Finishing a small concrete slab (first timer)?

Question

I have my form set, gravel in, purchased portland concrete in 60 lb bags, am pretty sure on how to mix it, my question is how long do I wait before I smooth it out and then how long before I can edge it? (slab is only 9 sq ft)

Answer 1

depending on how wet you make it.  You'll need to either rent a few tools or make a float.  I'd be guessing it's only a 3x3 or something like that.  You can float it off immediately.  Use either a magnesium or wood float.  You can make a wood float with a smooth 1x4 with a block of wood  screwed to it for a handle(like a piece of deck board with rounded edges)  As it sets, water will pool at the top.  After the water starts to go away, but it's still semi-soft(you can put finger indentations in it, but you can push your finger in) put the edge on it.  If you want to put a 'broomed' look on it, use a paint brush with a stick taped to the handle, or use a soft bristled broom, laying it flat so you use the sides of the bristles, not actually 'sweeping' it.

Answer 2

Make sure you have a screed board to knock down the concrete and level it to the forms. That can be a 2 X 4 that is long enough to extend over the edges of the form. Start pouring in the concrete at one end and work it down level as you go. Get it as flat as you can by putting more in where you have low spots.

Once all the concrete is screed off and the forms are full, you should float the surface to make it smooth. You can wait a bit before edging it, but don't wait too long. Wet concrete works best.

I would rent a nice float with extension handle rather than  buying it.

Answer 3

First of all, you do NOT want to pour portland cement by itself.  Portland is just one of the ingredients that make up concrete.  Concrete also contains sand and gravel.  That's where concrete gets its strength.  This slab will crack and flake with just portland.

If you pour it with concrete, you will strike it off with a 2x4, using a sawing motion.  Then, using a magnesium float, you will float the entire surface to "close it up".  Go have lunch, then you can come back and work the pour.  Start by refloating it with the mag, then you can edge it.  If the pour is outside, do not use a steel trowel on it.  Float it again until you can feel it almost stiff, then lightly drag a broom across it in one direction.  Alternate between grooming and edging until you have the finish you want.  cover and let it cure for a day or two, then strip the forms.  Good luck.