Pouring concrete....

[rtimgray]

Of all the projects mentioned on TBN, for the life of me, I can't figure out why so many people on here are terrified of pouring concrete. I'll grant you it's hard work, but it's not brain surgery. The reason that some guys pour concrete for a living isn't because NASA's not hiring.

Having said that, not even I would attempt a 37' x 20' pour by myself. I would get at least two helpers, because you basically need two people on a screed and one with a rake leveling the pour as you go. If it was going to be poured on a hot day, I would want a 4th to start finishing with a bull float as soon as it was screeded - if it's cool, then 3 should be enough. Assuming 4" thickness, you're only talking about 9 or 10 yards, which should be on truck (at least in my area). If I were doing it, I would break it into two 10' wide pours and do them at separate times, making it actually pretty easy, as concrete goes.

Prices for pouring and finishing in my area seem to be about $1 to $1.25 per sq. ft., making this about a $750 to $1000 adder to cost of the concrete. That's enough for me to break a sweat for a few hours.

But in the end, you decide what your tolerance is, for both hard work and cash expenditure.

Good luck and take care.

 

[RDrancher]

Well thanks for the insult to all concrete guys there rtimgray. They're hiring brain surgeons at NASA now?

I've poured that much by myself before, but not by choice...the help didn't show up. As a concrete finisher by trade (retired) I'd say NO, don't try to do it by yourself. You'll get a much better finish by hiring a finisher and having him bring an experienced laborer or two along. And I will add that all finishers are not created equal. Hire a pro that puts his name on every slab he pours and you'll get a professional finish. Hire a butcher with a bucket full of cleavers and...well, you know.

Excellent points by CurlyDave and others.

Edited to add: Have the finisher come out and look at your form setup before he pours. There's nothing worse than showing up and having to change forms and set pins while the truck is idling out in the street.

 

[mickd]

NOTV8 You got some pretty good advice in the above replies, especially about getting experienced help. I did'nt notice where anyone mentioned that you can have your batch plant add retarder to the mix, that will give you more working time with the load,especially on hot dry days. An experienced finisher can tell you whether to add 1% or 2% depending on the weather, mix design,even the amount of help he has available. Adding water to the mix to gain working time is risky , too much will decrease the strength of the concrete and should not be used as a substitute for experienced workmen or additives designed for that purpose. Good luck with your pour.

 

[sdkubota]

There are chemical retarders that can be added to concrete that slows the initial set. However, once they have expired...it will get hard fast! Anyone that isn't familiar to working with concrete shouldn't even attempt it. It is far to tricky and difficult to get a nice finish. People that do it for a living make it look easy but believe me it is anything but. Hire professionals or you will pay for the concrete, pay to tear it out, and hire professionals to place it again.

 

[greasemonkeyok]

It may look like it, but finishing concrete is not like pouring plaster of Paris in a mold. Lots of things can go wrong, some of which may not show up for years. RDrancher and others above recommending experienced finishers are giving you the best advice.

 

[/pine]

You've already gotten good advice on making the pour...

What I didn't see or see mentioned is "expansion joint" along the existing slab/foundation...

also...without having a form all the way around you can't really screed it off for grade...a bull float is going to be paramount and I would run some strings and add grade stakes that get removed as the pour moves along...this will help avoid high spots and "bird-baths"...

 

[rtimgray]

To be fair, I should have said rocket science. I guess I switched metaphors in mid-paragraph. Although I did some checking, and it turns out NASA does have doctors and surgeons on staff for pre- and post-flight examinations. Whether brain surgery is their speciality, I don't know.

I also discovered that NASA also stands for Nueroscience And Spinal Associates, and they hire a lot of brain surgeons, but that wasn't the NASA I was talking about.

I didn't mean to specifically offend any concrete professionals, I just meant to emphasize the point that concrete work is probably more about physical work than anything else, not that there aren't some nuances and techniques that can both minimize effort and improve quality. By the same token, I probably wouldn't want someone who normally performs open-brain surgery to pour my driveway, although I could probably live with that. If I had a concrete finisher perform open-brain surgery, who knows....

...maybe I'd be better off.

I'd rather have a bottle in front of me than a frontal lobotomy.

Good luck and take care.

 

[greasemonkeyok]

Blisters, cracking, crazing, curling, delamination, discoloration, dusting, efflorescence, low spots, popouts, scaling, and spalling are the most common defects in a finished concrete surface. Now if you are just pouring a barn floor and don't care about the finish, pour it, screed it, and let it set up rough.

 

[EddieWalker]

Most everyone is giving you really good advice. Curly Dave really spelled it out and it 100% accurate in everything he said. Never rely on wire. It is impossible to walk on it, spread concrete and pull it up into the middle of the pad. GURANTEED!!!!

From what I can see, you have a real nice house. Don not ruin it or cut corners on something as important as what your patio looks like. A bad pour will look terrible. By yourself, without experience and a power trowel, you will end up with a mess. You wil also hurt yourself.

When I did my parents pad a couple months ago, I found a finish contrator on Angies List. I spoke to a dozen before hiring, and the guy with all the great reviews and recomendations on Angies list was the cheapest. I've been a General Contractor as my full time job for ten years and I've done this on the side my whole life. The guy I found on Angies List was the best I've ever seen. He charged .50 cents a square foot.

Eddie