Replies

1. 
   MikeSmith | Dec 28, 2004 11:32pm | #1

   if the deepest reach is 3.5' and you have access to the whole thing , it should be a cinch

   the exisitng slab is one side of the form.. set your outside form so the top is finish grade..

    use a stiff mix.. and pour it proud.. screed it with a sawing motion the whole length, when it gets plastic , finish it with a steel trowel..

   if the front will be a finished , exposed  edge,  tap your forms to get the honycomb out, use and edger

   keep a bucket of mix  handy to top  any imperfections as you finish

   you should be able to frame on it in a week

   Mike Smith Rhode Island : Design / Build / Repair / Restore
1. 
   tab1 | Dec 29, 2004 05:00pm | #2

   <it should be a cinch>

   That's my hope--just so rarely seems to turn out that way!  <G>

   Thanks.

   Thon

2. 
   rez | Dec 29, 2004 08:13pm | #3

   Would you recommend using a vibrator to lessen the air voids before screed? 

1. 
   MikeSmith | Dec 29, 2004 08:53pm | #4

   no.. i assume the front is a thckened edge..

    i'd rod it and thump it.. the screed should fill the remaining voidsMike Smith Rhode Island : Design / Build / Repair / Restore

1. 
   tab1 | Dec 30, 2004 03:01am | #5

   Yes, it's more or less a FPSF slab.

   What's this rod and thump stuff???

   Thanks.

   Thon

1. 
   brownbagg | Dec 30, 2004 04:18am | #6

   rent the bull float.

2. 
   MikeSmith | Dec 30, 2004 04:34am | #7

   and the guy who kinows how to use one ?Mike Smith Rhode Island : Design / Build / Repair / Restore

2. 
   slykarma | Dec 30, 2004 04:51am | #8

   Check how wide the bull float is before you rent. If it is wider than the form, forget it. Bull floats don't work well if they are riding up on a form edge. They are great for large areas but careful screeding off and floating by hand will do the job. A magnesium float is the best for this but next best is a wood float you make yourself. Steel trowel later once the concrete has cured enough to walk on but still leave slight imprints.

   Cover the slab once you're finished and protect from freezing. Leave the forms on for an extra day or two before stripping. Should be OK to frame 5-7 days after pouring.

   You'll need one helper to assist in placing and levelling the concrete. If you are wheelbarrowing the concrete, avoid pivoting the front of the barrow on the top of the form as it can force the form down and cause a low spot in the slab edge.

   Keep an eye on the area up to 6" from the edge of the existing slab. The old concrete will absorb some of the water from the new, causing it to set up significantly faster. You'll want to edge this part first before it becomes too hard to cut the edge.

   Good luck!

   Lignum est bonum.
1. 
   JTJohnson | Dec 30, 2004 06:53am | #9

   Also don't play with the concrete too much. There is a point where you have brought too much cream to the top. Perhaps call in a couple of favors to get someone over there that has finished before. And if all else fails, what I was always told when I began is this. "Looks good kid, hit it with the broom."Jeremy

1. 
   slykarma | Dec 30, 2004 08:09am | #10

   "Too much cream to the top" is bad indeed. It means you're tooling in bleed water, which increases the water:cement ratio at the surface. This results in a very weak, powdery surface. Leave the bleed water alone and let it evaporate off. Should be no further tooling until it just gives under hand pressure.

   WallyLignum est bonum.

1. 
   tab1 | Dec 30, 2004 04:04pm | #11

   Thanks for all the tips.  Thought of one other thing:  The Concrete book talks about control joints.  Sounds like I should have one/some in this 3.5 x 24 foot rectangle?

   Thanks.

   Thon

1. 
   brownbagg | Dec 30, 2004 04:22pm | #12

   cut it every eight feet. cut it deep 1/4 the thickness, bull float long ways not short. do not play wiyh the concrete, pour dry, have fun. I think everybody need to pour a slab once in there life. I like to pour mud to grade then wait about thirty minute before bull floating