Gonna pour my own sidewalk *goulp*

So, remember the other day I posted about the sidewalk? Well my intensions were to get it poured when the footer for my foundation gets poured. My contractor bailed on me and I've not been able to find anyone else to do the small job for less than quite a few grand. (I guess there is the cost of it being too small of a job buried in there.) Changed my addition to post a pier. *sigh* It's cheaper though....

So, I'm gonna do it myself. I'm looking at 63sqft. I've estimated that I'll need about .8 to .9 cuyd of concrete. I've found a lot of how to online, but I've not found a lot of info on estimating my materials. I've heard from numerous sources not to buy readymix concrete, so that's out. I'll mix it myself.

I'll probably buy standard Quikrete Portland Cement in the largest bag I can find. As well as the cheapest sand and gravel I can find in bags. Pea sized river rock? Crushed rock? Larger stuff? What size?

Cement:Rock:Sand volumetric ratio of 1:2:3 ok?

I don't really want to pay a delivery charge for materials and have no place close by to get a load of sand and gravel dumped.

Thanks!

Jason

Concrete weighs about 150 #/cubic ft.

You will want at least 5 bags of portland cement (94#each) that was about $9.50/bag at HD yesterday. The usual rate from my memory is 5.5 sacks per cubic yard. Go light on the water

You might be a good candidate for a product that is called cart-crete in some areas. You get a cart of pre-mixed concrete. I don't know if they deliver or if you have to haul the cart. One yard weighs about 4000 pounds.

If you do it yourself you will have to do a lot of shoveling, and you will have to rent a mixer or spend a lot of time with a hoe.

I have found that the Sack-crete is often coarse and with very little cement. Maybe good for putting a post in the ground but not for a sidewalk. If you get Sack-crete, get the best quality.

If you mix your own, you should use about 5 gallons of water per full bag of cement. You might use an extra half gallon if your aggregate is very dry. More water makes poor concrete.
http://www.concretenetwork.com/concrete/slabs/ratio.htm

Cart-Crete Example Link

http://www.buncerental.com/ucart.htm

Here is a link to someone in Washington that sells cart concrete.

Thanks, Bob. I didnt find any cart concrete here in Columbus, but it's novel idea. Knowing my luck, there would be a traffic jam and I'd end up with a two ton paperweight. Heh

So basically we're looking at around 516LBs cement per per cubic yard of concrete. What about the sand and gravel?

I'd need 5 bags of cement, 465LBS for my project. And at a 1:2:3 ratio, that'd be 6 parts: .15 cuyd cement (465LBS), .3cu yd stone and .45cu yd sand. Last I saw, sand and stone were sold by the weight, not volume. How do I estimate that?

Thx
Jason

The usual ratio is given as cement:sand:gravel.

The small sand fills the spaces in the stone and the cement fills the spaces in and around the sand. That is why the density of concrete is about 150 #/cu ft while the aggregate density is about 105 #/cu ft.

The ratios of cement:sand:gravel assume that the gravel is "well graded", which means a continuum of sizes. Much of the stone that you get these days is much more uniform. The solution is to get more sand.

You don't want to run out while mixing. I suggest about 1800 pounds each of sand and stone. If you can get well graded gravel, then 1500 pounds of sand and 2100 pounds of well graded gravel. The stone should be 3/4" maximum, or 1/2" if that is what is available.

You should get sharp sand; not beach sand.

Ask your supplier what ratios they usually sell for concrete. If they sell material for concrete, they should know what is a good mix for their material.

When you pour the concrete, you might make a screed board with a little arch in it, about 1/4" for a 4 ft walk, so the water will run off.

Shop around. If you can buy a yard of concrete you will appreciate the labor saving and it probably won't cost much more after you add up mateials, mixer rental, and tools.

I need to buy that much material? Thanks, Bob....you ruined my project! Ha. *sigh* Maybe I'll get the delivery and a couple wheelbarrowers....

Thx,
Jason

"I need to buy that much material?"

You calculated 0.8 to 0.9 cubic yards. A cubic yard of concrete weighs about 4000 pounds (145 to 150 pounds per cubic foot).

That is a lot of shoveling and mixing if you are going to do it by hand.

You want your forms all built and your tools all available when the truck comes. Your forms must be strong enough, and carefully leveled at the top, to support the "screed", which is a 2x4 or 2x6 long enough to span the forms and slide back and forth, to make an even surface.

Then you need a "float" which is a piece of wood on a handle that you can work over the surface to smooth it before it is solid enough to support weight. If it's only 4 ft wide you can probably do it with a hand float (about 1.5 to 2 ft long board with a handle like a big drywall tool).

For a sidewalk, you will want to "broom" it so it will not be slippery. And you will want to put in "crack control grooves" as I described in an earlier thread.

The problem with mixing your own is that you will have a hard time mixing it all before the first starts to set up.

63 Sqft 4" thick = 21 cuft

I'm not positive but if memory serves me right an 80# bag of QuickCreete makes 2/3 cuft. If that is correct you neeed about 35 bags giving an uneven base.

You might want to consider going with the quickcrete and getting a bag or 2 of portland and adding a 1/4-1/2 shovel /bag for extra strength. It may be less messy this way.


Your best bet is a company that will deliver less than truck load amounts of mixed ready to pour in forms concrete.

Call the concrete companys as the may be able to refer you to someone.

concrete

You do not want to be in the situation of one person in this area, many years ago, who ordered a load of concrete for his rear patio. He had the forms all set and everything was ready for it. He ordered the concrete, but had to leave before it arrived, so he told his wife to have the driver dump it inside the forms. Several hours later he called the ready mix company and asked, "You delivered my concrete several hours ago. When is it going to level itself out?"

hj said:

You do not want to be in the situation of one person in this area, many years ago, who ordered a load of concrete for his rear patio. He had the forms all set and everything was ready for it. He ordered the concrete, but had to leave before it arrived, so he told his wife to have the driver dump it inside the forms. Several hours later he called the ready mix company and asked, "You delivered my concrete several hours ago. When is it going to level itself out?"

Click to expand...

Funny, funny. Really that would suck, though. I'll probably call around for delivery, I guess. See what I can find out as far as cost goes. Stupid sidewalk.... heh

Thanks
Jason

Some concrete companies will work with homeowners who need a small amount (small by their standards) of concrete and if they are delivering a truck load in your neighborhood and have a tad extra, will make you a good price. Catch is of course, you have to be there ready to handle it and they can't tell you for sure when it might be delivered. Anyway, it's worth a check. Mixing concrete in at home is a beastly job. The cost of premix isn't bad if you can avoid the delivery charges. That's why many places have those U-Cart trailers for rent. Are you absolutely certain there are none of these in your area?

I want it to be here. I searched and searched to no avail. I'm in Columbus, OH, if you care to check my work. I've got access to a Chevy Avalanche so getting here shouldn't be a problem. If I had no truck it would be available.

Thx
Jason