Novice concrete question

[kebwi]

When "floating" the foundation and/or hearth after screeding it with a 2x4, do I need to use a metal float or is a piece of wood with a handle on it sufficient? Does it make any difference structurally (does one draw water to the surface more or less than the other, and is that a good or bad thing?) or is it purely aesthetic with regard to the appearance and texture of the concrete (in which case I'll probably just go with the wood since I don't care what the concrete looks like, I'll probably flagstone it later anyway.).

Thoughts?

[Les]

Re: Novice concrete question

You are good to just screed it off. If all goes well, there should be no water there to be of concern. I left mine rough as well, my thinking was that the mortar would adhere to it better.

Les...

[nissanneill]

Re: Novice concrete question

kebwi
after you screed it off with your 4x2, that gets it flat and level but with a rough finish.
Sure it is non slip but if you want it nicer, easier to sweep or mop, flatter for tiling etc. then you need to use a concreting float. A wooden one held flat and used in a circular motion can push the agregate a little lower (when the concrete is wet and soft) and will not bring the water to the surface. A steel trowel on the other hand will bring the water out of the concrete (which won't hurt apart from possibly leaving water marks on the surface). To get the smoother finish hold up the leading edge of the trowel and when the cement is hard enough to walk on without leaving indentations, use a sweeping motion to get that super smooth finish.
If you have excess water, then make up a 1 part portland and 1 part concrete sand mix and sprinkle it over the surface, work it into a slurry with your flat trowel and then when it is a little drier, float it our with your steel trowel. You can add some coloured oxide to the mix to put a coloured surface on your concrete but follow the instructions on the oxide container.

Good luck and watck your back.

Chers.

Neill

[kebwi]

Re: Novice concrete question

Thanks. I always appreciate the thorough advice.

Cheers!