Question on monolithic slab - Pour all at once?


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Old 05-04-09, 11:09 AM
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Question on monolithic slab - Pour all at once?

Hello
I am moving in to the second phase of the project. Thank you all sincerely who responded to my earlier post on whether to butt concrete slab to the siding. I have decided to pour the slab 7" below the siding. Now I have another question

The contractor quoted to pour all at once - the 15" X 24" footing, 3 feet retaining wall on two sides and the 20 X 32 feet slab. Is this feasible? Quotes received from other contractors split this into three days – one day each to pour the footings, wait for some time, and than pour the retaining wall, back fill, compact and finally pour the slab on a separate day.

Is this acceptable practice- Pouring all (footing, retaining wall and slab) in one pump?. I am concerned that it might develop cracks since this would be a one huge piece of structure. Also I thought that the better idea is to pour the footing first and let it get cured and than pour the rest since they all sit on top of footing. Now the guy who quoted monolithic slab is the lowest quote, also has excellent reputation, so I would like to know if this is a correct way.

Please enlighten me on this. Thanks
 
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Old 05-04-09, 02:06 PM
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You can do it either way. The monolithic slab is perfectly fine if the guy has the help to do it and the forms stay put and don't bulge. I'm sure he knows what he's doing.
As far as cracking...it will. Either way you do it. Just make sure that whoever installs it cuts in some crack control joints so it cracks where YOU want it to, not randomly throughout the slab.
I used to do a lot of monolithic slab/footings with no problems. Good luck.
 
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Old 05-04-09, 11:55 PM
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The contractor quoted to pour all at once - the 15" X 24" footing, 3 feet retaining wall on two sides and the 20 X 32 feet slab. Is this feasible? Quotes received from other contractors split this into three days – one day each to pour the footings, wait for some time, and than pour the retaining wall, back fill, compact and finally pour the slab on a separate day.
Bold above is the best and proper way to do this especially if it freezes there. The reasons.....

To pour a wall and vibrate that and the one side has been cut out for floor to meet wall I feel is nuts. To keep Crete from slowly going under that form is a full time job for a person for some time not to mention no expansion joints,

I used to do a lot of monolithic slab/footings with no problems.
As Pecos mentioned all at once with now wall is one thing but add the wall all at once is a nightmare.

Pour the footer and the wall can be done at once if you have your snap ties low enough and don't pour to juicy. The problem is no kicker at the bottom for stable plumb form,.

I would pour the footer then form the wall pull forms that day and rub up.

Now you have a wall to snap a chalk line for height on inside slab and felt expansion joint. For the slab I use screed rails and screw felt expansion onto the screed rails and the rails are 1" lower then the felt. NOW you have real expansion joints and can grove between them. Again all at once is begging to crack wherever it wants. Om a side note whats in the works for retaining wall drainage behind the wall?
 
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Old 05-05-09, 04:21 AM
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Here is a link that may give you some ideas:
http://www.eere.energy.gov/buildings...s/db/35017.pdf

Installing the foundation is not the time to rush the job.

Bud
 
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Old 05-05-09, 11:22 PM
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Originally Posted by Bud9051 View Post
Here is a link that may give you some ideas:
http://www.eere.energy.gov/buildings...s/db/35017.pdf

Installing the foundation is not the time to rush the job.Bud
It not a basement. its a partial sunken patio with a knee wall

Don't sweat it. Its hard to believe what some contractors come up with for the customer
 
 

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