Warning about mixing mortar in cold weather without the right steps

I keep seeing crews around town just adding a bit more water to their mix when it's cold out, thinking it will help it set. That is a huge mistake. I learned this the hard way on a job in Springfield last winter. We had a morning temp of 35 degrees and the mortar never properly cured. It stayed soft and crumbly, and we had to tear out and redo an entire chimney base, costing us two full days of labor. The issue isn't just the water, it's the temperature of the sand and the water itself. You need to use warm water and, if possible, store your sandbags somewhere above freezing the night before. Just adding cold water to a cold mix guarantees a weak bond. Has anyone else had a project fail from cold weather mixing, and what's your go-to method to prevent it?

2 comments

2 Comments

dakotal195d ago

Yeah, that part about the sand temperature really hit home... I read a thing from a mason saying the sand holds the cold way longer than you'd think.

marywells5d ago

Oh man, that's the kind of mistake you only make once. I can picture the crew just dumping in extra water like it's some kind of magic fix. @dakotal19 is right, the sand is the real problem child here, it's basically a big cold sponge. My uncle's a mason and he swears by keeping his mixing water in a heated cooler on the truck. Says if you can't keep your thumb in the water for ten seconds, it's too cold for the mix. Trying to save five minutes by not warming things up just costs you days of rework.