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Old 09-22-2006, 11:06 AM
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DDA52 DDA52 is offline
Blood, Sweat & Concrete
 
Join Date: Jun 2004
Location: Bulverde, Tx.
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Ok, as promised, I did pour the slab yesterday and I got some more pics that will help I hope.

First up...Wet Screedumacation.

On this slab, I have a form set on both sides for the end of the porches. The middle was over 22' wide. My mag screeds are 16' long. So to get a line in the middle, we set two stakes with a grade nail near the middle. We then will flatten out the concrete flush with the nail. That is now our grade point. The mag screed is then used to even out the concrete from the form to the point in the middle about two feet wide in this case. We then turned 90° and used that line and the porch form to screed from.

Edit: BTW, those stakes will stay in place until they strike it off right up to them. This is a safety net deal. If the line should get off, they can always go back and reset it with the grade nail.

Two guys were raking excess and filling holes behind the board. The one man is holding the board on the form, while the other uses the wet line to go by. That line has to be held just right. If you press too har, it will dig. If you are too light, the screed will ride up over the line. Either way, your grade will be off.

In this case, they screeded off 3/4 of the slab. The concrete was then ready for the jitterbug and immediately after the bull float and hand work along the perimeter.

You may notice that we are screeding it off although it is not fully poured out. This is what you want to do. Screed off at truck intervals when possible. This was done here at two trucks down. That gave us enough to work easily and also complete the maximum while waiting for the next one. Had the second truck not been there, we would have screeded the one off and waited. Never let the stuff sit toolong, esp in hot weather. It can get away from you if you wait too long. It was not too hot yesterday..about 94°. Too long in this case would be an hour with this mix. Other mixes and conditions will change that figure, so don't use it as a rule...use this: Don't wait too long..get it done asap.
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