Mortar went off way too fast in the heat last Tuesday, lost half a wall

I was laying a garden wall out in Phoenix last Tuesday and the temp hit 108 by 10am. Mixed a fresh batch of mortar and by the time I got 12 blocks set, the stuff in the tub was already stiff as a rock. I ended up tearing out about 8 blocks and remixing, which put me 3 hours behind. I tried adding a splash of water to loosen it back up but that just made it weak and crumbly. How are you guys handling mortar when it's this hot, do you mix smaller batches or is there some additive I should be using?

1 comments

Log in to join the discussion

Log In

1 Comment

masonm851mo ago

Adding a splash of water to loosen it back up" yeah that never works, once Portland cement starts setting you can't bring it back. The water you add just sits there and kills the bond. But the real fix is what you mix with, not the mortar itself. In that kind of heat you want ice water in the bucket, not cold tap water. Dump a bag of ice in your water barrel and mix with that. It buys you a solid 20-30 minutes of working time. Also keep your block wet. Soak them down with the hose before you lay, because dry block sucks the moisture right out of the mortar. A wet block and ice water together and you can actually get a full course done before things go south.

7