That mortar mix ratio my grandpa swore by finally clicked

Was chatting with an old timer at the supply yard in Tulsa last week. He said he always does 3 parts sand to 1 part Portland, no lime, for anything load bearing. I always added lime cause that's what the book said. Tried his way on a retaining wall Saturday. Man, that set up stiff and fast. No sagging on the face. My joints came out cleaner too. Still a bit nervous about flex cracking though. Anyone else ditch lime or stick to it for certain jobs?

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mark_mitchell2mo ago

My grandpa did the exact same thing, no lime ever, and he built retaining walls in the 60s that are still standing behind a church outside of Waco. I fought him on it for years until I did a mailbox base with his mix and it just felt different, way more solid. The flex cracking worry is real though, but I figure if you pack a good gravel base and keep the wall under four feet, that stiffness works in your favor. Lime helps when the ground shifts a lot, like around here in the clay, but for a straight gravity wall his mix feels like overkill on the flex side. I still keep a bag of lime in the truck for footer pours or anything tied to a structure, but walls get the no lime treatment now. Just make sure you wet the blocks good before you set em, that stiff mix grabs hard if the face is dry.

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the_linda2mo ago

That Waco story hits different, I read somewhere that old Texas mixes relied on the local dirt itself for binding since lime was too pricey to haul back then. Good point on wetting the blocks though, my neighbor skipped that once and his mortar crumbled within two winters.

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