Switched to lime mortar after fighting with Type N on an 1890s row house in Baltimore

I always used Type N for everything, figured stronger is better. But on this old row house, the brick was soft and crumbly from 130 years of weather. The lime mortar I tried on a test patch was way easier to work with and didn't crack the brick faces. Talked to an older mason at the supply house who showed me how it breathes and lets moisture escape instead of trapping it. Saved me from redoing half the wall after three freeze thaw cycles showed damage from the hard stuff. Anyone else made the switch for historic work or do you stick with modern mixes?

2 comments

2 Comments

spencer_owens581mo ago

Had the same hard lesson on a 1920s rowhouse in Philly. Took a cracked wall before I realized the old soft brick needed softer mortar.

the_lisa1mo ago

Those Philly row houses are notorious for it too @spencer_owens58. I had a whole section of wall on the rear facade where the type N was basically grinding the brick edges down every time it moved. The lime mix I used on that same wall three years ago hasn't shown a single crack, and the brick faces are still crisp. It's wild how much softer that old Baltimore brick gets after a century of soot and rain.