patb86•1mo ago

Changed my mind about reusing old brick after seeing a 1990s retaining wall job

I used to think reusing old brick was always the way to go for character. Then I tore down a retaining wall built in 1994 last month and saw how the salvaged brick had started spalling badly after just 28 years. The original builder had mixed old soft brick with modern mortar that was way too hard, and it caused the faces to pop off over time. That 3 hour demo taught me that mixing old and new materials without checking the psi rating first is a recipe for failure. Now I always test the old brick hardness with a hammer tap before I even consider reusing it. Anyone else run into issues matching mortar strength to antique brick?

2 comments

2 Comments

jordan_webb491mo ago

Yeah the hammer tap test is a good call, I started doing that after I had to rip out a whole fireplace surround that was spalling. I also soak the bricks in water overnight before using them with lime mortar to make sure they dont suck the moisture out too fast. That and matching the mortar strength has saved me a lot of headache on old brick jobs.

margaret991mo ago

I hear you on that. I've had my share of heartaches with old brick too. Soaking them overnight makes a world of difference, I started doing that after a chimney repair went sideways on me. @jordan_webb49, that hammer tap test is a lifesaver if you've ever had to deal with spalling later on - it catches the weak ones before they cause trouble. Matching the mortar strength is key, I learned that the hard way when I used a modern mix on a 1920s house and it cracked all over. It's nice to know someone else is out there doing it the right way, not just slapping on whatever bag of mix is cheapest. Keeps those old places standing for another generation.