Just noticed you posted almost exactly the same time and with a similar question. Good luck with whatever happens! Let me know how things turn out. I can't wait to get this finished!

cmanley33,
Moisture in the concrete is the key to the curing process. In hot temps it's necessary to keep the concrete wet so water doesn't escape too quickly. In cold temps this is not a problem but water will grow 10% and in freezing weather concrete can flake or crack when the water in the concrete expands
Discuss this with your contractor. You may want to cover the deck to keep it from freezing and possible for the entire winter season until it has a chance to cure.
I've used straw to cover concrete when the temps get into the teens. But CA temps in my part of the country don't generally stay low for long periods of time. Good luck.

Thank you. He did say that he would cover the concrete with blankets. What about special additives that they put in the concrete, is that something they can do to keep it from freezing? How long does it take concrete to cure? I thought just a couple of days but you are mentioning keeping them covered the entire winter. Thanks for your input.

Curing is somewhat temperature dependent but not as much as you might think. IIRC, it's about 27 days to reach 90% of it's rated strength.

Sometimes, a mason may add some calcium when temps are cooler. It acts like ice melt, get warm when wet, and when the temps drop, helps keep the curing of covered concrete moving along.

Scott

Thanks Scott. So are you saying I am OK to go ahead with the pour or should I postpone until the Spring?

I assume they are pouring a deck. How long has the ground had to settle? Given this is a pool forum, I assume there is a pool involved also. What type, gunite, liner, or F/G?

Scott

I am in Maryland and my pool build was started 4 years ago in October and finished the following spring. I would wait until we are assured of a long stretch of warmer weather. This is a big project and hurrying at this point may cost you dearly down the road. Blankets will keep some heat in and calcium chloride will accelerate the set time. However, concrete takes 28 days to reach it rated strength. Any freezing temperatures may slow or stop the chemical reaction which gives concrete its strength. You can get additional information from ACI, the American Concrete Institute. The time that you will save by pouring now versus in the spring is nominal or nothing. We open our pool every year around the 15th of May, and that is way too early. Unless you have a pool heater, you will not have comfortable swimming temperatures until around the middle of June. Good Luck, enjoy and remember, once the water goes in all the problems disappear.

pooldazed - thanks. i will consider postponing to the spring. I am hoping that once the water is in all the problems disappear. I am ready for the project to be over :)

scott - yes, we are pouring a deck and yes a pool is involved and was started middle of October so the dirt has settled 2 months now. It is a gunite pool.

I'd go for it. Sure beats a mud pit for a back yard. I would hold off on plastering till Spring though.

Scott

Ha! I thought for sure you would say to wait until the spring. I went ahead and told the PB we could go forward with the grading but I wanted to hold off on the concrete until the spring. Thanks for all of the responses. Looking forward to having this project wrapped up in early spring and thanks to the heater...swimming by May!

As a swimming pool and concrete contractor I can say with certainty that you should pour the concrete now. If the contractor is taking steps to protect the concrete and accelerating the initial set then you will be fine.

If you wait until the spring absolutely anything could happen...many of which leave you holding the bag so to speak. Pour now - concrete can be safety poured, finished and cured in the temps you have described.

If you want a second opinion then check out the link about cold weather concrete curing additives

Here is a link that might be useful: Concrete curing additives

Well, at this point we didn't even do the grading today because we got a ton of rain and it was too muddy. He will not be able to grade until next week. He isn't doing anything yet to ready the soil for the pour but I guess I can discuss it with him next week. Thanks for your advice and the link.