DanG wrote:
40 degrees and rising is the standard engineer requirement.
Remove any frost or snow, ground can not be frozen. Blankets if
it is going below 30 for at least the first 3 days.

Sometimes it is just easier to wait for better weather. Cap with
plywood or fill with gravel that is easy to dig back out.


And we have a winner! You only pour concrete in lousy weather if you
HAVE to. Even if you can keep the pour above freezing, it is real hard
to properly prepare the substrate in cold weather. In a garage,
basement, or commercial interior slab, where the dirt work was done back
when it was warm, and it hasn't been raining on it for several weeks,
they will sometimes pour in freezing weather, using additives and
salamander heaters sitting on sheets of plywood. But outside flatwork is
best left until the next thaw. Half-frozen dirt and mud likes to move
around with freeze/thaw cycles, which leads to air pockets or heaving,
which can make the new slab fail. I'll second what DanG said- fill the
hole with pea gravel, and maybe lay a board on top, to tide you over
till it gets warm. People walking on it will help compact whatever
digging was done that you are patching, and when it warms up, you can
just rake out the top 3-4 inches, lay down your mesh, and pour away.


aem sends...