Party wall construction plays a crucial role in the development of townhouses, condominiums, and duplexes. It is an important aspect that ensures structural integrity, privacy, and sound insulation between adjoining properties. Party walls are strategically placed to separate individual units within a shared structure, to provide privacy, fire protection, and structural stability.

In this article, we will explore the essential aspects of party walls, and compare traditional construction methods with the technologically advanced solution called ICFs (Insulated Concrete Forms).

What is a Party Wall in Construction?

In construction, a party wall refers to a partition between two adjacent buildings that is shared by the occupants of each residence or business. It serves as a boundary wall, and effectively separates two separate units within the same structure to help ensure a high level of privacy, comfort, and safety for the occupants.

Common Party Wall Code Requirements

Building codes vary by country, state, and municipality. However, many building codes share common strict requirements when it comes to party wall construction due to the shared wall issue and its potential implications for safety, privacy, and structural integrity. Here are some of the strictest and most common requirements:

Fire Resistance: One of the primary functions of a party wall is to prevent the spread of fire between adjoining units. Building codes often require party walls to have a specific fire-resistance rating that is often measured in hours and indicates how long the wall can resist a fire before being breached.

Sound Transmission: Due to privacy concerns, party walls need to provide a certain level of soundproofing. Building codes may specify a minimum Sound Transmission Class (STC) rating to ensure the wall sufficiently dampens sound transmission between units.

Structural Integrity: The wall must be sturdy and able to bear the load of the building. Codes will specify the kind of building materials that can be used and how the wall should be anchored to ensure it doesn't collapse or shift over time.

Height and Depth: Many codes will outline how tall a party wall must be, and often require it to extend continuously from the foundation to the roof. Additionally, there may be requirements for how deep the wall goes below ground, particularly if the units have basements.

Insulation: In colder climates, certain building codes may include requirements for insulation type and thickness that aim to enhance energy efficiency and minimize heat loss.

Materials: Depending on the locality, there may be restrictions or specifications on the type of materials that can be used. For instance, in some areas prone to earthquakes, masonry walls might need to be reinforced with steel.

Access and Maintenance: Some codes may require provisions for access to the party wall for maintenance or inspection. This can be particularly relevant in cases where one side of the wall is responsible for upkeep.

Joints and Seams: To ensure the wall's effectiveness, there might be requirements on how joints and seams are sealed to prevent sound, fire, or even pests from traveling through gaps.

Ventilation and Damp Proofing: In some regions, especially those with high humidity, building codes may have strict requirements for preventing moisture buildup in and around party walls. They might involve the inclusion of damp proof courses or specific ventilation measures.

Additional Features: Depending on the building's purpose, there might be added requirements, such as the inclusion of electrical or plumbing lines within the party wall. These would need to be safely and securely integrated to ensure they don't compromise the wall's primary functions.

Builders and architects should always consult local building codes and regulations before constructing a party wall to ensure compliance. Non-compliance can lead to legal issues, penalties, and even the potential need to redo the construction.

Traditional Party Wall Construction Methods

Over the years, there have been various methods employed in party wall building. Typically, party walls have been constructed using bricks, blocks, or timber, with insulation sandwiched between the layers. While these materials do provide a decent level of sound and heat insulation, they come with their own set of challenges:

Cost: Traditional materials can be expensive and require more labor-intensive processes.

Time: Building a brick or timber party wall takes time that can sometimes delay the overall project.

Durability: Over time, the walls can degrade, which can lead to potential issues with sound leakage and/or decreased fire resistance.

Introducing Insulated Concrete Forms (ICFs)

Party walls, which are essentially dividers between adjacent dwellings, can be constructed using various methods, with traditional and Insulated Concrete Form (ICF) being the most prevalent. Both methods share some foundational benefits, however, a deeper dive reveals that ICF construction provides enhanced advantages and brings unique features to the table that traditional methods can't rival.

Shared Benefits: Traditional Party Wall vs. ICF Party Wall

Fire Resistance: Traditional party wall construction and ICF party walls are designed to be fire-resistant, and both offer protection against the spread of fire between adjoining units. Sound

Transmission: Traditional and ICF walls provide soundproofing between units, to help prevent noise leakage and ensure privacy for occupants.

How ICF Construction Enhances These Benefits

Superior Fire Resistance: While traditional party walls offer fire resistance, ICF walls often surpass them. The combination of concrete sandwiched between insulating layers can provide several hours of fire resistance, often outperforming the fire resistance time span of traditional materials. ICFs have been tested to meet ASTM and ULC standards for 2 to 4 hour fire resistance ratings.

Enhanced Soundproofing: ICF walls generally have a higher Sound Transmission Class (STC) rating compared to many traditional party walls. The density of concrete combined with the insulating properties of the foam can provide a better barrier against sound transmission.

Additional Benefits of ICF Party Wall Construction

Speed and Simplicity of Installation: ICFs are modular and interlocking, which makes them quick and easy to install. Traditional walls, especially those made of brick or block, require more time for layering and setting.

Energy Efficiency: ICF walls provide excellent thermal insulation because of their foam-concrete-foam composition. This translates to significant energy savings, as it helps maintain a consistent indoor temperature, and reduces the load on heating and cooling systems.

Strength and Durability: ICF walls are highly resistant to natural disasters like earthquakes, hurricanes, and floods. Their integrated structure ensures long-lasting durability, with less worry about degradation or wear and tear over time.

Cost-Effective: Although the initial cost of ICF may be comparable to or slightly higher than some traditional methods, the energy efficiency, reduced maintenance, and longevity it provides can make it a more practical and cost-effective solution in the long run.

Versatility in Design: ICFs offer flexibility in design and allows various architectural features and finishes to be integrated more easily than with traditional methods. ICF fire rated party walls are thinner than traditional double wood stud firewalls, saving valuable square footage.

Moisture and Mold Resistance: The nature of ICF construction provides an inherent resistance to moisture ingress, which in turn reduces the potential for mold growth, to help ensure a healthier living environment.

Air Infiltration: ICFs as a party wall provide a continuous air barrier between units. This eliminates cross-contamination of indoor air and odor transfer.

Traditional party wall construction and ICF party wall construction share some fundamental benefits, however, ICFs have more advantages. The unique features of ICF construction are additional benefits that traditional methods simply can't match. For builders and homeowners seeking optimal performance, longevity, and efficiency, ICFs are a compelling choice.

Build Better Party Walls with Fox Blocks ICFs

At Fox Blocks, we're committed to providing superior building solutions for our clients. Our Insulated Concrete Forms (ICFs) not only deliver the key benefits associated with traditional party wall construction, but they also provide enhanced fire resistance, soundproofing, and energy efficiency—plus additional advantages like durability, cost-effectiveness, and design flexibility.

Contact us today to find out more!