In the spirit of honesty I will admit up front that I cannot precisely nail down the origin of this idiom. [Sigh of disappointment] The earliest attestations I can find are from late 19th century publications, but the idea, and maybe even the exact phase, are almost certainly older. The saying is, at its core, a reminder that inanimate, lifeless things can communicate experiences even without the gift of language – something that alternately delights, puzzles, and frightens us. When someone says, “If these walls could talk,” it is never in reference to the mundane or unremarkable. The element of the unknown, a reality we can’t see, tantalizes us.
Walls the world over tell tales. The dressed stone walls of late medieval castles pocked by cannon-shot bespeak the end of heavy stone as useful fortification. The Greek Revival architecture of the late 18th and early 19th century reflects the renewed interest in democracy by the great minds of the Enlightenment. This is, of course, why so many buildings in Washington DC are styled this way. Molten glass and charred wood tell the tale of fire, and the built-up layers of yearly repainting in college dorm rooms… well, never mind. Forget I mentioned that.
Walls do speak; and if you know how to read them, you can put together a plausible picture of what has befallen them.
The exact subject varies from inspection to inspection, but I often get asked what to look for in a given system or feature of a house. How do you figure out the age of the HVAC system? How do you reckon roof replacement? What brands of appliances are only adequate and which perennially perform with precision?
The short answer is that it takes experience and study to make confident claims about any of these things. Still, with a little knowledge and strong observational skills, even a novice can uncover the something of a house’s history. This post focuses on walls, specifically brick walls. Winchester and the Shenandoah Valley are bedecked with brick-clad homes, new and old. And while the ultimate judge of whether or not a wall is sound must be that of a structural engineer, my aim is to put readers in a position to ask smart questions, make shrewd perceptions, and, of course, well-informed decisions.
Structural Brick vs. Brick Veneer
When assessing exterior brick, first determine if it is structural or not. “What?” you say. “Brick isn’t always structural?” I know. The third of the Three Little Pigs also taught me at an early age that brick is structural and reigns supreme over wood and, well, straw construction. However, much of the brick seen on houses, especially those built after World War II, is a veneer. As with wood veneer on furniture, brick veneer is intended to have a pleasing aesthetic quality, but, like all external surfaces, it also serves to protect the structural elements behind it. In a house with a brick (or stone) veneer, it is the wood framing behind the exterior masonry that holds up the roof and shares in the support of the floor joists.
As in the illustrations below, brick veneer can usually be identified by the absence of header courses. In header courses you see the short end of the brick because it is turned perpendicular. This arrangement adds more lateral stability than simple parallel construction. It is less common, but structural brick walls can be held together with metal ties as well. These are harder to identify as structural. A fantastic illustration of how wall brick of different depths (wythes in masonry terms) are held together can be found here.
Why is this distinction important? Well, with load-bearing brick any sort of damage necessarily carries some structural implications. This may be, but is not necessarily, the case with a veneer. Think of it this way: A worn dust jacket may be the sign of a book in need of a bifocaled librarian and miles of book tape, but it could also just be the sign of a valued volume that is otherwise unscathed. Cracks, cavities, and crevices in structural brick are usually deserving of more immediate attention and come with a higher price tag for repairs.
Specific Kinds of Damage:
Bowing Brick: Be ye very wary. When a masonry wall is bowing or leaning it means that a tremendous amount of force is being exerted unevenly on it. A leaning masonry wall is generally the result of pressure at the top or bottom. The top is the more frequent of the two. A bowing or bulging wall, on the other hand, is indicative of a concentrated force in the middle.
Why are these sorts of deformities disturbing? The answer is that load being walls work in plane: they are very strong vertically, but far less so horizontally. If the continuity of the vertical plane is disturbed, the bearing strength is compromised. Two results are possible. Either the load is transferred to other planes not designed for the extra weight (adjacent walls) or failure occurs. A bit of – you played with building blocks as a kid so you know intuitively this is bad – skepticism is not a bad thing if you see these conditions.
Trapped Moisture: This condition is not exclusive to brick veneer, but more prominent in this style wall than with structural masonry. When water gets trapped behind a masonry veneer and can’t evaporate it poses potential damage to the wood framing and interior finish of the house. Yes. House wrap is designed, in part, to keep moisture out. This assumes, however, that it is perfectly sealed and the amount of moisture present is below the anticipated level. Trapped moisture can be a tricky condition because it can go unnoticed for years before making its devastating debut as crumbling drywall or a maelstrom of mold. To avoid aggravations such as these, builders usually leave small holes, called weep-holes, in the mortar to allow air to circulate behind the veneer. Some building firms do not appear to be sold on this practice, but more often I see that homeowners, unaware the small holes in the exterior wall of their house are intentional, have plugged these.
If I suspect that water is getting trapped behind a masonry veneer, I’ll use a moisture meter to see if the area in question has a higher moisture content than other adjacent walls.
Lamentable Lintels: Whether the brick you see is structural or not. Masonry walls need a way to transfer the weight of the brick (or stone) above openings for windows and doors. This is done with either an arch (thanks, Romans!) or a steel lintel.
Telltale signs indicate when the support over a door or window is failing. If the mortar between the bricks above forms a triangle above an opening, the lintel or arch has moved.
This is not a catastrophic issue if promptly addressed by a qualified mason. The more frequent phenomenon I encounter involves rusty steel lintels. Steel, when exposed to the elements, will rust and expand like freezing water. This can actually dislodge the mortar at the upper corners of a door or window. Once the mortar is gone, water has a foothold and starts to chip away at the masonry. Sometimes neglect is responsible for this sort of damage, but I also see a lot of steel that is only primed and not painted. Primed steel usually has a dull reddish color and will not hold up to the elements for long. If left unaddressed, the damage from rusty steel lintels can sprout diagonal cracks that run all the way to the edge of a wall. Houses built between World War II and the 1980s are where I see this condition the most.
Scraping the lintel to remove the rust, repainting, and finally repairing the mortar are the steps professionals take to alleviate this ailment.
The Mystery of the Missing Mortar! Too often, people see masonry as everlasting. In the traditional telling, the first two little pigs become bacon for the wolf. Disney amended this and the less thoughtful, industrious relatives end up cohabitating with the pig who built his house out of brick. An even more modern retelling would probably also have the two dispossessed pigs piggybacking on the third’s cell phone plan
But while it is true that masonry is generally more weather resistant than wood, plastic, or even steel, this does not mean that it never needs repairs. At some point, the mortar between the brick or stone on your house will crumble away and it will be time to have a mason repoint between the individual pieces. This is not so much a process that adds strength to a wall as much as it a reaction to masonry’s eternal enemy, water.
If, in looking at a brick or stone wall (veneer or not), you notice that the mortar has begun to crumble or is breaking off in sections, it is probably time for repointing. This post is about walls, but you’ve probably noticed that the mortar between the bricks of porches and steps deteriorates more quickly than when vertically oriented. This, again, is the work of water, always wearing away the mortar.
Just Another Brick in the Wall: This is not the sum of the conditions I look for when reviewing the condition of brick and stone walls. I’ll save damp rise and keeping veneers 6-8” above grade for another post. But looking for these conditions will make you a better buyer. Finally, as with other projects that may involve structural elements, my encouragement is for folks to do their homework and get a number of quotes from credible contractors rather than risk repairs themselves.
 Cf: ‘If these walls could speak, what tales they might tell us!’ is the common expression of the visitor to any ancient edifice of habitation renowned for its historic or domestic interest. – W.W. Fenn, Speaking Walls, 1875.
“If these walls could speak,” I said, “they would be able to tell strange stories.” – B.L. Farjeon, A Secret Inheritance, 1886.
 Some buildings from the 19th and early 20th century use a brick veneer over structural brick. The unseen structural brick is less uniform neatly mortared.
 Weep-holes are often stuffed with rope or a plastic mesh to keep dirt and insects out.
 Please forgive the bad pun.