Jerry Painter
A few days ago, I stopped for lunch at a restaurant that we have been patronizing for over 50 years. We had been told for several months that it was going to be remodeled, and an addition would be added. Lo and behold, they finally started. Over the next few days I watched as the ground was cleared, the addition laid out, and the concrete footings were poured.
A few days later, the three course CMU foundation was laid. One of my long-term problems is that I see too much. The next time by I stopped by, two young workers were putting the masonry sand in the building area. I saw four OSHA violations and two building code violations. Let’s just say that they were not aware of the culture of correctness in their company, if there even is one.
I was out of town for a few days and upon my return I found that the walls were up and the building dried in. Staying in the parking lot and not trespassing on an unstated building site, I was looking at the masonry walls.
Yes, a lot of people think I’m crazy because I look at masonry all the time. But I’ve been familiar with this masonry world since my first memories. What I saw reminded me of a very important aspect of masonry work.
One of the last things we do to our masonry wall, no matter the material, is to “tool” the joints. By my definition, the tooling of mortar joints is simply putting a finish treatment on the joints with a tool to give the joint a desired profile. There are many profiles that can be supplied with a particular tool application, and you can find details and description on the BIA and NCMA websites.
The building the addition is being added to was built 51 years ago. A lot, if not most, exposed CMU buildings had a finish we called a “float and V.” This was simply floating/rubbing the head joint smooth and putting a V joint into the bed joint.
Once painted correctly, the wall had only horizontal lines across the finish face. The “float and V” could only be used if the masonry wall was painted. This was a great look back when masons would lay the units plumb, level, and a consistent distant from the line.
The problem with this project I am watching is the masonry did not meet all three of those requirements. Right at eye level from the parking lot was a bed joint larger than the rest. While this is not the best practice, it is not unusual. This typically happens when the masons have pulled a tight/taut line from corner to corner to lay the units to.
As they add course, the line begins to sag ever so slightly, and the longer the wall the more sag there will be. This is why masons use a line “trig/twig” to lift the line and take out the sag. When they return to continue the wall after the scaffolding has been placed, they will put the line back in place and pull it tight/taut again.
The bed joint will be wider where the sag was the greatest- typically the center of the wall. While this is not the best situation, and unless the bed joint is larger than is allowed by the project specifications or code (TMS 602), you can still work with it. The key is the tooling.
The first reason for good tooling is to give the masonry the correct joint treatment specified or requested. There is no standard for tooling, and the building code only says to “tool the joints round unless otherwise specified.” The most important reason to properly tool is that the compression used to apply the tool forces the mortar to the edges of the masonry unit, and creates a better seal/bond to the unit.
The compression part of the tooling is equally important as it seals the face of the joint. This compression applied at the tooling causes the masonry to be more water-resistant. The correct tooling of the masonry joints can also improve the look/aesthetics of the wall.
With CMU a sled or long striking tool should always be used. This tool (used properly) can cause the joint to appear straight and equal in size. A hand jointer or short jointer will allow the tool to wiggle the variations in the CMU and joint.
A lot of folks don’t understand the tooling of the joints or don’t care. This is an issue of ignorance or attitude— both of which should be corrected by whatever means necessary. Proper tooling can improve the look of mediocre masonry or make a mess of great work, and is the final showing of skill and pride of the mason. FINISH STRONG.
Until next time RAISE THE LINE and come on around the corner.