Mismatched Brick Replacement: Common Issues and How to Fix Them
Once in a while, in the life of the old historic brick building, a brick or two needs to be replaced. Sometimes damage is prolific and many bricks need to be replaced. We’ve looked at examples where a range of bricks were misfired and the damage didn’t really show up or become obvious until many years into the life of the building. Today, we’re looking at a particular example of a historic masonry facade where one particular brick had to be replaced.
Even replacing just one specific brick is tedious work because you can’t damage the adjacent bricks to remove the remainders of the old brick. Once the old brick is removed, installing a new brick isn’t that difficult. There’s particular details of the installation that have to be done right to make it look professional, but the harder part is removing the remnants of the old brick. A list of a few of the essential steps follows.
- The opening left behind after the removal of the old brick must be well cleaned.
- Before installing the new brick, the opening must be hydrated.
- Select a mortar that is compatible with the substrate and surrounding areas.
- Mortar must be applied into the opening on 5 sides.
- The brick must buttered before insertion.
- Set the brick
- Remove ooze-out
- Repoint the perimeter.
- Allow to cure
- Wash the brick face
In a separate upcoming future blog articles, we are going to talk about these steps in more detail. Today, instead, we are going to look closer at some of the main issues of mismatch:
- Brick Color
- Brick Physical characteristics
- Brick Size
- Brick Texture
- Mortar color
- Mortar texture
In the picture below, you can see this brick clearly, it jumps right out at you, visually. The color is much lighter. You cannot even detect most of the physical characteristics with a visual glance but this is a mismatch of physical characteristics, as well. The brick size is different, and you can see it. The mortar on one side is fatter and thicker. It just looks bad from a visual perspective. The mortar color also doesn’t match.
The physical differences that we discussed above referred specifically to the brick itself, but the mortar is also mismatched in physical characteristics. The physical characteristics that were referring to here are what matters the most. In some ways that is most important because even if something doesn’t officially look appealing, it will possibly still serve its functional purpose. When physical properties of mortar are mismatched, it can lead to physical failure and accelerated deterioration which can lead to destruction of the brick and surrounding bricks and even the wall and the building itself. Good mortar matching matters, critically, because without a proper match, it leads to moisture retention that can freeze in the long and bitter DC winters.
When excessive routine moisture freezes, it expands and expands with such force that it can lead to damage. As freezing water turns to ice, volumetrically, it can expand between 7 to 9%. As that ice expands it can move heavy and strong things like bricks and mortar causing them to crack and break apart. Also, even when there aren’t issues of winter freeze-thaw cycles, accelerated or excessive moisture retention can also lead to deterioration of the adjacent brick and mortar because those elements are permeable and have a slight solubility that will lead to dissolution and destruction.
The closest view follows in the next picture below. Here, it’s very clear that the texture of this more modern replacement brick is smoother. This is a machine made brick. The historic bricks were made by hand. Not only is the texture different at the surface, but the material components used are also very different. And historic times, hydraulic and heavy powerful equipment were not available because they hadn’t been invented yet. Filtering of substrate materials was all done by hand and couldn’t be done to the level of consistency expected today. That difference makes the bricks behave differently as well though.
From a physical perspective it’s all about using materials that are closest in physical characteristics to the existing. Here they took a shortcut and tried to do something cheap and generally shortcuts like that will lead to problems. You can see the thick perpend mortar joints at the sides of the brick. It looks bad.
We can Help
Our company focuses on historic restoration more than modern building upkeep, maintenance, and construction, but our company understands both types of construction very well and a full picture well-rounded approach is needed in any niche in the construction industry. Although we focus on historic restoration, repointing, tuckpointing and historic brick repair, our company also has technical knowledge and competencies in the areas of modern and contemporary construction as well as we become one of the leaders in that area of the market today. Understanding both historic and modern or contemporary construction is useful because both aspects help understand the challenges and potential solutions for challenges in building science and construction.
We can help with a variety of historic masonry restoration needs and upkeep, from modest tuckpointing and or repointing to complicated and extensive historic masonry restoration. Infinity Design Solutions is a historic restoration specialist contractor specializing in both historic masonry restoration such as tuckpointing our repointing, and brick repair. If you have questions about the architectural details or facade of your historic building in Washington DC, reach out and say hello and if we can help we’ll be glad to assist you. You can email us or call us on the telephone at the following link: contact us here.