Quick tip for mixing mortar in cold weather

I kept getting crumbly mortar on my basement block wall until a guy at Beaver Lumber told me to warm the mixing water to about 40 degrees Celsius before adding it. Tried it last November on a cold afternoon and the mortar stayed workable for a full hour longer than usual. Anyone else run into this issue when working through an Alberta winter?

4 comments

4 Comments

the_robin21d ago

That bit about warming the water to 40 degrees is interesting. Did you test it with different cement brands or just whatever was cheapest at Beaver Lumber that day? I've heard some say warm water can make the mortar set too fast if you're not careful on the temp.

felixlee21d agoOG Member

Huh, good catch but it's actually the other way around. Warm water slows down the set in cold weather, doesn't speed it up. I tested it with Portland and a couple other brands, got the same result each time. Just stick to the 40 degree mark and you'll be fine.

emery1910d ago

Oh I'm embarrassed to say it was whatever was cheapest that day... I think I grabbed a bag of something from the back corner with a picture of a castle on it? Not exactly scientific testing on my part. The warm water trick worked fine for me but I was also working in like -5 weather so flash setting wasn't really a concern. Your point about being careful with the temp is fair though... if someone's in milder cold weather that 40 degree water could definitely sneak up on you if you're not watching the clock.

henderson.wesley10d ago

Tbh I read something similar in a cold weather concrete guide from the Alberta government a while back. They said warm water helps but dont go above 40 degrees or you risk flash setting. Sounds like that Beaver Lumber guy knew what he was talking about.