There are several different types of masonry bonds. Some of the most prolific ones are the running bond and the common bond. In DC we will also often see other types of masonry bonds such as the Flemish bond and once in a while we’ll see the English bond as well.
One type that is used more often in modern masonry is called a square bond. All of the other types of bonds have variation between the prepend joints. Here too, with a square bond, the bed joints will run uninterrupted. Normally in one course of bricks, the prepend joints will not line up with the course above and below. In the square bond however the prepend joints lineup all the way up-and-down.
Yet at a glance, you can see that the building in the picture below is a more modern building, not a classic historic building.
When you look even closer at the layout of the masonry units you can see that the vertical perpend joints actually run in line with one another from course to course.
If you don’t happen to notice that from a distance, when you get much closer it’s very obvious that the joints all lineup in an uninterrupted rectilinear grid.
Just for demonstration, in the image below, a black lines have been placed on top of the brick joints and here you can see that square grid-like pattern of the brick joints. This is indicative of a square bond. Even though the masonry units themselves are a rectangular shape it’s still called a square bond because essentially, all joints lineup in a 4 way square pattern.
Each different type of brickbond has different characteristics. Characteristics. This type of bond is actually one of the weakest but in this case, with modern construction, the buildings often do not rely on the brick facade for structural strength. In fact in this case the wall behind the brick is the structural wall and carries the load path. In fact, in this unique circumstance the brick at this building works more as an aesthetic element and as as a weather screen from the exterior elements. By comparison, even a weak bond, like the running bond is stronger because the running bond has an overlap of brick halves, even though just within each individual wythe of the wall. This type of facade construction, is different than historic construction, yet still good to understand, even as a counterpoint to historic masonry restoration. In time buildings like this will, as well, need repair and even brick joint restoration and tuck pointing. This building masonry work was built with a modern portland type mortar instead of a higher content lime mortar. Therefore, compared to traditional historic masonry a building like this is decades newer and can be expected to not need wholesale pointing and tuckpoint restoration for decades to come.
In this article we talked about the following terminology and concepts, click the links below for more related information from the IDS website:
- Brick bonds
- Running bong
- Common bond
- Flemish bond
- English bond
- Square bong
- Perpend joints
- Bed joints
- Load path
- Aesthetic element
- Weather Exterior
- Exterior elements
These concepts are part of the fundamentals of modern and historic masonry building construction, repair and restoration.
The links in the list above will take you to other articles with more information on defects, failures, preservation and repair of historic masonry. You can learn a lot more on our blog. Feel free to check it out. If you have questions about the historic masonry of your building in Washington DC, fill out the webform below and drop us a line. We will be in touch if we can help.