I am hoping to pour the first footings for my new house this week.  The footings are 2 feet wide and 1 foot deep with a layer of reinforcing mesh 3 inches from the bottom.  The starter bars are to be wet set in the footings with about 8 inches set into the concrete and 18 inches sticking out of the top.

This is my first experience of doing anything serious with concrete and I have some very basic questions.  We will pour the concrete into the shuttering formwork, roughly level it by dragging a piece of wood along the top of the shuttering and then vibrate it.  Once it has gone off a bit we will trowel the top to get it completely smooth and then insert the starter bars.  My questions are:

1. How long should I wait before I trowel the top?

2.  How long should I wait before I insert the starter bars?  Presumably it needs to have gone off a little bit so that they don't just fall over but still needs to be liquid enough to grip the bars.

3.  Should I cover the concrete overnight?

I don't know if it helps but the temperature when it is poured is likely to be about 44 F, dopping to about 40F at night.

Thanks very much.

Andrew

Andrew, a couple of minor suggestions... I would vibrate first and then level with the board because the vibrating is going to have somewhat of a leveing effect. Not a big deal it's just that if you level first and then vibrate you might find that the settling will require the addition of more concrete and so on. You might try it both ways. I don't recall the size of your rebar from the other post but (here) the code is 40 diameters. I know you are metric but that's 20 inches for #4, 25" for #5 and 30 inches for #6 etc. Technically, you might should have 40 diameters below as well but i suppose that's up to your engineer.

1) Assuming you are pouring about a 4 slump or so you should be able to trowel the top as you go without issue.
2) Unless you've already cut these to 24" you might make them a few inches longer and put a 90 degree bend on the part that is embedded in the footer. Particularly if you only have one foot to work with. That will also make it easier to you to set them while it's still a bit wet. If you let it get a bit dry you will want to move the bar up and down a bit to close the hole around the bar (whether you add the bend or not). You'll get a quick feel for how long you need to wait to keep them at the right height. Based on the temperature you might need to wait a half hour or more (again depending on your slump).
3) I wouldn't bother covering the concrete unless theres some small chance that it could freeze and then it would be necessary.

Good luck. I"m sure you'll do fine. Regards.

Thanks very much for your help. AA

I agree with the additional length and this could be done a bit easier by placing the bars on a form board prior to the pour.  This would give you an accurate depth and spacing as well.

Hi,
I think you will wait for an hour for that,,...
Our you read the direction of application for that product...

Thanks for the suggestions.