Thoughts about concrete (mortar) work in cold weather...

[Erin]

OK, so winter has finally settled in just when I'm needing to get my stem-wall in.    
(I'm going to put a single layer of blocks on the walk-out side of my basement, and then attach my sillplate to that)  But it's cold... 
Now, I realize concrete makes its own heat while curing, but how cold would it be before you'd put it off for another day? 
We've been unusually cold the last few days, but a night time low of upper teens to mid-20s is more normal.  Day time temps can easily be mid-40s to mid-50s. 
Is that warm enough not to cause problems with my cure??

[rwanders]

Mortar work will be somewhat more difficult in sub-freezing weather because the mass would be so much smaller. It still can be done----do your work after the temp comes up in the morning, use warm water for mix if possible, insulate mortar joints with fiberglass blankets and plastic while curing, if REAL cold---tent wall and provide heat source. Mortar should be sufficiently cured in 24-48 hours.

[Erin]

Well I'm not doing much.  It's just a layer to put a single row of blocks on the footer.  And then fill the cores.  And I probably could get it all done in a single day's work. 
Thanks rwanders

[Don_P]

We've been doing it in similar temps here. We've tented the masons work at night and stick a couple of cheap 1500 watt electric heaters under the tent set on their lowest setting. We've kept his water barrel in a plywood box with another heater in there.