Brick is some seriously durable stuff—clay bricks commonly endure for a century or longer, and there are plenty of examples of brick structures that are much older than that. If you have a brick home or a brick facade, you can expect decades of service without much worry.
But nothing lasts forever, and everything has a weakness. In the case of your brick walls, that weakness is the mortar—the cement-like “glue,” visible in the joints between the bricks, that keeps your bricks together. Mortar has a much shorter lifespan—20-30 years, on average—because it’s much more susceptible to weather, especially moisture. Over time, water seeps into the mortar and freezes, cracking the mortar with its expansion. Eventually, the mortar starts to fail, and allows moisture to penetrate behind the brick, leading to eventual failure of the entire system.
If you have a brick wall that is starting to look pretty janky, the good news is that the fix is probably pretty easy and inexpensive: You just need to repoint.
Repointing
When masons refer to “pointing,” they’re talking about the mortar laid between the bricks. “Repointing” is just what it sounds like: removing damaged mortar and putting in fresh mortar to replace it. The process is pretty straightforward, and can be a pretty easy DIY project if you’ve ever worked with masonry tools before.
Determine the type of mortar you need. Modern mortars use portland cement, resulting in an extremely hard cure. That’s fine for modern bricks, which are similarly hard. But older bricks are softer and require a softer mortar that “gives” a little. You can make a good guess using the age of your home—if it’s 50 years old or less, you can go with a standard modern mortar for your repointing project. If it’s older than that you might need to do some research or consult a real mason.
Scrape out the old mortar. Using a cold chisel, a grout saw, or a joint raker, remove a layer of the old mortar. You should remove about twice the width of the vertical brick joint, typically about half an inch. You don’t want to remove too much or you can undermine the structural integrity of the brick.
Push in fresh mortar. Now you refill the joints with fresh mortar and tool it until it’s tamped in well and fills all the voids. Finish the exposed face of the fresh mortar so it looks good.
That’s it—while it takes some patience and a little skill, it’s not a difficult job. Note that you might also hear the term “tuckpointing,” which is a similar process—in fact, the term is often used interchangeably with “repointing,” although they are slightly different. Tuckpointing involves using two mortars of different colors to achieve an aesthetic effect. If all you’re worried about is maintaining your brick, you probably don’t need to worry about tuckpointing.
When to repoint
Even though repointing is relatively easy and inexpensive, you still don’t want to go through the trouble unless you have to. Here are some basic ways to tell if your brick needs to be repointed:
Age. If your brick is a few decades old, it very likely needs repointing—or an inspection, at the very least.
Crumbling mortar. Look at the mortar joints. Have they eroded noticeably (more than a quarter inch)? Are they crumbling into a dry, sandy mess? They need to be scraped out and repointed.
Cracks. If you can see noticeable cracking in the mortar and the brick, it indicates moisture penetration, so repairing the mortar is likely necessary.
Gaps. Can you see spots where the mortar has totally separated from the brick? If so, it needs repairing.
If you’re uncertain, you can perform a quick test: Take a knife or similar tool and scrape the mortar joints. If you can easily remove some of the mortar, it needs repointing, even if it looks superficially okay.