TIL lime mortar from 1800s is still holding up better than some modern mixes

Was reading an old trade journal from 1892, the kind they digitized for free online. Found a section comparing lime mortar batches in Philly row homes. Those walls are still standing after 130 years of weather. Meanwhile I repointed a porch last spring with a modern mix and it's already cracking in spots. Not saying old stuff is magic, but maybe we overthink the additives. Anyone else ever test lime putty on a small job just to see?

2 comments

2 Comments

holly4726d ago

Ugh, the additives thing bugs me so much. Did you try the lime putty on that porch, or did you just watch the cracks form and regret it? Cause I’m curious if the old stuff actually behaves worse in the first year but catches up later. Or maybe the real difference is the sand they used back then, not the binder. Ever check the grain size on the 1892 spec? That’d tell you more than the lime recipe.

riley5826d ago

Right, "regret it" is about the size of it, I watched that crack form like it was on a schedule. I didn't check the 1892 grain size, but I did check the price of lime putty and promptly decided my porch was fine with its modern fate. The old walls are still standing, sure, but so is my regret, so maybe we're even.