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Tried switching from lime mortar to Type N on an old house last spring and it cracked right through the brick. | Bricklayers - Vivisector

thomasgonzalez•2mo ago

Tried switching from lime mortar to Type N on an old house last spring and it cracked right through the brick.

Worked on a 1920s row home near Boston and figured modern mortar would hold up better. Ended up having to chip it all out and redo it with lime, cost me an extra 600 bucks in material. Has anyone else run into trouble mixing old and new methods on repair jobs?

3 comments

3 Comments

lunar892mo ago

Youre missing the point completely. Lime mortar is supposed to be softer than the brick so it can move and breathe. Type N is way stronger and traps moisture, which will blow the face off your bricks in a couple of freeze thaw cycles. Ive seen guys try this on row homes in Philly and they end up replacing whole sections of wall because the brick spalled out.

leor862mo ago

Is it really that dramatic though? I've seen plenty of Philly row homes that had type N slapped on decades ago and they're still standing. Sure, if you're working on some 1800s soft brick with that stuff, yeah you're asking for trouble. But a lot of those old buildings have had their bricks replaced with modern stuff already anyway. Feels like half the time guys blame the mortar when the real issue is the brick was already shot to begin with.

murray.robert2mo ago

Haha yeah I learned that lesson the hard way too. Tried using type N on a 1910s brick garage out back, figured it would be fine since the brick looked pretty hard. Three months later I had a brick face sitting in the grass that literally popped off like a bottle cap. Ended up spending a weekend chiseling out all that new mortar and patching it with lime, which was about as fun as it sounds. My back still reminds me of that job every time it rains. At least the extra cost for lime was less than the therapy bill for staring at cracked brickwork all winter.