Pouring Small Concrete Pad In Batches?

[DC73]

I need to pour a fairly small concrete pad. It should take about 10 of the 80 lb bags of concrete.

From past experience, it'll be difficult to mix more than 2 bags at a time in my wheelbarrow. I can rent an electric 4 bag mixer from Home Depot that I can put on the back patio which is the best place to set up the operation. I can rent a trailer mounted gas engine mixer from Home Depot that will do all 10 bags at once. But it won't fit in the backyard, so multiple trips with a wheelbarrow.

If I go with 2 or 4 bags at a time, I'm concerned about the first batch setting up before I finish the subsequent batches. Valid concern?

Recommendations?

Thanks much,

DC

 

[spudley]

Poured 10 bags a while back in a two wheelbarrows with another guy. Plenty of time to work it. Just don't stop for lunch

 

[AndyCBR]

In the heat of Summer that may be an issue but if you do it now I don't see a problem. I would mix 2 bags at a time just so it i easier to mix.

Just screed it as you go starting from one side or corner. IE fill the form to the top and then work your way toward the other side.

 

[naturalgas]

I did 12 bags in September about 75degree day, two at a time with a cheap harbor freight mixer I bought used. It went well with no rushing to get it mixed.


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[bczygan]

I need to pour a fairly small concrete pad. It should take about 10 of the 80 lb bags of concrete.

From past experience, it'll be difficult to mix more than 2 bags at a time in my wheelbarrow. I can rent an electric 4 bag mixer from Home Depot that I can put on the back patio which is the best place to set up the operation. I can rent a trailer mounted gas engine mixer from Home Depot that will do all 10 bags at once. But it won't fit in the backyard, so multiple trips with a wheelbarrow.

If I go with 2 or 4 bags at a time, I'm concerned about the first batch setting up before I finish the subsequent batches. Valid concern?

Recommendations?

Thanks much,

DC

The 4 bag mixer is your answer, even if you only mix 3 at a time. It will go very quickly for one person.

I regularly have mixed enough in a wheelbarrow, to do a 3'x3'x4" thick pad.

Yours is just over 4'x4'. With a helper you could hand mix it.

Bill

 

[stage20]

is your work area accessable for a concrete truck? call around to a few plants. if its not out of the way, they will drop off a small amount for a flat fee whether it be a fresh mix or left over from another job.

the price may out weigh the cost of manual labor or renting a mixer. dont forget the time and effort to pick it up and return it. its all time and money

 

[Keel]

Wear a mask while mixing..
If you can rent a 10 bagger. do it..
I have a metal 4 bagger , and the lift, mix, bucket or wheel barrel and then do it again,, takes time and is a work out..
If you do it with a smaller mixer.. get a buddy.. one mixing as the other is dumping..
I've done it alone, to make a 4'x4' 6" slab for the compressor, and to redo the hollow front house steps.. ( blew a hole in them air gunning the brick mortar off the top.. oops)
it wasn't bad, doing the pad, as I had the mixer lip right over the pad form.. it was mix and dump ,mix and dump..

The pouring a 8'x8' floor under the breezeway for storage.. was a work out.. but that was allot of bags of mix..

 

[captain14]

Doable , but check CL. My local CL seems to have small mixers on it

I'm sure people buy it for the job and sell it afterwards. You may get lucky and be able to resell for your buying price.

 

[nine4gmc]

We did 11 bags in our driveway repair last year by simply dumping the dry bags in until it was slightly over full and wetting it with the hose on shower mode. We have been driving on it for almost a year now with no problems. ymmv

 

[DC73]

The 4 bag mixer is your answer, even if you only mix 3 at a time. It will go very quickly for one person.

Thanks guys. I'm leaning this way. I can't get either of the mixers right up to the final pouring location but using the 4 bag mixer will allow me to get it fairly close resulting in shorter trips with the wheelbarrow. Sounds like I can do this by myself which helps.

We did 11 bags in our driveway repair last year by simply dumping the dry bags in until it was slightly over full and wetting it with the hose on shower mode.

This approach is why I'm having to re-pour this slab in the first place. Without proper mixing the existing slab was crumbling so bad that it was easily broken up with a shovel and a small hammer. It took me longer to haul the debris away than it did to break it up. I hope your driveway holds up.

DC

 

[thammel]

Agree with wear a dustmask while mixing. I've done 8-10 bag pours (HVAC pads) many times using the wheelbarrow to mix 2 bags at a time. I've never had a problem with concrete curing too quickly...of course, I didn't take breaks for lunch or anything! Don't worry. It will be fine.

Tom

 

[joes169]

I once mixed 114 bags in one day with an electric 3-4 bag mixer, but I only mixed and had 2 of my employees hauling the concrete into the house and screeding/finishing it. I'm sure the Quikcrete is different by region (it's blended and bagged at regional Spec-Mix plants across the country) but the standard stuff here is really slow setting, so I doubt you'll have a hard time keeping up.

 

[mm08822]

I need to pour a fairly small concrete pad. It should take about 10 of the 80 lb bags of concrete.

From past experience, it'll be difficult to mix more than 2 bags at a time in my wheelbarrow. I can rent an electric 4 bag mixer from Home Depot that I can put on the back patio which is the best place to set up the operation. I can rent a trailer mounted gas engine mixer from Home Depot that will do all 10 bags at once. But it won't fit in the backyard, so multiple trips with a wheelbarrow.

If I go with 2 or 4 bags at a time, I'm concerned about the first batch setting up before I finish the subsequent batches. Valid concern?

Recommendations?

Thanks much,

DC

I do this same thing many times over for generator concrete pads - 3' x 5' x 6".
I mix 2 bags at at time in wheelbarrow with mortar hoe as I can mix and pour faster than 3 bags at a time. Just get all set up to do just that work before you start. Everything is there within reach.

Spread it out across the area more or less, but never reaching the top of the forms. Keep going like this until you're done. Compact each pour onto the last pour with garden rake/asphalt rake. Make sure edges/corners are really consolidated.
Use 6-6-10-10 mesh.

Before you screed the top, compact it, do a rough screed, let settle, and once water starts to evaporate enough, final screen, cut forms from edges with trowel and start rough corner edging. Float with wooden and steel trowels once water is gone.

Only real time to worry is in the direct sunlight and summer, or late into night - freezing temps and also surface water takes forever to evaporate at night. If sunny, just cover concrete with tarp, plywood etc. while mixing.

Make sure it doesn't freeze for 3 days.

 

[DC73]

. . . also surface water takes forever to evaporate at night. If sunny, just cover concrete with tarp, plywood etc. while mixing.

Make sure it doesn't freeze for 3 days.

Thank you for your detailed instructions. Good refresher. To clarify, this will be an indoor pour so around 70 degrees.

Your surface water statement got my attention. If I have excess surface water, should I sponge it off or just let it be? I can adjust the temperature to higher if that would help.

DC

 

[ddurrett896]

Buy this and a couple 5 gallon buckets. Love mine!

http://www.contractorsdirect.com/Bucket-Mortar-Mixer

 

[mm08822]

Thank you for your detailed instructions. Good refresher. To clarify, this will be an indoor pour so around 70 degrees.

Your surface water statement got my attention. If I have excess surface water, should I sponge it off or just let it be? I can adjust the temperature to higher if that would help.

DC

Indoor pour is so much easier - time of day, temp, rain - all controlled to your advantage.

Surface water is first handled by making sure your mix is not too wet - limited slump. If you start seeing water while compacting, try a little less water in next batch - you can only back off so much before you can't mix it fully/uniformly though. Be conservative from the beginning.

As you screed off across top of forms, you can get rid of more if it exists. Eventually you just have to wait for enough evaporation. Maybe all little extra heat (5 degrees) and a fan would accelerate slightly faster evaporation.

Since you have a small slab, let water evaporate until almost like cake icing - still plastic but not slush. Don't rush troweling. If you raise to much water back to the surface, you have to wait again for it to evaporate and it slightly weakens the top surface.

Since you are doing this inside, it is all in your favor. all you need is time and a little patience.

 

[Fatboy148]

With concrete you get one shot at the title.

Do you know anyone that has worked concrete before? It might be worth it to have some experienced help.

 

[DC73]

Buy this and a couple 5 gallon buckets. Love mine!

http://www.contractorsdirect.com/Bucket-Mortar-Mixer

I've discovered that I can get the HD 4 bag mixer directly to the pour site (they gave me wrong dimensions when I called the first time) so that will be much easier than 1 bag/bucket at a time. But, this tool intrigues me because a future project will involve mixing and pouring several bags of self-leveling compound. How many 55 lb bags of SLC will fit in a 5 gallon bucket AND not be too much for this tool?

Since you are doing this inside, it is all in your favor. all you need is time and a little patience.

Thank you again for your help. I've poured concrete a few times over the years but never indoors and never in multiple batches. Your info helps a lot.


DC

 

[DC73]

Got it done. Went pretty well. The biggest hitch was the rental mixer from HD had been severely abused. One wheel was very wobbly which made steering an issue and the drum was so out of round that it slung water and a bit of concrete out when mixing 4 bags at a time.

Thanks again for all the help.

DC

 

[ddurrett896]

How many 55 lb bags of SLC will fit in a 5 gallon bucket AND not be too much for this tool?

Honestly have no clue. I did my 50 sqft shower pan by myself using fat mud and had no problems.

 

[mm08822]

FWIW, a 94# bag of portland cement (1 cf) requires two 5 gallon buckets when dry.

A bag of hydrated lime ~40# is ~1+ cf.

Maybe check coverage listed on bag for wet volume.