Training — It’s Absolutely Critical
Dennis Rude
There is no question that Jahn mortars and grouts are the best products on the market for long-lasting historic masonry restoration and masonry repairs of any kind. Those in the know—architects, restoration specialists, and other specifiers—will often insist on Jahn and only Jahn products. Some of the world’s most significant structures—from monuments and sculptures to historic skyscrapers and national landmarks—have been repaired and restored using Jahn Mortars. Why? Because, installed properly, Jahn Mortar will last as long as the original stone. Jahn Mortars are engineered to each masonry type and they are fully compatible with that type. Jahn M70 Limestone is completely compatible with limestone; Jahn M70 Brownstone is completely compatible with brownstone, and so on.
But these mortars are not magic. In fact, in the wrong hands, they’ll be as effective as any other mortar on the market. What’s different about Jahn? Bonding agents—Jahn Mortars do not contain bonding agents. Jahn Mortars require craftsmanship to install; other mortars (mortars with bonding agents) do not.
The introduction of bonding agents was supposed to be a great technological leap forward in our trade. Bonding agents are like glue, and mortar mixed with a bonding agent will in fact stick to anything. It makes almost any would-be mason look like an efficient and technically skilled craftsperson. But there’s a high cost to this “easy” path: bonding agents are not compatible with masonry. Bonding agents impede the natural characteristics of masonry—especially how masonry allows for the migration of moisture and salt. It’s very common for repairs using a bonding agent mortar to fail in five years or less.
Bonding agents cause another, and maybe even a more significant, problem. For thousands of years, masons had to know what they were doing—had to know the techniques and develop their craft in order to create beautiful and lasting results. Today—and for the last few decades, really—it’s been technology, rather than technique, that masons have relied on. What that means is, if I put a bucket of Jahn mortar into the hands of an average mason working today, they wouldn’t know how to properly apply it.
Many of you already know the story of how we started Jahn training. I’d discovered these incredible materials and championed them in the US, only to find that, despite the quality of Jahn Mortars, I was getting complaints when repairs failed. I was flying all over the country to investigate these failures, and they were always the result of improper application. I knew then that I was going to have to offer training.
Our first training class ran in 1984. It was voluntary. I had just two students, both from the same company. This was not a good sign. I was faced with a decision: either ask for masons to get training or require that masons get training. I went the required route.
This decision was met with indignant responses, but, in the end, most got onboard—and the restorations and repairs got better and better. It didn’t take very long for these classes to really take off. The masons appreciated learning how to use technique rather than glue to make their work stick, but it was the engineers and the architects who really helped our training program grow. Now training is fairly common all around the industry, and I take some pride in that because we really kicked it off for everyone.
After more than 35 years, I couldn’t even estimate how many people have been through training at our shop in Hanover, Maryland, at the Green-Wood Cemetery in Brooklyn, New York, and at job sites all over. Wherever we train, we always start with simple patches. Whether it’s a big or a small repair, the key is mixing the mortar properly for various surfaces and situations. Jahn Mortars are used in a drier mix than most masons imagine. The mortar starts out drier, and it dries quickly in the pail, so we are constantly preaching “re-temper the mortar, re-temper the mortar.” That’s the key to making it stick. We teach them how long to wait before they finish a repair to make it have the texture and color they want—fairly simple stuff.
The second day gets more complicated, with overhangs and heavy, thick and deep repairs. We train them to get the job done right, and to do it quickly—time is money! A few years ago, we dropped the required third day, which focused on marble patching, grouting, and ornamental carving, but I’m thinking of bringing that back.
[EDIT: As of April 2024, all Jahn Certification Courses will return to 3-Days.]
In the classes we hold in Hanover, Maryland, we can go deeper into color matching and how we develop our mixes to match certain building facades and we get the benefit of touring our color lab and R&D lab, but I think the best trainings are those at the job site itself. The masons don’t lose any time that way, and we work together on the actual surfaces they are repairing. We can address situations they might not know how to fix on the spot—saving them trial-and-error time. These job-site trainings have become extremely popular.
We aren’t done innovating our training programs either. As I write this, we are developing a recertification course. In some cases, it’s been decades since we’ve trained a particular mason. So it is high time we offered a refresher course. I’m excited about it because we are going to be re-certifying people on some old-school skills and techniques, but we are doing it online.
I guess technology in masonry repair isn’t all bad.
