What Is Confined Masonry?

confined masonryFor instance, during one Chilean earthquake, only 16% of confined masonry houses partially collapsed, as opposed to the 57% of unreinforced brick masonry buildings. So, the following is not an exaggeration: confined masonry has the power to save lives.

Confined masonry

Fundamentally, masonry construction has remained the same for thousands of years. But historical events (and, in this case, natural disasters) have changed the course of the craft before. One of those documented game-changers was the Messina earthquake in 1908.

The Messina earthquake struck southern Italy with a magnitude of 7.1. The strength of the impact was enough to level every URM (unreinforced masonry) building across Messina and Reggio Calabria, and claim almost 200,000 lives. Basically, it called for some serious rethinking on the part of masons.

And rethink and reconsider they did. Out of that global brainstorming session came the concept of confined masonry.

What’s the big deal about this type of masonry anyway?

Before confined masonry, there were only two options for erecting low to medium-rise buildings: unreinforced brick, or a non-ductile reinforced concrete frame. Both performed abysmally in seismically active zones, in which collapse was almost an inevitability.

Confined masonry also required a reinforced concrete frame, but because of the robust construction associated with this construction type, seismic resistance became attainable.

For instance, during one Chilean earthquake, only 16% of confined masonry houses partially collapsed, as opposed to the 57% of unreinforced brick masonry buildings. So, the following is not an exaggeration: confined masonry has the power to save lives.

How is confined masonry constructed?

With a regular, infilled RC (reinforced concrete) frame, a worker pours concrete first and then lays the brick walls afterward. With confined masonry, engineers simply reverse this process. Masons erect the brick first, and then fill the supports with concrete.

The result of this method? The brick walls behave the same as concrete under lateral seismic loads, as opposed to the infill panels in a standard RC frame, which turn into compressive diagonal struts. To put this in laymen’s terms: forces work together, rather than against each other.

What are the chief benefits of confined masonry construction?

The concrete frame in confined masonry consists of two types of confining members. Vertical members are called tie-columns and are much smaller than in a typical RC frame. Horizontal members are called tie-beams. Though neither are columns or beams in the strictest sense, the name seems to have stuck due to their placement.

Here are a few advantages to this construction style:

  1. Reduces the brittleness of masonry walls under earthquake loads and thus improving seismic performance
  2. Elevates the in-plane and out-of-plane stability of thin structural walls
  3. Enhances the straight, ductility, and energy dissipation capacity of the entire structure

Why don’t more buildings use this method of construction?

Nowadays, brick-and-mortar masonry is less common. In fact, most modern buildings that feature brick are supported via timber and concrete and are structurally independent. Brick and natural stone is applied as a veneer, and so, earthquakes are less of a problem to begin with.

Even so, confined masonry is popular in South and Central America, Asia, and Eastern Europe. Well, if you want to see this style of masonry in action, it’s likely only an airplane flight away!

Specializing in extensive masonry repair and rejuvenation, Cirigliano Masonry serves home and business owners throughout the Pittsburgh area. From design to build, as well as complete restoration options, rely on us for Stone Masonrypointing and repair. We also offer general masonrystone repair, and more.  

The History of Masonry: A Brief Overview

A domed structure against a blue sky.

Masonry has been around since the early days of human civilization, making it one of the oldest skilled trades.

On the surface, that may seem like incredible job security. But before you go off to reconsider your profession of choice, think about how an artistic craft like masonry continues to find relevance in a world full of smartphones and 3D printers.

Have you come up with a guess? Well, if you chose constant reinvention, you’re in the right ballpark. As Steve Jobs once said: “If you don’t cannibalize yourself, someone else will.” While the unpleasant imagery is a little hard to swallow, what he said is essentially applicable: masonry has lasted 6,000 years because the definition of masonry changed dramatically with each forward leap. And masons were not afraid to outdo each other every step of the way.

So, let’s go over some of those monumental steps in the history of masonry. Obviously, it’s difficult to encompass six millennia in a single blog, but we’ll settle for slightly less.

At first there was…mud. And rocks. Lots of rocks.

Art and mechanical science are often imitations of nature, and masonry was no exception. Early man observed natural caves and, realizing how rare they were, sought to emulate their impervious shelter. Thus, the earliest attempts at masonry were born.

Some of the earliest attempts by these fledgling masons have been found in Aran Islands, Ireland. They were circular stone huts, partially buried, that lacked the mortar and brick we associate with masonry construction today.

Later on, people across various geographic regions began to form bricks from pieces of caked mud. These were often sun-dried, meaning they took a long time to produce, and lacked the structural integrity of natural stone. Wet mud was utilized as a mortar to form watertight seals.

Giza Pyramids.

Then the Egyptians came around.

The Great Pyramids. The Sphinx. These amazing structures are still standing today, due to the elaborate stone craft of the ancient Egyptians. But all was not as picture perfect as most people believe: the ancient workers used a weak mortar of pure lime and sand (prone to crumbling), built their structures on weak foundations, and struggled to transport the massive blocks of limestone, sandstone, and granite.

Yet, their contributions and fine craftsmanship helped masonry become a palpable force to be reckoned with. Despite the shortcomings of their construction style, the sheer weight of the natural stone they used kept their structures upright – even as civilizations fell apart.

Roman arch.

In time, the Romans invented concrete.

We know what you might be thinking: “Who cares?” Well, concrete provided great freedom in shaping bricks and, in turn, structures.

Stone lacked a thing called tensile strength. This meant that the stone would break under its own weight when supported by piers and walls (which explains why people would, instead, lay natural stone on top of each other).

Concrete did not have this problem, and as a result, the Romans were able to build huge arched bridges and aqueducts in vast numbers.

Cathedral.

The Middle Ages were far from middle-of-the-road.

Religion was the predominant motivator for masonic construction across the European and Islamic world. As such, builders aspired to the heavens with pointed vaults, flying buttresses, and soaring spires.

By this time, most masons had solved the problem of tensile strength by using compression. Cathedrals, mosques, and fortresses were erected in stone, eschewing the famous concrete arches of Romanesque architecture for Gothic stylings.

Michigan Central Station.

The Industrial Revolution revolutionized brick masonry.

With the advent of mechanical engineering and industrial machinery, brick and stone materials could now be transported at a rapid rate. But masonry had fallen out of fashion in the decades prior, and whole cities (such as Chicago) were assembled from wood. This later proved disastrous for them.

The invention of Portland Cement (a mixture of limestone and shale) in 1824 helped revitalize masonry construction. The new formula allowed concrete to dry in wet conditions and overcome chemical attack.

In the 1920s, the cavity wall, a dual wall of brick or concrete separated by a hollow space in the middle, saw widespread use. This pioneering technique allowed water to drain through weep holes, preventing dry rot and premature weathering.

Modern masonry preserves tradition.

Nowadays, the art of masonry is alive and well. While masonic structures have largely been supplanted for high-rise buildings of concrete, wood, and steel, many homeowners still find value in stone and brick laying.

We don’t blame them! Masonic structures continue to be preserved and cherished by community members and cultural organizations alike.

Specializing in extensive masonry repair and rejuvenation, Cirigliano Masonry serves home and business owners throughout the Pittsburgh area. From design to build, as well as complete restoration options, rely on us for brick masonrypointing and repair. We also offer general masonry, stone repair, and more.

Designing with Masonry

Whether you’ve made the decision to add a natural stone veneer to a preexisting structure, or you’re looking to build something from the ground up, masonry can give your home a classic appearance. But masonry isn’t always clear-cut – brick-and-mortar constructed from concrete or clay can evoke everything from the architectural wonder of the Colosseum, to the dour plainness of a New York City tenement building. Suffice it to say that design is just as important as the material used.

Cottage made of stone. Photo by David Castor

Make masonry an integral part of your property’s design.

Whether you’ve made the decision to add a natural stone veneer to a preexisting structure, or you’re looking to build something from the ground up, masonry can give your home a classic appearance. But masonry isn’t always clear-cut – brick-and-mortar constructed from concrete or clay can evoke everything from the architectural wonder of the Colosseum, to the dour plainness of a New York City tenement building. Suffice it to say that design is just as important as the material used.

So, how can you take advantage of the low-maintenance, fire-resistant properties of masonry while enhancing the look of your home? Read on to discover what you need to consider before throwing your hat into the ring.

I love the look of masonry…but I already have a stick-frame house.

Not a problem! Adding natural or artificial stone to your home’s exterior is a great way to raise property value while accentuating your favorite aspects of a home’s design. You’ll also get the added benefit of durability in the face of oscillation (a force that appears during an earthquake or extreme winds), which is the “Achilles heel” of masonry architecture.

Brick or stone veneers can be applied to concrete blocks, poured concrete, and other unsealed, preinstalled masonry. If you have a wood surface, you’ll need to nail double D paper to the wood to create a vapor barrier. After preparing the wall, mortar can be applied. Even if you’re an avid DIY-er, we recommend having professionals (like Cirigliano Natural Stone & Masonry) perform the installation, since masonry is more of an art than an exact science.

A few great places to apply veneers are:

  • Columns
  • Pillars
  • Front driveways
  • Below and around window panes
  • First-floor siding

How else can I incorporate masonry design into my home?

  1. Try stone walls instead of white picket fences.

 Building with natural stone means that no two stones are alike. So, if you want to break out of the cookie-cutter format of tract housing, start with a visually complex façade in the front of your home.

Natural stone walls are where rustic elegance meets modern chic. Couple them with a fountain or garden, and you’ll be stunning your neighbors in no time.

  1. Why not add a stone or brick walkway to match those walls?

Wood walkways look great and all, but with the amount of maintenance you’d go through to keep that finish and sealer intact in rain, sleet, and snow, you might as well outfit your front porch in stone. Masonry is known for standing up to inclement weather (think about how many ancient structures are still standing today), and isn’t subject to cracking like a standard, poured-concrete pathway.

First impressions count, and if there’s even the faintest possibility that you may sell your home or property one day, a stone walkway is an attention grabber. You may not judge a book by its cover, so to speak; but you can bet potential homebuyers will write-off purchasing a property just by its curbside appeal.

  1. Chimneys and fireplaces look better with mortar.

You may already have this checked off on your itinerary; for a large percentage of homes built in the latter half of the twentieth century, this is the only part of the house that features brick or stone constituents. Yet, many contemporary homes are eschewing tradition in favor of mantels and cladding of solid marble, wood, and artificial stone.

Whatever material your fireplace has currently, upgrading the buildout will give your living or dining room a little bit of that pastoral élan which older cottages have. It’s also an excellent way to accentuate the colors of your mantel and hearth.

  1. Patios and masonry go together like peas in a pod.

Entertaining guests? Or maybe you just want to spend a relaxing time outdoors with the whole family? Paver stones, made of a cement-based aggregate, can add a European sophistication to an afternoon barbeque. They’re easy to clean with a hose and make a natural gathering place for adults when children play on the grass of your backyard.

Specializing in extensive masonry repair and rejuvenation, Cirigliano Masonry serves home and business owners throughout the Pittsburgh area. From design to build, as well as complete restoration options, rely on us for brick masonrypointing and repair. We also offer general masonry, stone repair, and more.  

What is Masonry Restoration?

Learn about the value behind masonry restorative services.

It’s no secret that masonry has existed for close to 6,000 years. And while the process has become more uniform and less common, for many, the aesthetic of layered brick or stone has no equal.

Buildings constructed with brick and mortar serve as historical artifacts and markers of the past, reminding passing pedestrians and frequenters of these older buildings of America’s rich cultural history. But despite the durability of masonry construction, these structures can eventually look a little worse for wear, especially after a hundred years (or more) of constant use.

Masonry restoration is the art of bringing a masonry structure back to its original form or improving upon the original construction. A variety of different methods can be utilized to reinvigorate an older property, and they’re often used in tandem to produce a desirable appearance.

Do I Really Need to Restore the Masonry of My Building?

If your commercial or residential property is maintained well, and occasionally repointed (a fancy way of referring to the process of repairing joints with mortar or cement), then you’ll likely never need to restore your masonry.

However, many antiquated structures without reinforcing material, such as rebar or concrete, may require retrofitting – even if they appear structurally sound from the exterior. These masonry buildings are called Unreinforced Masonry Buildings, or UMBs, and they run the risk of toppling over in areas where earthquakes occur frequently.

Think you’re in the clear because you only have a brick or stone veneer on the outside of you building? Think again. Mortar may need to be repaired between bricks or units, since veneers are more prone to water damage and leaking.

The Most Common Types of Restoration Practices:

  1. Tuckpointing Can Leave a Façade with the Look of Perfection.

Tuckpointing is the act of using two contrasting colors of mortar in the joints of brickwork, one color matching the brick itself to give the appearance that fine joints have been made. Often the old mortar is routed or ground out, and replaced.

The definition of this method is often conflated with repointing (to fill in or repair joints on brickwork that are damaged, cracked or crumbled in older masonry), but make no mistake – tuckpointing is largely completed for visual symmetry. The two often go hand-in-hand during restoration however, which may explain the confusion.

Brick Wall

  1. Repointing Is the Meat-and-Potatoes of Any Restoration.

The process of repointing starts with a mechanical angle grinder, which is used to removed damaged mortar between horizontal joints. Any remainders can be scraped out with several different devices. Then they are filled in with new mortar which matches the pre-existing mortar’s type.

Maintaining functioning mortar joints in a masonry building is crucial to avoiding structural collapse under stress. But the most common reason for repointing is to prevent water penetration through de-bonded, cracked, or deteriorated mortar joints.

A brick wall will last around 100 years without needing repairs, but the mortar joints will likely hold their own for only twenty to thirty years. If they’re crumbling, cracked, or leaking, it’s probably time to get some repointing done.

Scaffolding and Brick Facade

  1. Brick Replacement Keeps Structures Sound.

This might not be an easy choice for building owners who are purists and wish to preserve a certain look or material. After all, newer brick has more compressive strength and is less permeable to moisture. Salvaged and historical bricks are available; however, they are seldom recommended because of their unknown durability.

But the proprietors of structures with eroded or damaged brick may not have an alternative. The integrity of a wall depends upon collective strength of each brick, after all.

Brick pathway with replaced bricks

  1. High-Pressure Chemical Cleaning Will Give an Old Structure that New-Building Sparkle.

Chemical cleaning employs acid-based cleaning compounds to break carbon buildup, stains, and pollutants from the surface of brick, granite, or stone masonry. Cost-effective and non-invasive, this is often a go-to for those looking to improve the aesthetics of their building on a budget.

With that said, there are a few cons to this approach. With such powerful chemicals, windows and stained glass are at risk for degradation. High-PSI pressure washing can be quite hard on finely carved stone, column fluting, and other minute details. We recommend only going this route once in a blue moon and ensuring that an effective sealant is applied afterwards.

Roof being power washed.

  1. Lintel Repair is More than Meets the Eye.

First, we’ll start by explaining what a lintel is, since it’s not an element of masonry that is typically exposed. Lintels are steel sections that are fastened above the windows and doors of a masonry structure, which act a shelf for the brick or stone above.

A few tell-tale signs that you may have lintel damage are: cracking around window panes, dropping or displacement around window arches, or bowing brickwork above doors and frames.

In older buildings, lintels were constructed of wood and tone, which made them susceptible to dry rot, fungus, and swelling. Nowadays, lintels primarily consist of steel, which are still subject to corrosion, but feature greatly improved longevity.

Ancient lintel made of stone.

Specializing in extensive masonry repair and rejuvenation, Cirigliano Masonry serves home and business owners throughout the Pittsburgh area. From design to build, as well as complete restoration options, rely on us for brick masonrypointing and repair. We also offer general masonry, stone repair, and more.  

Masonry Structures in the U.S.A.

A closer look at some significant stone structures … and the most mysterious!

Like countless other people throughout the world, early Americans recognized the value of building in stone. It was a natural choice for not only its beauty, strength and durability, but also its widespread availability as a building material.

From the historic to the strange, here are some examples of interesting masonry structures in America.

  • Pueblo communities in the southwest: The dwellings of the ancestral Puebloans rank among America’s oldest stone structures. Some of these masonry buildings were freestanding while others were constructed directly into cliffs. These adobe houses made extensive use of rock rubble and dry-stone walls as masonry materials. Many are still standing, and that’s a testament to the amazing durability of stone masonry in the construction of buildings.

 

Pueblo Buildings in Taos, New Mexico

 

  • Fieldstone structures in the northeast: In the Revolutionary Period (1775-1825) and well before it, farmers in New England came across large quantities of fieldstone when clearing their land. A plentiful resource, fieldstone soon was used to build chimneys, retaining walls and bridges, among other masonry structures.

 

Fieldstone Shed

 

  • First masonry home in New England: It wasn’t long before the practical settlers in the northeast began building larger structures of masonry. Constructed in 1639, the Henry Whitfield House in Guilford, Connecticut is the oldest stone house in New England. Featuring thick stone walls, this example of an early masonry building also served the community as a fort.

 

Henry Whitfield House

 

  • The oldest masonry fort in the continental U.S.: Construction of the Castillo de San Marcos in St. Augustine, Florida began in 1672. It was largely completed by 1695. Possession of the fort has changed many times, with all of the transitions peaceful! These included four different governments of Spain. Ownership also extended to Great Britain, the Confederate States of America and the U.S. — which currently maintains the old masonry-built fort through the National Park Service.

 

Castillo de San Marcos

 

  • The tallest freestanding masonry structure in the world: Completed in 1884 — 101 years after Congress authorized it — the Washington Monument in Washington, D.C. is an obelisk (i.e. pillar) that stands 555 feet high. Built of marble, this masonry monument is topped with solid aluminum — a rare building material at the time of its construction.

 

Washington Monument

 

  • An iconic, world-famous bridge: Linking Brooklyn and Manhattan, New York’s Brooklyn Bridge, is considered one the most complicated engineering feats in modern history. Built of limestone and granite, construction began in 1869. When the masonry structure opened 14 years later in 1883, it was the world’s largest suspension bridge … and an immediate sensation. More than 150,000 people crossed the bridge on its opening day alone!

 

Brooklyn Bridge

 

  • America’s own Stonehenge: England isn’t the only location for mysterious masonry structures. Mystery Hill is a 30-acre site of stone walls, standing stones and underground chambers in North Salem, New Hampshire. This Stonehenge-like masonry complex dates back 4,000 years. Like its stone-built counterpart in England, the monoliths are astronomically aligned. This very early example of masonry construction in America can still serve as an accurate yearly calendar!

 America's Stonehenge

 

Specializing in exterior natural stone additions and repairs, Cirigliano Masonry serves home and business owners throughout the Pittsburgh area. From design to build and extending to your full satisfaction, rely on us for brick masonry, pointing and repair as well as indoor and outdoor fireplaces, stone masonry, stone wall repairs and more.