Ok the concrete went in about 1.30pm and the slab was finished around 3pm, so how soon could I expect to be able to lay stuff on its surface without fear of leaving marks or divots..? The current temp is about 10C
Hmm, good question. I'd leave a couple of hours it until it gets down closer to zero to avoid marking it, but happy for other's opinions, I'm no expert at this.
well it depends on how wet the concrete was to start with. it looks like your concrete was pretty hard. relatively dry concrete will be hard enough around 2-3 hrs after finishing to lay just some plastic and wat not on top of.
Give it a test with your finger and be carefull with the plastic if you think its still a little wet.
It will set in an hour or two after first pouring. Just try to put your finger into the surface near the edge ever half an hour or so past 2.5 hours from pour. Do it lightly and when it feels very stiff it will be set enough. What time did you pour the concrete?
Ok, we are going out to dinner but should be home around 9 or 10 pm'ish, that will be about 6hrs or so after finishing the slab and the temp will likely be in low single digits by then, so I will check the firmness and lay some plastic and a blanket over it...should deter the kangaroos a bit more too
Looks good Mike. You can strip the outer formwork now too.
Quote:
Originally Posted by h0ughy
looks good - so is this where the picnic table goes in the garden?
Cheers Paul, will do that tomorrow arvo
Houghy, well that will be the line when we leave it behind ..I will grind the bolts off and the gap will be filled with foam and silicone anyway so it will be a nice level round patio, perfect for a small table and chairs for the next tenants and the view is nice from there.
The cost of the non transportable bits and pieces ie concrete, new tools, other materials etc of the observatory has totalled about $700, so if we are here say another 18 months and say I get 2 images per month on average now, then that's about $20/image so it will have been worth it
Great progress Mike. Make sure you align the top of each wall panel of the sirius observatory to near perfection. You may need to use spacers where the walls meet the concrete to achieve this. Failure to do so will cause dome rotation problems.
