I laid some (50) firebricks with refractory mortar (pizza oven) yesterday. It was 15 degrees warm outside and the forecast was for 5 degrees above zero overnight. But when I woke up, it was -3. Does this mean it got damaged overnight and that I need to tear it down and redo it?
The stones heated up during the day and retain the heat well, (a lot of weight that needs to cool down). Then the mortar also burns, which generates some heat as well, so I think it's fine.
