Vent: Used a different mortar mix on a chimney repair and it set way too fast

I was fixing a chimney in the rain last week and swapped my usual Type N for a quick-setting bag I had left over from a different job. The stuff went off in under 20 minutes and I had to rush the whole top course. What do you all do when the weather messes with your mix choice?

3 comments

3 Comments

mary_kelly2mo agoTop Commenter

Honestly, I used to just grab whatever mortar was on hand to finish a job. Then I had a patio repair turn into a total mess because a "fast set" mix went hard in the bucket before I could even spread it. Now I check the bag for the set time and keep a tarp ready if there's even a chance of rain.

tyler_burns661mo ago

My uncle's a mason and he told me to always check the temperature rating, not just the set time. He had a bag of mortar that said it was fine for 40 degrees, but it just turned to mush on a 38 degree morning. @mary_kelly, that tarp is smart for rain, but cold is a silent killer for these mixes. It's not on the front of the bag, you have to dig for that tiny print on the side. Ruined a whole foundation pour because of it.

hill.troy2mo ago

Tbh, this happens with more than just mortar. Grabbing the quick fix because it's right there is a trap. Used a fast-drying spackle once on a wall patch and it went gritty before I could smooth it. Now I read the labels on everything, even glue or paint. That little bit of extra time checking saves a huge headache later.