Identifying and Addressing Collapsing Brick Headers
In the past two week’s blogs, we looked at two different types of issues related to header failure, associated with lateral deflection and differential settlement. Particularly, last week, we looked at a sheared stone header split into three parts.
Today we’re going to look at examples of failures which lead directly to actual collapsing where the walls (and building) actually fall apart. The pictures below are the perfect example of the nascent stages of that process. Here, you can see the stair step cracking in the shape of a perfectly centered triangular failure that follows the corbelled support of each of the bricks above that header separated by the area of failure of the header itself below.
There might be a little bit difficult to see in the picture above, but when you look more closely in the next picture below, you can see that there are issues of both stair step cracking, sagging, and undulation which is like a waviness in the otherwise intended flatness of the wall itself.
These issues, are all concentrated around the area of the window openings. These openings, that apply both to doors and windows or any type of fenestration or ventilation, are needed for the building to really work properly, yet you can see this concentration of these problems at these locations indicates that the support to allow the openings to be installed in the field of the brick otherwise where brick would be continuous, requires particular attention and ongoing upkeep throughout the years.
The issue appears to be specific to these openings and it’s definitely happening coincidentally at those areas of the openings, but it also is impacted by the same type of deterioration and mortar failure we see at other parts of the building as well.
As the building ages. It’s exposed to continuous ongoing cycles of moisture. These periods of moisture happen with precipitation cycles but also happen throughout the year as temperatures change, even on daily cycles. The air itself has moisture which will cause condensation to occur at several parts of the building where the building itself, as a large thermal body, works like a heatsink and can retain lower temperatures than the ambient air which can naturally lead to condensation.
When you look really closely in the next picture below, you start to get a sense for the lateral deflection that we mentioned previously in the last week’s blog. Lateral deflection is when a building wall begins to have a bit of a non planar or non-flat type of shape. In simple terms, it is when the walls begin to belly outward a bit.
This often happens in historic masonry walls when they exceed typical or needed ranges of repointing or tuck pointing. Repointing historic masonry mortar joints is very important because these joints deteriorate before the remainder of the historic masonry.
In other words, the bricks themselves are intended to be harder and last longer than the mortar. It’s important that the bricks are actually harder than the mortar because as the buildings have typical micro movements through things like expansion with daily temperature cycles, the mortar could actually damage the brick if the mortar was harder. This particular issue of hard mortar is a big problem with less experienced restoration contractors because they normally use the wrong type of mortar.
I took a picture below with a little bit of sun in the foreground, but this particular building had a failure and collapse a few years back. As the window header deteriorated, all of the brick in the triangle shape above ended up collapsing and had to be rebuilt. Some of the salvaged brick may have been reused, but you can clearly see that it does not match perfectly.
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 tuck-pointing and or re pointing to complicated and extensive historic masonry restoration. Infinity Design Solutions is a historic restoration specialist contractor specializing in both historic masonry restoration such as tuck pointing 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.
