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A Historic Brick Facade With a Multifaceted History

Here is an in-depth discussion of a historic brick facade with a complicated history

Last week, we took a look at a mid-century building facade as part of a case study to examine and understand historic masonry. This week, we’re taking a look at a  renovated rowhome in a historic neighborhood here in Washington DC.  This building is at the end of a row of homes and therefore has an exposed alley side of the building. Compared to a typical rowhome, this building has a much larger exterior facade.  Typical rowhomes have an exposed front and rear facade.  In this case there is the side brick facade which is larger than both the front and rear facades combined and it is also quite a large building.

historic brick facade side brick

Over the many decades since the original construction of this building, the facade of this building has experienced so many different modifications and changes, it is a complex assembly of different works, like a quiltwork tapestry, of different building techniques, styles, and modifications.   A short list of some of these vast and contrasting details follow:

  1. The interior wall layout has changed drastically as this building has been converted into multiple separate units.   This is common, as the density of Washington DC has increased over the years without significant increase in the height of the buildings.  Over the decades, building occupancy has increased in terms of the number of people who are dwelling or using each building, each using a drastically lower amount of square footage.   These modifications to the interior wall layout have also impacted and led to modifications to the exterior brick masonry facade.
  2. A mixture of window header types has been used in the construction of this building.   In contrast, we recently looked at similar but different building that used segmented arches for the basement level, you can read about that building as a counterpoint at the following link: Closer Look: A historic brick mid-rise facade in Washington DC
  3. As the historic brick mortar has deteriorated over the past century, multiple different repairs, such as repointing, aka tuckpointing or point-up, and even scam pointing, have been completed at different times. Some of those repairs have used vastly different mortar types, even right here in the same building, varying both in terms of color, texture and type of subcomponents in the mortar itself.
  4. A mixture of modern and historic steel and ferrous supports have been used, interspersed and embedded into the existing historic masonry facade.
  5. The building itself uses at least 4 different types of brick units.   The alley side facade of the building, where we examine most closely in this article, is mostly made with a historic common brick, but a modern type of brick has also been used at several locations at brick infills where specific window openings have been deleted (infilled) and other modifications have been made to the facade.

Large exterior facades allow for greater fenestration, the entrance of external light from the outside.   Typical rowhomes can feel a bit like a dark tunnel.  The windows are typically limited to just the front and rear facades and from there, light runs through the longer narrow length of the building.  In urban construction like this, historic brick buildings often employ an assortment of techniques to add additional exterior wall area and greater fenestration but these methods are limited in efficacy, very costly, require significant maintenance, and cause thermal impacts to the interior space.  Some examples include: lightwells, skylights, and rear ells.)  In this case, this large building facade has over 21 individual window openings, so this particular building has significant exterior light on the inside, in contrast to so many of the neighboring buildings with dark interiors.

Two distinct types of window headers have been used at the construction of this building.  At the levels above grade, a segmented arch has been used to create the window opening headers. However, at the below grade level, the window headers have been built with a jack arch.

Segmented arches are extremely common in Washington DC.  They are sort of a hybrid between a half circle Roman arch and flat style jack arch.  It’s counterintuitive, but segmented arches are not actually self supporting. They rely on internal structural framing to support the brick above. They are built so that they do apply and transfer some of the header load to the buttressing springer-like sides of the window opening, but they are not indefinitely nor independently self supporting.  (See the following article examining a corbelled butterss wall support and the following article on Roman arches for more information on this subtopic.

The picture below shows an example of a jack arch. This jack arch has been repointed with a light color mortar which stands in contrast to the adjacent older mortar to the left.

historic brick facade jack arch

In the picture below, you can see an example of a historic jack arch. This jack arch has not been pointed in the most recent years but has had some refurbishment done in decades past.  You can see mortars of different colors at and around the same area of brickwork.  The mortar at the lower area of the bricks has a light red tint, almost similar to mortar made from brick dust and lime, as was done in certain types of construction in historic times, generally a technique only used for pressed brick, not common brick as shown here.

historic brick facade jack arch window

In the picture below, you can see that there is a concave, slightly downward bent shape to the steel lintel above the window opening. Unlike modern steel angles, this lintel is just a flat bar. We’ve talked about the limitations of spanning arches built with flat bar or flat stock metal.  Metal is generally strong, but even steel is not strong enough to support masonry over long periods of time with relatively thin flat bar elements.   By comparison, structural angles are built with an “L” shape and the vertical web in a structural steel angle helps support the tensile force of vertical deflection indefinitely when properly maintained.

The next picture below shows the underside of that same flat bar, you can see that that floodboard stops short of the depth of a single brick wythe thickness and does not have a vertical return upwards similar to a steel angle.

historic brick facade brick wythe

Historic construction is generally considered to be of higher quality than modern construction. It is true that in most cases, higher levels of labor and training were used to build historic buildings, but in this case, even in historic times, they misunderstood the structural limitations of this type of steel support. In modern times, we would use stronger systems and build this type of building assembly with greater structural capacity.

In the picture below, you can see the downward concave shape of the steel support.

historic brick facade steel support concave

You can also see at the facade there are several locations where window openings have been modified, truncated or shortened and even closed in completely.   The 3 closed in openings, prominent and shown in the picture below were previously part of a stairwell. Those windows allowed light to come into the stairwell. However currently in the new interior layout the stairwell has been removed from this location and those windows have been subsequently infilled.

historic brick facade closed windows

Many decades after the original construction, supports have been installed to resist lateral deflection. In the picture below we show an example of a barnstar installed at the side facade this building.

barnstar

The all-thread that runs through the center of that barnstar is held in place with a nut and a washer and that threaded rod runs through the exterior brick, into the internal wood framing members of the building. At the Internal wood framing of the building, cross blocking is installed to support and resist lateral deflection,  Lateral deflection is the force of a large brick wall pressing outwards as it sags over time and loses its structural capacity.

In the particular picture below, you can see the corner where the front facade meets the side facade of the building.  The building front facade at the lowest level, below grade, iis clad with a split face ashlar brownstone. Upper levels of the front facade wall are built with a pressed brick. You’ll notice a much thinner mortar joint and greater consistency in the size and shape of each of the pressed bricks. Also, the pressed brick wall is built with a much flatter planar structure.

By comparison, the side facade, built with common brick and a common mortar joint, has much greater inconsistency between the Individual brick units.

common-brickThe next picture shows that difference more closely as in this look across that wall from a shallow angle.   By comparison, the parts of the wall built with the press brick are very flat and true.  Press brick was made with materials that were sifted to a higher level of consistency. Pressed bricks were fired at higher and more uniform temperatures.   As a result, press bricks have very low variation in size and shape and have a higher compressive strength.

press-brick

At one of the few locations, where pointing has not been completed at all on this building, you can see the original historic brick mortar, has shown in the photo below.

 

 

original-historic-brick-mortar

This mortar has a rough and deteriorated surface,. The texture is inconsistent and if you look closely at some spots you can see tiny stones that are mixed into the mortar.

specs-lime-in-mortar

You can also see small white specs of lime that were originally mixed into the mortar.

specs-lime-in-mortar (2)

Over the years small applications of repointing and tuckpointing have taken place at different times and have been completed by different people. You can tell that these various different types of mortar have been installed by different people because they were installed in totally different ways. In the collage of pictures below, you can see the top left picture shows sccam pointing, just a thin application of modern mortar applied on the surface of the existing deteriorated mortar joint.

bad-re-pointing-job

Even after all of these different attempts to restore the mortar over the years, there are still large areas of the building that need proper and professional pointing. We would of course recommend that all future pointing be done by a trained and competent professional who specializes in historic masonry repointing.  Modern cements should NOT be used and principles of proper pointing should be followed.

The picture below shows an area about 6′ above the adjacent grade where there are large sections of deteriorated mortar joints with recesses that will allow water to pool and enter deeper into the brick wall assembly.

deteriorated mortar joints

The collage below shows some of these areas of deterioration up close. You can see the recess of the mortar, where the mortar has deteriorated away from the face of the historic brick.

mortar-recessing

To properly maintain, repair, and care for these historic buildings, a knowledge, interest and understanding of historic building principles is required.  Here in Washington DC, historic masonry buildings are extremely expensive and the amount of financial loss caused by improper repointing and low quality construction is staggering.   However, in addition to the direct financial value of the property, there is also a cultural loss when historic buildings are damaged. By comparison, consider neighboring poor cities, when historic buildings are damaged, it’s not just the loss of value to the property owner, there’s also a loss to all inhabitants and visitors of a city, present and future, who care about architecture, history, and culture.

We encourage all of our clients, and all readers of this article and to our blog in general, to prioritize the historic built environment of Washington DC and neighborhoods such as Capitol Hill, Dupont Circle, and Georgetown and become educated on on the difference between proper historic preservation versus improper work which leads to significant damage to the historic fabric of a building.

From a conservation and preservation perspective, several approaches can be taken to improve conditions related to deteriorated historic brick masonry. Primarily, lime mortar brick joints and low temperature fired soft red clay bricks should be inspected and checked on a routine maintenance schedule, either seasonally or at least annually.   If brick masonry is kept in good condition, the life of embedded wood elements can be significantly extended.  Hire a professional contractor which specializes, understands and appreciates historic construction elements and buildings.

In this article we talked about the terminology and  concepts of historic masonry restoration, follow the links below for more related information from the IDS website:

  • Binders in mortars and concrete
  • Butter joint
  • Capillary action
  • Cementitious siding
  • Cheek wall, masonry — Draft
  • Chemical testing
  • Code, building — Draft
  • Cold joint
  • Cold weather masonry work — Draft
  • Downspout
  • Electrical distribution panel — Draft
  • Fenestration
  • Ferrous metals
  • Great Chicago Fire
  • Gutter, roof
  • Lime mortar
  • Lintel
  • Oxidation
  • Parapet coping
  • Plug, clay
  • Pressed bricks
  • Raking, of mortar joints
  • Raggle, aka reglet
  • Rectilinear
  • Roman bricks
  • Roman arches
  • Roof eave
  • Roof termination 
  • Row buildings and row homes
  • Sedimentary rock
  • Scratch coat
  • Sprung arch
  • Strike, or striking of mortar
  • Tapestry bricks
  • Tooth-in, interlocking masonry connections
  • Vitreous
  • Water diversion systems
  • Zipper-joint

These concepts are part of the fundamentals of historic masonry restoration, tuckpointing, and brick repair.

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.