Blew a mortar joint on a retaining wall yesterday

Tbh I was laying a retaining wall out in Fairfax and one of the mortar joints just let go around 3 PM. The whole top course shifted about 2 inches before I caught it. Had to pull out 12 blocks and re-lay them after mixing a fresh batch. Absolute headache, but I figured out my mix was too dry since the temps dropped faster than I expected. Has anyone else dealt with mortar failing on a wall after a sudden temp change?

2 comments

2 Comments

the_keith24d ago

Tbh that sudden temp drop is a killer for mortar work, especially when you're out in Fairfax where the weather shifts fast like that. I've had it happen on a patio where the top layer just crumbled because I didn't account for the wind picking up in the afternoon. Mixing a little hotter with less water on cooler days is the move, but even then you gotta keep an eye on the clock. Sounds like you caught it before it turned into a total disaster though, which is better than having to rip out a whole section the next morning.

wesley_grant3324d ago

Ngl I gotta disagree with you a little on mixing it hotter when it's cold out. In my experience that just makes the mortar flash set faster and you end up with a crusty top layer that cracks off. I've switched to using warm mixing water instead and it buys you way more time before the chemical reaction kicks in. Also if the wind is whipping like it does in Fairfax you're better off just covering the work with plastic tarps between batches. Saves you from having to rush and make mistakes.