Building Masonry Arches
Masonry arches can add immense character to homes, both internally and when used as part of the architectural style of the building. For instance in the house under construction on the left, large arched windows follow the same shape as the arched entrance that will welcome those entering the home. But building any sort of arch, even one that forms part of a garden plan, needs to be undertaken with great care, particularly if it is to span a wide opening.
The most widely accepted method of building arches is to use a supporting formwork that is cut in the shape of a semicircle, or to use hardboard (that you can see lining the inner surface at the top of the arch above) that is kept in place with battens cut to length.
Standards for Masonry Arches
In South Africa, the construction of masonry arches is contained in Part K, Walls of SANS 10400, which is, of course, a “deemed to satisfy” part of the National Building Regulations and National Standards Act.
Essentially, any circular masonry arch that has a span not exceeding 2,5 m must have an arch ring depth and proportions that meet the standards shown in the drawing below. Of course the walls that form the lower part of the arch must also be built in accordance with the Standard.
Construction of Masonry Arches
The Standard doesn’t give a lot of guidance, but it does say that the rise must be between 0,3 and 0,5 times the span of the arch. It also states that masonry units should be solid and that the arch ring should be constructed in either a header or a stretch pattern.
The depth of the arch ring should be no less than 200 mm where the rise is between half and two-thirds of the radius. It should be no less than 300 mm if the rise is greater than two thirds, but less than – or equal to – the radius. So a bit of basic mathematics is required here.
The guidelines given in the NHBRC handbooks is basically the same as in the SANS.
More About Masonry Arches
Masonry arches have a rich and varied history that spans thousands of years, with evidence of their use dating back to the ancient Greeks and Romans. Today, these arches are still used in a variety of applications, from architectural features in buildings to bridges and other infrastructure projects.
The use of masonry arches dates back to the ancient world, where they were commonly used in the construction of aqueducts and other public works projects. The ancient Greeks and Romans were skilled at using arches in their architecture, and their legacy can still be seen in the many surviving structures they built.
Aqueduct in France
One of the most famous examples of masonry arches from this time is the Pont du Gard, an aqueduct bridge in southern France that was built by the Romans in the 1st century AD. The bridge features three tiers of arches and was used to transport water from a spring to the city of Nimes.
In the Middle Ages, masonry arches continued to be used in the construction of buildings, bridges, and other structures. The Gothic architecture of this period is particularly famous for its use of pointed arches, which allowed for greater height and structural stability in buildings. The Notre Dame Cathedral in Paris, which was begun in the 12th century, is a prime example of Gothic architecture and features a number of masonry arches in its construction.
During the Renaissance, the use of masonry arches became more elaborate and decorative. In Italy, architects such as Filippo Brunelleschi and Andrea Palladio incorporated arches into their designs in a variety of ways, from grand entrances to ornate colonnades. The arch also became a popular decorative feature in garden design during this period, with many grand gardens featuring elaborate archways and trellises.
In the 18th and 19th centuries, masonry arches continued to be used in the construction of bridges and other infrastructure projects. This period saw the development of new materials and construction techniques, which allowed for even larger and more elaborate arches to be built. One of the most famous examples from this time is the Iron Bridge in Shropshire, England, which was built in 1779 and features a single arch made of cast iron.
Today, masonry arches are still used in a variety of applications, although advances in technology and engineering have allowed for new materials and construction techniques to be used as well. In architecture, masonry arches are often used as decorative features in buildings, providing an elegant and timeless design element that can be incorporated into a variety of styles.
In bridge construction, masonry arches are still used in some cases, although other materials such as steel and concrete are more commonly used due to their greater strength and durability. However, masonry arch bridges are still built in some situations, particularly in areas where there is a need for a more traditional or historic appearance.
One area where masonry arches continue to be used extensively is in infrastructure projects such as tunnels and underground passageways. The inherent strength and durability of masonry makes it an ideal material for these types of projects, where the ability to withstand high levels of pressure and stress is essential.
In recent years, there has also been a growing interest in the use of masonry arches in sustainable construction. The use of natural materials such as stone and brick can help to reduce the environmental impact of construction projects, while the inherent durability of these materials means that structures built with them can last for centuries or even millennia.
Masonry arches have a long and rich history that spans thousands of years, and their use continues to this day in a variety of applications. From the ancient aqueducts of the Romans to the grand architecture of the Renaissance, masonry arches have played a key role in shaping the built environment of our world. Masonry arches offer several benefits, including their strength and durability, their ability to span large distances without the need for supporting columns, and their aesthetic appeal.
Use Correct Materials
To construct a masonry arch, it is important to follow certain principles and guidelines to ensure its stability and longevity. This includes selecting appropriate materials, such as high-quality bricks and mortar, and carefully calculating the arch’s dimensions and angles to ensure proper weight distribution and load-bearing capacity. It is also important to pay attention to the details, such as the use of keystones and voussoirs, to ensure the arch is structurally sound.
Today, masonry arches continue to be used in a variety of applications, from decorative garden features to structural elements in bridges and buildings. They offer a timeless and classic design element that can enhance any architectural style, and their durability and strength ensure they will continue to be a part of our built environment for many years to come.