What is the lowest working temperature advisable to lay concrete and build walls please?
The National Building Code of Canada requires ther following for Cold Weather Concrete Requirements: (1) When the air temperature is below 41 F, concrete shall be (a) kept at a temperature of not less than 50 F or more than 77 F while being placed, and (b) maintained at a temperature of not less than 50 F for 72 hours after placing. It is not difficult to maintain this temp with concrete as the chemical reactions during concrete curing produces heat. Once the concrete is placed just cover it with a tarp. If it is really cold, use a propane heater under the tarp. Houses are built all winter long here in Canada so it is no problem to pour concrete in cold weather. To prevent honeycombing of the concrete just make sure you keep it covered.