I have a garden wall that's about 10 feet long and 6 feet tall, and I've noticed some gaps where the mortar is missing, with some of them being quite deep. These gaps are located between the bricks on both sides of the wall. I'm in Texas, and I was wondering if I can just use type N mortar to fill these gaps, or if there's a better type of mortar I should consider. Thanks for any advice!
2 Answers
You could probably use type N mortar, but since it's a big wall, I'd recommend double-checking to see if those gaps might be intentional drainage holes. Just make sure they're not all over the place. It’s worth looking into the details before you start filling them in!
For durability and water resistance, I'd go with type S mortar. It's not that much more expensive and if you're fixing failing mortar, it's better to use the stronger option. I've worked on a lot of outdoor projects and my rule is: if it's outdoors, go for type S. But maybe a professional mason can give you more insights!
I'd be cautious with type S if your wall is older. Older bricks tend to be softer, and using hard mortar on them can cause issues. Common advice from restoration sources seems to suggest being gentle with historic masonry.
I checked, and they're not drainage holes. It seems like some mortar is loose and just comes off easily.