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View Full Version : Help! 2 days before they pour Concrete Patio directly on dirt!


Smigler
07-28-2007, 04:15 PM
My concrete contractor is constructing an 800 sq. ft. patio here in Utah. After removing the sod, and packing down the "fill" dirt from the original home construction (6 years old) with the skid steer, he said that they can pour directly on this surface.

The picture is 2 days after the rain showing where the water is still evaporating at the edge of the grade and the rebar that they put down. It has rained once (the grade seems ok) and the dirt is now very hard, but it varies in texture from organic to primarily gravel near the house and under the previous steps and stair landing. You can also tell the difference in soil composition by how quickly the water has evaporated.

I am in a hurry because they will be pouring this week and I want to know if this is an acceptable practice and what are the problems with it and what would be the benefits of laying down a consistent gravel base. This is just a patio, so I will never be parking on it or putting anything heavy on it. We do get several freeze/thaws a year. Should I request that the gravel be included in the cost as it was something that should have been done from the beginning?

Thanks in advance!!

newz7151
07-28-2007, 04:35 PM
Not in this business, but, sure doesn't look like much steel. Also, are there chairs under it or have they just not put them in yet?

Smigler
07-28-2007, 04:51 PM
They have not put the chairs in yet. As far as the rebar is concerned, I received about 5 quotes for this job and only one (this one) recommended the rebar at all. It's every 4 ft. or so. If I need more, then I will have them do it.

mverick
07-28-2007, 05:20 PM
If you have freeze thaws. Put gravel down. 4in. Your drainage underneath with have something to move/adjust if it get's water and freezes. I usually don't put in rebar either. Or tie it to the house. Some do.

One thing I will guarantee you. It will crack. It is concrete and no matter what you do. It will crack. The bar helps tie it together. If they don't put the chairs in it's worthless though. Bar will always go to the bottom. And, I'd lay the net instead of the bar. More to net and you're not looking for the strength of the bar.

They have done this for years. I know people who put down sand. Which holds water and still use it for fill. I use 4in of 3/4 gravel. grade 8 holds water too...

Oh, since he doesn't put down gravel that would be why he was cheaper. For 4in of 3/4 clean to be excavated and laid down you're looking at another $1800 or so.

mverick
07-28-2007, 05:34 PM
I decided not to tell the way to build it.

mverick
07-28-2007, 05:35 PM
They have not put the chairs in yet. As far as the rebar is concerned, I received about 5 quotes for this job and only one (this one) recommended the rebar at all. It's every 4 ft. or so. If I need more, then I will have them do it.

Oh, why 5 quotes? What where all the prices and the one you chose?

Pay someone that knows what they're doing. It costs more. But you get a better finished product.

Smigler
07-28-2007, 06:10 PM
Oh, why 5 quotes? What where all the prices and the one you chose?

Thanks for the feedback mverick. To answer your questions:

yes that is one layer of masonite, but we were looking for the flowing "organic" look so as long as the edges are square, I don't mind if it bows out a little.

As far as the quotes are concerned, why five quotes? Well to make sure that everyone was at least in the ballpark. We DID NOT go with the lowest bidder, in fact he was one of the higher 2 bids. Unfortunately, around here it is very difficult to actually get a formal written quote. We have a real problem with gypsy bands of tongans and samoans, local and out of California (all named Sione for some reason) that share 1 business license doing unprofessional work. (a tip off is that they do not want to submit a written quote, they share a business license under a cousin's name, and want to start the job immediately). That means that most of the "legitimate companies" are very busy doing commercial work and at this time of year do not have much time for residential work. So, of the written quotes by legitimate established companies we chose this contractor.

We chose him based on his overall professionalism and references. He was also the most thorough in breaking out his quote. He called and visited when he said he would. He was prompt in our meetings. He gave us references that we could check out (as was mentioned on this site before we didn't just check the newest jobs). He seemed to be the most knowledgeable about stamping and staining.

As far as pricing is concerned, the TOTAL prices ranged from $7700 to $8800 with his near the high end of this range. The patio will be 800 sq. feet. These prices included Prep, pour, finish, stamp, stain, fibermesh, rebar, skid steer rental for sod removal and removal of 2 existing 4x8 concrete pads, grading, grading, concrete pump rental, and all forming.

Without the stamp and staining the flatwork is going for about $4 sq. ft. here in Utah and there is too much business. That is why we are seeing a big influx of shady (no pun intended) characters coming in from Las Vegas and California.

Do you see a huge problem with pouring directly on the dirt?
Thanks again for taking the time to educate.

Smigler
07-28-2007, 06:11 PM
Would you pm me with the sample pricing breakdown for base that you had broken out before you removed the post?

mverick
07-28-2007, 06:24 PM
$4 a sq foot is Cheap, Cheap, Cheap. no wonder no names do that. $7-8 is low here. For all the extra you quoted. $14 for the stamped and colored. For the tear out and Rock another $2000 to $2500.

Nothin for the soil to expand contract in means it will push the concrete. Crack and heave.

For the pad you need rock and drainage. Under the rock put down fabric so the dirt wont perculate into it.


Your masonite will bow. A lot. You need heavier bracing for it. Even if you want it to bow.

Smigler
07-28-2007, 07:20 PM
$4 is the going rate here. I explained that we did not go with the no-names, but only accepted quotes from the large established companies in the area, members of the BBA, locally owned for at least 5-10 years, and parade of homes sponsors were the minimum requirements.

6.0 engineered concrete is about $111/yd. delivered and the road base is priced as below with a $50 delivery fee:
Product Price per ton
6” minus, Pit Run $2.50
3/8” Crusher Fines (Breeze) $2.95
3/8” Slurry (Type II) $5.00
3/8” Washed Chips $12.75
1/2" Washed Chips $11.75
3/4” Road Base $3.85
3/4" Rock $6.95
3/4” Washed Chips $10.75
1 ½” Road Base $3.20
1 ½” – 3/4” Rock (Ballast) $5.15
1 ½” – 3/4” Northern Sunset $8.25
For wet processed material add- $1.50

I am not sure why there is such a disparity in pricing between here and there, but these prices were not the low-ball no-names. Those jokers were talking about $5-6K for everything. Maybe there is more competition here. So stamped and colored with simple excavation is about $9-12 /sq.ft.

Dirty Water
07-28-2007, 08:26 PM
For what its worth, I used to pour concrete for a living.

You don't need chairs if you know what you are doing. We always had one grunt lifting the rebar while pouring. We also always used bar or grid, and poured with fibermesh concrete.

With proper expansions joints, you will have minimal cracking.

Out here, base is just compacted dirt. This is concrete, its not going to settle, and gravel will heave just like dirt.

In other words, I think your just fine.

Smigler
07-28-2007, 09:21 PM
For what its worth, I used to pour concrete for a living.

You don't need chairs if you know what you are doing. We always had one grunt lifting the rebar while pouring. We also always used bar or grid, and poured with fibermesh concrete.

With proper expansions joints, you will have minimal cracking.

Out here, base is just compacted dirt. This is concrete, its not going to settle, and gravel will heave just like dirt.

In other words, I think your just fine.

thank you for your feedback and help!! :clapping:

mverick
07-28-2007, 11:01 PM
For what its worth, I used to pour concrete for a living.

You don't need chairs if you know what you are doing. We always had one grunt lifting the rebar while pouring. We also always used bar or grid, and poured with fibermesh concrete.

With proper expansions joints, you will have minimal cracking.

Out here, base is just compacted dirt. This is concrete, its not going to settle, and gravel will heave just like dirt.

In other words, I think your just fine.

Yep, that's the old school way. But, gravel doesn't heave just like dirt. If the dirt heaves into gravel there are voids. It will move a little. There ain't no voids in concrete other then the air entrainment you specify. And that ain't gonna give.

And, I've ripped out many with rebar that did it the same way your talking about. Most of the rebar was at the bottom of the concrete. NOT in the middle. After lifting it. It tends to sink. Use chairs. There cheap insurance.

From my understanding. It's hard to get the sand and fines for concrete is why it's expensive. A lot of sand gets shipped oversea's, from what I was told. Guy who owns a concrete curbing machine making business in Utah told me this. His sand was High and his concrete was $122 a yard. Here, it's $80 and if you get a whole truck no delivery. Some charge an extra $50 for washing out color. Plus an extra $50 to $80 for a short load Plus $50 for delivery. You do it a lot. No delivery and no short load or washout fee's. Here we have the Mississippi River. And there is sand all over. Plus rock quarries within 10 miles.

And, fibermesh just helps a little. It ain't all it's cracked up to be. LOL... Testing has showed that. Rebar just holds it together if it cracks. And if done right, extends the load into other concrete making it stronger.

We have guy's here that pour on dirt. Uncompacted and compacted. Been doing it for 20 years. Lot of heaving concrete in the older areas. And that happens to be why. I do it the new way. I like things to last. But, it does cost you more.

Here 8-9 yards is a full truck.
Color depending on which one can take 3 bags per yd. Between $40 and $100 a bag. The expensive was a green. I haven't used it, it was ugly. I like color throughout the concrete. Not the trowled in. The 5000psi surface troweled in. I know what this stuff is and it's funny. Easy to make it yourself and everyone would have been doing it that way if it was better a long time ago. I can make a 5 gallon bucket for $15. So, I use integral color with a color on top pressed in for the release. The liquid release is a rip off. You can use other liquids for far cheaper. Work just as well. The powdered releases are easy to make also. As are the acid stains. Just gotta know your chemicals.

I went to school for Chemical Engineering and worked in manufacturing on the line and in the plant for 18 years. While getting my business going. I know chemicals. Oh, I still pour and finish concrete. Run the curbing machine. Run the bobcat and excavators. Drive the trucks and the concrete buggies. I don't sit on my butt and talk about it.

Smigler
07-29-2007, 01:28 AM
Mverick,

Thanks for taking the time to post and to give me alot to think about and discuss with my concrete guy. Very kind of you.

Yes, the colors can be expensive. I called around and was told that the reds are expensive and difficult to get right. I think that I was told that they mix the colors in at the plant and it comes in the truck pre-mix and then the releases are done onsite.

I will have my concrete guy put the chairs in, that's too easy of a job not to do; like you said "cheap insurance".

For an accurate comparison to what you guys are paying, here is the current price list for our biggest cement supplier in Utah:

http://www.genevarock.com/pdf/Prices-Concrete.pdf

As far as the cement pricing is concerned, I work with Holcim (probably the largest supplier of cement in the world; they employ 90k people worldwide) but on the engineering and design of mills, not cement. While the 3 gorges project was going on in China a few years back about 90% of the Colorado cement was being sold to the Chinese.

Last item, I think its interesting that we do not have any rear discharge cement mixers here, I asked someone and he told me that the front discharge trucks were invented here in Utah. I looked it up on wikipedia.org under "cement mixers" and sure enough "The first front discharge mixer was designed and built by Royal W. Sims of Holiday, Utah". Interesting!

back to the subject: Would you suggest more rebar? That's another item that I think would be cheap insurance if it needs it.

mverick
07-29-2007, 04:21 AM
Mverick,



back to the subject: Would you suggest more rebar? That's another item that I think would be cheap insurance if it needs it.

We have mostly rear discharge here.

You aren't putting a load on it so I wouldn't think you need more rebar. Only reason to spec out rebar is if putting a large load on it. I'd put the metal net in it and leave it like that. But that isn't necessary. Cheap insurance. Think a roll cost $100 or less here... Plus around $150-200 to install. Cutting to fit and wireing together...

zedosix
07-29-2007, 09:00 AM
Looks like shoddy work to me, no written quote? What about warranty? Oh right he told you he would stand up to his word if there is a problem.

ChampionLS
07-29-2007, 03:31 PM
I think the high cost of Concrete is the actual Portland Cement. I watched a TV show on how they make that stuff. Look it up.

Rebar will help hold it together, but it does need to be centered in the slab, otherwise the concrete will not "mold" around it for anchoring. Also- that's a big slab!. They could saw cut some expansion joints a day later. That will help- and the joints will only be 1/8" wide.

I see plenty of jobs poured on dirt- even state work. I don't think adding stone will stop or slow any cracking. The integrity lies within the slab it's self.

PerfiCut L&L
07-29-2007, 11:45 PM
I dont do concrete pads (professionaly) but I have poored several at my own home. Current and past. Most recently a 12x12 for a hot tub, and a 3x8 walkway.

It seems to that there should be more steel. I always use rebar for the rough shape and then again about every 12"-18" (on center), and then use a welded wire mesh for fill in the rest of the area. Poored directly over packed dirt. Varying thickness depending on what the poored area is for, generally 4"-6" thick. Seems to work for me.

But like I said, I dont do it for any of our customers, and I dont know enough to give any kind of right or wrong advice. I just know what Ive done and how it works for me.

Best of luck.

Sierra Landscaping
09-03-2007, 02:22 AM
Those forms will balloon out when the concrete is poured as they appear to be very flimsy. Looking at the pic shows that the width of the sidewalk is uneven and will be uneven ~ even more when the concrete is poured.

I would think you would need more rebar in the current grid that is shown on the pic. 18" apart with #3 rebar should do just fine.

Never poured directly over dirt and/or sand - we always use 3/4" A/B for our base and vibra-plate it down with a Whacker or a jumping jack!

To be honest with you....dont like the craftsmanship that I see in the pic. It is hard to tell but I can only assume that the grade for the drainage goes from the back of the house to the end of the patio.

Best of luck...would love to see a pic after the job is done!!