Overheard a foreman say that lime mortar is a waste of money on modern homes

I was on a job in Portland last month and this old foreman was telling the crew that lime mortar isn't worth the time because modern bricks are too hard and don't breathe like old ones. But I've been reading that lime helps with cracking on restoration work and some new builds too. Has anyone else tried lime on a regular house and seen a difference in how the wall holds up after a few seasons?

2 comments

2 Comments

michaelrodriguez15d ago

... and honestly that foreman's missing the whole point about how the wall assembly works. I've done a few side jobs with lime on newer brick houses here in the PNW and the big difference I saw was in moisture handling. Modern bricks are vitrified, sure they're hard and don't soak up water like old soft bricks, but the mortar joint is still the weak point. Cement mortar traps moisture behind the brick face and causes spalling when it freezes, especially in a wet climate like Portland. Lime lets that moisture move out slowly instead of building up pressure. Had a neighbor's house where the cement mortar was cracking after two winters, repointed a section with lime and it's held fine through three seasons so far. The mortar itself is softer so it takes the movement instead of the brick, which is what you want.

wesley87315d ago

Ask if you've seen any difference in how lime handles the freeze-thaw cycle compared to cement in that PNW climate. I mean, I'm in a place that gets way colder than Portland and I'm wondering if the slower moisture movement actually helps prevent that spalling you mentioned, or if it just delays it. Like, is it really solving the problem or just kicking the can down the road a few more winters?