Corbelled Buttress Wall Support

Corbelled-Buttress-Wall-Support.jpg-2This historic stone building is built with large span walls.   The stones used in the construction of this building are cut to a rectilinear type of shape and are therefore considered an ashlar masonry.   This wall is large and not connected with perpendicular walls on the interior of the space.  Interior perpendicular structural walls would help support the large width and large span of this wall however since it is an open space on the inside this wall is built with a single buttressing structural support on the outside.   This building was originally used for industrial manufacturing purposes over 100 years ago.  At the time, considering the use, it was better for the facility to not have interior walls adjacent to this exterior wall.  Interior walls would have been an impediment to production and functional uses of the floor space.  This buttressing plinth is used to add support, that although is strong, is otherwise too large to not have added structural support in a perpendicular position.

The added buttressing element was built after the original stone building.   From the pictures you can see that the original wall was built with stone but then the buttressing support was built with brick. That’s a sign that the two distinct elements, although currently tied together, were actually built at different times.

What Is Corbelling

Corbelling is a technique, sometimes used to add an interesting architectural detail, another times used just for functional purposes.   Here the top of the buttress was built with a corbel. That means that each successive course is recessed further back inside of the space of the masonry assembly below. You can see the top 7 courses are increasing successively recessed.  Areas of plinth bases also require upkeep and maintenance similar to exterior brick masonry walls which need periodic tuck pointing throughout their lifespan.  Restoring the mortar joints over the decades helps deter water ingress and accelerated deterioration of lime mortar joints.

From a conservation and preservation perspective, several approaches can be taken to improve conditions related to maintaining and improving structural elements of historic masonry buildings.

Terminology

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

  • Corbelled-Buttress-Wall-SupportStone building
  • Large span
  • Rectilinear
  • Ashlar masonry
  • buttressing structural support
  • Functional uses of the floor space
  • Plinth
  • Corbel
  • Accelerated deterioration
  • Lime mortar

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