Tech / Special Interest → Home Improvement > [Masonry] Pouring concrete steps

[Masonry] Re: Pouring concrete steps

That's an interesting idea.

Wouldn't that kind of heat/cooling wreak havoc on the concrete though?

I certainly don't want to discourage you from tackling this yourself, but is there a chance that you could hire someone with experience to 'help'. You could have them check your set up (you definitely need more fill in there - Unxchay pointed this out already), help/direct with the pour and do the stripping and finishing. Essentially, you could do a lot of the grunt work and act as his/her 'helper'. You'd also have the opportunity to take some videos or pictures so we can ridicule you admire your work.
You'd hate it if there were problems. Concrete is kind of permanent
--

Confidence is good. It's not rocket science. I just know how the stuff can get away from you.
Having someone helping that has worked with it before will be invaluable.
--

Is a corner trowel necessary for the inside corners of the steps?

It seems not a lot of stores carry them. Is it worth finding?

Sharp inside corners are an invitation to cracking. A corner trowel puts a radius in that space, thereby minimizing the tendency for cracks to form.

Good to know. Thank you!

This isn't happening tomorrow. Still haven't got the rebar in, and it's supposed to rain all day tomorrow.

At least I bought all the tools I need, the rest of the concrete, and the air entrainment and fibers.

Hopefully next weekend.

While it's raining, I've been planning. Here's my step by step. Anyone find anything wrong with it?

Mix:
•2 bags of concrete
•5 qt water recommended by manufacturer. Start with 3 (since admixture decreases the need for water).
•Measure slump with plastic cup and add water as needed.
•Note actual amount of water used for next batches.
•16.5g of fiber
•454g (full bag) of admixture

Pour:
•Spray forms with cooking spray (as form release)
•Brush concrete adhesive on foundation immediately before pouring
•Pour one step at a time, from bottom step up
•Stab with rebar or shovel to remove air
•Screed with trowel
•Repeat for each step
•Vibrate entire form with palm sander (don't overdo it)

Step finishing:
•Wait for surface puddles and sheen to go away
•Float
•Edge
•Remove riser form by pulling straight up
•Fix corners with corner trowel
•Float riser
•Edge
•Broom

Side finishing:
•When nail cannot be pushed in by hand (8-10 hours), remove remaining forms
•Trowel side, using added sand/cement mix if needed

•Keep moist for 5 days by misting with garden hose when needed

To minimize the amount of concrete I need, I was thinking of making an enclosure of sorts with chicken wire, so I can add more gravel without it falling next to the side of the form.

One thing I think is still unanswered, is when should I remove the form from the bottom steps? Can that be removed when I remove the other riser forms? Or should I wait until it's time to remove the side form?

Maybe it's just me, but I wouldn't use pre-mix on something like that. I'd do it the old fashioned way and use a Portland, sand & gravel mix and make it on the strong side. I'd at least use an extra scoop or 2 of Portland in each mixer full. How many sacks do you figure on using $$$$.

Based on the specs of that bag mix, it'll cure to 5000 PSI after 28 days. After the admixture and fibers, and careful water measurement to ensure low slump, it'll likely be stronger. I don't see what mixing it myself would add, other than saving a bit of money, though I haven't priced that out.

It'll be about half a yard. Half a yard works out to 27 bags. At $4.09 a bag, that's $110.43 for the pre-mix.

I revised the amount of the admixture I'm going to use. My previous calculation (84g) was based on the store's recommendation (given to my father-in-law, since he picked it up for me) of one full bag (454g/1lb) for each full bag of portland cement, where (he said) 5 bags would make about one cubic yard. Since I'm using premixed, I had to do some math.

But there were no directions for usage on the bag itself. So I had emailed the company on Friday to confirm the directions, telling them I'd be using premixed concrete and mixing two bags at a time. They replied yesterday morning saying to use a full, 1lb bag in my mix of two bags of concrete. I found that surprising. I questioned it a bit, but she said she confirmed with her supervisor, and it's correct. I asked why I need 4-5 times as much of this stuff as their other products (which are only sold in bulk) and she said that the other products are more concentrated, and this one is simplified to eliminate measuring. It's made so you can throw in a whole bag at a time.

So I called the store myself and talked to the guy my father-in-law got the recommendation from. He said he knows what the manufacturer's recommendation is. But in his experience, he's found it works just as well with less. Based on what I'm doing (two bags at a time), he'd recommend half a bag in the batch - half as much as the manufacturer recommends. So I'll go with that.

The first batch will be the test. I'll measure slump before adding any of the additives, then throw the additives in and see how soft it gets. My only concern of using too much of the admixture is it getting too sloppy from the plasticizer and flowing over the forms of the bottom step when I do the upper steps. Though I'm not sure if that's a valid concern. And even then, it would just mean I have to wait a bit in between pouring steps.

That's a fair question, though this guy doesn't just stock shelves. It's a building supply company that sells to contractors as well as the general public. He's a salesman who works with contractors. He seemed to have more experience than just some dude stocking shelves. And being a salesman, it would be in his best interest to sell me more of the stuff, but he suggested half as much.

By the manufacturer's own admission, this product is dumbed down so that the whole bag can be used at a time. And this isn't an exact science. It doesn't mean the whole bag must be used at a time.

Plus, the cost. The manufacturer is saying one bag per cubic foot. At $5.50/bag times about 14 cubic feet, that's steep.

Considering (1) the fact that this isn't even required in the mix, (2) the recommendation from someone who works with contractors every day, and (3) the cost, I'm comfortable settling for using less.

So you are going to ignore the manufacturer and and listen to someone selling in a building supply company?

Yes. Like I said, this isn't an exact science. Using none of it will not make my project magically fall apart, so using some of it will be better than nothing.

This admixture has several properties: "superplastisizers, air entrainment and water reducers". All I wanted is the air entrainment, but I can't get that alone without buying gallons of it (though I may still try). I don't particularly care about increasing the workability of the concrete, though that is a benefit.

Though..... I guess the air entrainment is the only property of this that's permanent and thus is most important to mix right.

And I have wasted $40 on stupider things.

0 bags, no grief.
1 bag gets you grief.
2 bags gets no grief.

I think your compromise seems reasonable myself.

Why not just order the proper concrete pre-mixed and ready to pour? Do you not have enough for the minimum order?

Two reasons. The biggest is that I already had 13 bags of the concrete left over from when I dug up my basement last summer for the bathroom there (that's another project I still need to finish). That's about half the concrete I need for this project.

The other is cost. Most places have a minimum price, not so much a minimum order. One place was $380. Though there is one place about a half hour away from me that rents out those small trailers of concrete that you can pick up with your own truck. Their price was $135 (tax included) for a half yard. Plus two hours of driving with a friend's truck (there and back twice) and topping up his gas. Or I can pay the extra $45 for delivery (though they didn't quote me out of city delivery, which might be more), which would probably work out to about the same as topping up my friend's truck. So that's at least $180. Plus the hassle of having to get the trailer back within 2 hours as they require.

Using the bagged concrete, I'm looking at $110.43 for the bags, plus $77 for the admixture (I decided to go with the manufacturer's recommendation), plus $6.95 for the fibers, which comes to $194.38. That doesn't include the lumber used for the form of course.

But considering I would probably have paid a couple thousand for a contractor to do it, I can't complain.

Around here, there's a three yard minimum for delivery of concrete. Why pay that premium if it's more than twice what the OP needs. As long as he's willing and able to do the "grunt" work of all that mixing, why not do it his way?
--
Keep your eye on the ball, your shoulder to the wheel, your nose to the grindstone, and your ear to the ground. Now, try to work in that position!!!