Picked a high-lime mortar for my last job and I'm not sure about it

Had to choose between Type N and a high-lime mix for a 1920s brick house in Detroit. The old timers told me to stick with the lime because it breathes better. I went with hydrated lime mixed with Portland, 6 parts sand to 1 part binder. Three months later I'm seeing some hairline cracks near the window headers. Wondering if I should have just gone with standard Type N for strength. The mortar is softer for sure but I'm worried about freeze-thaw cycles next winter. Anyone else deal with this on historic repointing work?

2 comments

2 Comments

olivias881d ago

That "breathes better" advice is solid for older brick. I did a similar job on a 1900s row house in Philly and had the same worry about freeze-thaw. The hairline cracks showed up on mine too, but they never got worse after the first winter.

eric_johnson23h ago

Funny how that works. Seems like half the time with old houses you just have to wait and see what a year of weather does before you know if you're really in trouble.