Appreciation post: That red brick from the 1940s is way softer than you think

I was working on a repointing job last month on an old house built in 1948. The owner wanted me to match the original mortar, so I started doing some research. I found out that bricks made before the 1950s are often fired at lower temperatures and have a higher absorption rate. One source I found from the National Brick Research Center said old red bricks can absorb up to 20% of their weight in water. That blew my mind because modern bricks are usually under 10%. I had to switch to a lime-based mortar so the brick wouldn't crack under pressure. Has anyone else run into this problem with older homes? What mortar mix did you end up using?

2 comments

2 Comments

jake_dixon3d ago

That moisture factor changes EVERYTHING about how you approach the repair work.

river3511d ago

Yeah @jake_dixon nailed it with the moisture thing. Buddy of mine tried to patch a deck in August without checking for dampness and the whole thing peeled off in two weeks.