What is a Parapet wall? Function, Types, Features, and Selection Criteria

A parapet wall is a wall that builds at the edge of a roof to prevent people or objects from falling off. Parapets usually provide around the perimeter of buildings and have various functions, including adding aesthetic appeal and protecting against damage. Depending on their use and placement on a building, parapets can build in various ways.

Parapet Wall ( Image Source – Adobe Stock)

The most common types of parapets include:

•Safety precautions include the use of coping walls and guardrails.

• Decorative parapets, which add visual interest.

• Solid parapets, which support the weight of a building’s structure.

The function of the Parapet Wall

Safety 

Parapet helps prevent people from falling off the edge of the building

Use of space

Parapet walls in new construction projects protect the foundation of a home built on a slope. Usually, parapet walls are the same height as the roof, but they can also be taller than the roof if there needs to be more room for the wall to extend under the roofline.

Aesthetics

Having parapet walls on the property helps from potential falls and provides an aesthetic touch.

Privacy

A parapet wall serves as a visual obstruction, ensuring space privacy. Additionally, it could conceal unappealing items typically kept on the terrace, such as pumps and tools, improving the building’s appearance.

Upholds against wind

They must withstand wind, rain, and other weather conditions that may deteriorate the walls over time.

Ensures a clean appearance

Parapet walls keep water from flooding the basement by directing the water into gutters and downspouts. Parapet walls prevent debris from falling off the roof of a building and onto pedestrians below.

Types of Parapet Wall

As such, parapet walls come in various shapes and sizes, each with its unique characteristics. According to their appearance, parapet walls can be divided into the following categories:

Plain / Solid Parapet Wall

The most common type of parapet wall is the solid wall. Solid parapet walls consist of concrete, brick, or stone. There are no gaps between these solid walls, which run the length of the building. They are most prevalent in locations where safety takes priority over aesthetics. They are the strongest type of parapet wall and are common in commercial and industrial buildings. However, solid parapet walls can be quite expensive and are only sometimes the best choice for residential buildings. The most common type of alternative to a solid wall is a perforated one.

Plain Parapet Wall (Image Source – Adobe Stock)

Embattled parapet walls / Perpetrate Walls

Embattled Parapet Wall (Image Source -Adobe Stock)

These are architectural elements attached to the outer edge of a roof. The parapet wall supports the roof and often contains decorative elements such as window frames, decorative muntins, and other ornaments. These types of parapets were common in medieval times but were common in architecture, roofing, and fortification.

Perforated Parapet Walls

They are a special type of wall that separates a taller building from the ground. Parapets usually consist of concrete or stone and protect against falling objects and weather and water damage. The construction of these walls is to provide safety for people on the top floor of a building while still allowing them to enjoy the outside environment. Perforated parapets provide on the upper floors of residential buildings, but they can also be for commercial buildings or other structures.

Perforated Parapet Wall (Image Source – HomeLane)

Paneled Parapet Walls or Double Walls

Paneled Parapet Wall (Image Source -Civiconcepts)

A Paneled Parapet Wall uses the same principle as a Single Wall but adds an extra layer of insulation in the cavity. Double walls are using two sheets of cladding (the outer skin), separated by an air gap filled with insulation. Unlike a single wall, this insulation does not extend into the roof space. Double walls will perform better in hot climates than ordinary single-wall parapets by keeping the roof cool for longer, making the home cooler. Paneled parapet walls use vertical paneling, with a horizontal band at the top and bottom. This creates a sense of openness while still maintaining privacy.

Additionally, parapet walls can be divided into the following groups according to their configuration and shape:

Sloped Parapet Wall

Sloped Parapet Wall (Image Source – Adobe Stock)

 A sloped parapet wall is a continuous exterior wall with a slope of not more than 45 degrees from the horizontal. It may be constructed with parapet walls of various heights but must have its lowest face open. The width of the parapet wall shall be at least three times its height (or depth). They help reduce the risk of people falling from the roof by providing a sloping surface for them to walk along, and they give the building exterior a much more attractive facade. They generally consist of bricks or stones.

Flat Parapet Wall

Flat parapet walls are a type of wall used in combination with roofs and flat roofs. They serve to protect the roof from rain and snow, as well as to prevent visual intrusion. Unlike conventional parapets, flat ones do not protrude above the roofline and thus do not interrupt the aesthetic appearance of a building. 

Flat Parapet Wall – (Image Source – Pinterest)

Stepped Parapet Wall

Stepped Parapet Wall (Image Source – Expert Civil)

They are a series of steep steps that extend out from the top of an otherwise flat or low-angled roof. They are built onto the side of a building and extend for several feet on either side. Some stepped parapet walls also include overhangs that extend past the first step. Stepped parapet walls have multiple levels stacked at different heights. They are often used as decoration in architecture and sometimes include ledges for sitting or standing. They often have arches or windows on the sides and are commonly used as decorative.

Curved Parapet Wall

The term “arch parapet walls” also refers to curved parapet walls. These types of parapet walls are typically provided for flat and inclined roofs. Curved parapet walls make a building appear larger. These offers the structure a stylish and appealing appearance.

Curved Parapet Wall (Image Source – Happho)

Selection Criteria of Parapet Wall

The criteria for parapet walls should be selected based on the required load and structural capacity, often defined by the building code.

Wind and Seismic Protection Index 

The wind load is resistant to the pressure and external force, which mainly composes of two components: the internal component, i.e., the building itself, and the external component – due to the effect of wind on the building envelope. The total load can calculate by summing these two components. The direction of force does not change when it hits an obstacle or obstruction. If a structure has weak resistance to seismic impact or displacement, it will easily cause asymmetry in seismic energy and lead to overturning collapse or catastrophic collapse at worst. In some cases, buildings may collapse sideways due to strong vibrations caused by seismic forces. 

Structural Basis 

When selecting parapet walls to enhance stability, they must have suitable strength at critical positions under various boundary conditions such as dead weight, live load, seismic action, etc. Therefore, their design should cover all aspects, from fundamental aspects to overall structure optimization, to ensure safety during normal use and emergencies.

Points to keep in mind:

1) For the outside of the parapet wall, select a durable and weather-resistant material. 

2) The material should shield against wind and water penetration. 

3) For the inside of the parapet wall, select a durable material that provides good thermal comfort and has sound-insulating properties. 

4) The material should not be sensitive to extreme temperatures or moisture. 

5) Materials used for both the inside and outside may differ if desired but should be compatible in terms of having similar durability and mechanical characteristics. 

6) If there are windows in the building or on the floor below, consider placing a layer of foam or other sound-insulating material between the two walls so as not to transmit noise from one side to another.

What is the importance of parapet walls?

The parapet helps prevent people from falling off the edge of the building. They are designed to withstand wind, rain, and other weather conditions that may deteriorate the walls over time. Parapet walls are used to prevent debris from falling off the roof of a building and onto pedestrians below.

What are the different types of parapet walls?

Based on their appearances, they are classified as Plain, Embattled, Perforated and Paneled parapet walls. Based on their shape, they are classified as sloped, flat, stepped and curved parapet walls.