to finish it.

 

[MossRoad]

How much "r etard" can you put in and have it still bond like it needs to?
I see they now have machines that will build walls by putting down layers like squeezing toothpaste from a tube.
Can one pour say 2 foot wide sections next to each other and have them bond?
(note-I tried to write the word I had read used for slowing down the curing, but it all turned into astericks)

retarder

 

[EddieWalker]

I personally will only use rebar in a concrete pad. It will be set on chairs so it's in the middle of the pad. Wire is impossible to walk on and keep in the middle of the pad. The most common lie told with concrete is that they will pull it up while spreading it.

I have my rebar done before I pour my first pad. The form that divides that pads has notches in it so it fits over the rebar. When the concrete is dry, the form comes off, and then goes to the edge of the next pad.

Pouring one pad in a day wears me out, so I do them once a week. During the week, I buy another pallet of concrete, move my forms, clean up the area and stage everything for the next pour on Saturday morning. I'm in no rush to finish, and the more time I take to get everything in place, the easier it goes.