Minimum homebrew mixing/setting temperature?

[kebwi]

I'm not asking about heat tolerance or curing or anything like that. I'm asking how late into the winter one can build an oven. What is the temperature below which I should stop working with homebrew mortar and wait for warmer weather? Basic run-of-the-mill concrete seems to want upper forties, not only while you're working with it, but also the following night or two, which can be problematic even if your daytime weather is well above the threshold. This is data I got off Sakrete's website for example.

Thoughts?

[Les]

Re: Minimum homebrew mixing/setting temperature?

I don't think the issue is with home brew or refmix/heatstop. The problem is water. You cannot allow it to freeze. When concrete/mortar cures, it puts off heat. You can purchase/rent blankets that are made for this purpose. I personally put the build on hold when the temps got to freezing. Add to the fact that I'm a wimp when it comes to cold.

Les...

[kebwi]

Re: Minimum homebrew mixing/setting temperature?

Ah. Hmmm, I'm enclosing the work area under an awning (Seattle + autumn = rain) and I've been steadily building up plastic sides around the awning anyway. If I go a bit further maybe I'll have a "room" I can keep warm with a space heater...or maybe such an enclosure would not hold heat and such an effort would be futile.

I had good success with a space heater under the hearth last night while the hearth sets, but heating above the hearth where the dome is would be much harder because the hot air will go to the top of the awning.

Maybe I could keep the space heater under the hearth, with blankets over the top, and let the heat diffuse up through the slab.

I'm scheming now...

[Les]

Re: Minimum homebrew mixing/setting temperature?

Maybe I could keep the space heater under the hearth, with blankets over the top, and let the heat diffuse up through the slab.

If you are properly insulated, I don't think this approach will work. If all you are dealing with is rain, you should be golden as long as you are dry. Does it freeze much in Seattle?

Les...

[kebwi]

Re: Minimum homebrew mixing/setting temperature?

That's hilarious. Insulation getting in my way. Good point though. As for freezing, yeah, in January it'll get that cold. We had some hellish snow last year (unusual from what I've been told, I haven't live here too long yet).

I see your point though. It's all about the freezing temps. I'll keep that in mind as I go.