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I think that old timer was wrong about using lime in the mortar
Way back when I first started out in Portland, this 50 year veteran named Hank told me I absolutely had to add lime to my mortar mix for any brick wall over 6 feet. Said it would stop cracking and make the wall last forever. I did it on a big retaining wall job and three months later the mortar was crumbling out in chunks. Turned out the lime was reacting with something in the local soil and breaking down the bond. I had to rip the whole thing down and redo it without lime. That cost me about $2,000 in materials and two weekends of work. Has anyone else had bad luck following old school advice like that?
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elizabethg184mo ago
...so did you ever figure out what exactly was in that local soil that caused the reaction? Seems like that kind of info would be worth knowing before you put any lime in the ground.
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reesemiller4mo ago
Yeah, I actually read something about this not too long ago. There's a lot of local variability in soil pH and organic matter content that can mess with lime reactions. I saw a study from a university extension office that said certain soils with high iron or aluminum content can bind up the lime before it even has a chance to work its magic (which explains a lot of failed experiments). Also, if the soil has a ton of clay, the reaction can be super slow, like months instead of weeks. So it's not just one thing, it's a combo of what's in the dirt and how it's built up over time.
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