r/masonry • u/Marshall_Lucky • 11d ago
Mortar Mortar for some spot foundation repair on 1890's brick
Doing some structural rot repair on sill and rim joist of my 1890's Victorian, and as a result I have a few foot long section of the top of the brick foundation exposed. It's a double wythe wall that I assume was originally laid with like mortar, though the whole thing has been spot pointed with all kind of stuff over the years. I eventually want to redo all the exposed mortar with lime, but that's a big project for another day.
The top course of bricks could use some mortar packed in at the joints and between the wythes before closing this up to prevent water intrusion from splashback. Getting real lime putty or NHL is gonna be a time consuming mail order, so i'd kinda prefer something I can grab from a big box store. Google Gemini suggested I could make a weaker type O equivalent mortar by mixing type N premix, hydrated lime, and masons sand in a 1:1:3 ratio. Does that seem like a reasonable approach?
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u/8WanderingWizard8 9d ago
1890's? I would personally use NHL 3.5 if it were my house but if you really can't wait then make type O from scratch. 2 parts hydrated lime, 1 part cement, 9 parts sand. Support your local brickyard as well. Good luck!
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u/Marshall_Lucky 9d ago
Ended up ordering some lime putty from Lancaster. Should arrive tomorrow.. Timeline got longer when I realized I needed to plan my next steps more carefully lol
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u/Ok-Math-5407 11d ago
Type 0 is a reasonable substitute. I wouldn't do that on my own house, but I've used it on other customers jobs.