My old foreman in Cleveland taught me a different way to mix mortar for cold weather

I used to just add a bit more water to the mix when it was cold, thinking it would keep it workable longer. That changed after a job in late November where the mortar froze overnight and we had to tear out a whole section. My foreman, Frank, showed me how to use warm water and keep the sand covered, and to add a non-chloride accelerator like Set-Rite. The difference in set time and final strength was huge. What other cold weather tricks do you guys use to keep a job moving?

3 comments

3 Comments

pathenderson17d ago

Frank was right about covering the sand, that's a huge one. I read a thing from a mason up in Canada who said he uses insulated tarps and a little portable heater just to keep the mix area above freezing. He also stressed keeping the bricks or blocks warm and dry before you lay them, because a cold surface will suck the heat right out of your mortar.

eva_thompson101mo ago

Wait, you used to add more water in the cold? That's the exact opposite of what you want, it just makes it freeze faster. I'm shocked that didn't cause a disaster sooner. Adding warm water and covering materials is like the first rule of winter work. Frank saved you from a lifetime of busted joints.

lee.tyler1mo ago

Yeah, I ran that "more water" theory for a solid five winters before Frank saw me and just facepalmed.