Furr Out Wall in Construction in the USA
Understanding Furring Out Walls in Construction
The term “furr out” in the context of construction refers to a process where a wall is built out or extended to either create space or ensure the correct alignment of other building components. It typically involves attaching furring strips (thin strips of material such as wood or metal) to an existing surface, often to create a gap between the wall and finish material. This process is common in both residential and commercial construction across the United States.
When walls are furred out, this procedure can be done for several reasons including creating room for insulation, hiding electrical wiring, or ensuring a flat surface for drywall installation. Understanding when and why to furr out a wall is critical in the construction industry to achieve the best results for building stability, efficiency, and aesthetics.
Why Furring Out Walls is Essential in Construction
1. Leveling Uneven Walls
One of the primary reasons for furring out a wall is to level uneven surfaces. Older buildings, especially those constructed with brick or block walls, may have natural imperfections or irregularities. Attaching furring strips allows the construction team to create a level surface, ensuring that finishing materials such as drywall, paneling, or plaster adhere evenly. This step is especially important in remodeling projects where the goal is to update or improve existing structures.
2. Providing Space for Insulation
Furring out walls is also an effective way to create space for insulation. This is particularly important in ensuring that the building complies with local energy codes. In areas like cold climates, adding insulation to the interior walls not only helps in temperature regulation but also improves the building’s overall energy efficiency. The gap created by the furring system can accommodate insulation types such as fiberglass, foam boards, or spray foam.
Additionally, furring out provides space to incorporate modern insulation methods, such as rigid foam or cellulose insulation, which significantly enhances thermal performance.
3. Concealing Wiring and Plumbing Systems
In both new construction and renovations, it is often necessary to conceal electrical wiring, plumbing, or HVAC ducts. Furring out a wall creates a gap where these systems can be hidden. This setup is essential for aesthetic purposes, allowing for cleaner and more organized spaces. In some cases, the gap also provides the flexibility needed for future upgrades or maintenance of the mechanical systems.
This function is particularly valuable in commercial spaces or multi-family buildings, where wiring and plumbing are frequently routed through interior walls, and easy access is a priority.
4. Moisture Control and Ventilation
In certain construction applications, such as in basement walls or exterior-facing walls, moisture control becomes an essential consideration. By furring out walls, a ventilation gap is created, which allows air to circulate behind the wall finishes. This promotes airflow, helps prevent the buildup of moisture, and reduces the risk of mold or mildew. For structures located in humid environments, such as along the coastal regions of the United States, managing moisture is critical to preserving the structural integrity of a building.
In rainscreen systems, the gap created by furring can also act as a drainage plane, allowing water to escape and preventing moisture from affecting the underlying structural components.
Materials Used for Furring Out Walls
1. Wooden Furring Strips
The most commonly used material for furring out walls in residential and light construction projects is wood. Wooden furring strips are cost-effective, easy to work with, and widely available. Typically, 2×4, 2×3, or 1×3 wood strips are used. These strips are often fastened to the existing wall with nails or screws.
Wooden strips can also be pressure-treated to resist moisture, making them ideal for use in areas where humidity levels are high, such as in basements or bathrooms. Moreover, they are easy to modify, making it easier for contractors to adjust the furring system to accommodate different wall sizes or uneven surfaces.
2. Metal Furring Channels
For commercial and industrial applications, metal furring channels offer greater strength and durability. These channels are typically made from galvanized steel or aluminum and come in various sizes and shapes to suit specific structural needs. Metal furring is especially suitable for fire-rated systems and high-performance building designs. The inherent properties of metal allow it to withstand harsh environments and provide long-term durability.
Metal furring channels are commonly installed using screws or anchors that are secured to the wall or ceiling. The benefit of using metal is its resistance to moisture, termites, and mold, making it a preferable option in areas with high humidity or where long-term performance is required.
3. Composite Furring Strips
An emerging trend in construction is the use of composite materials for furring systems. These materials are made from recycled plastics, fiberglass, or other sustainable compounds. Composite furring strips provide the benefit of being lightweight, durable, and resistant to moisture. Additionally, composite materials are less likely to warp, rot, or decay over time, making them ideal for environments with fluctuating temperature and humidity.
While composite furring strips tend to be more expensive than wood, they offer long-term savings by requiring less maintenance and having a longer service life.
Furring Out Walls: Step-by-Step Installation Process
1. Preparation and Planning
Before beginning the furring process, it is essential to conduct a thorough assessment of the existing wall structure. Identify any issues with unevenness, moisture damage, or electrical/plumbing routes. Based on the findings, decide on the best material and method for furring out the wall.
It’s also important to gather the necessary tools, which may include measuring tape, level, screws, nails, power drill, and furring strips.
2. Attaching the Furring Strips
Once the wall is prepared, furring strips are attached to the existing wall structure. For wood furring, ensure that the strips are spaced correctly, usually 16 or 24 inches apart, depending on the requirements of the finishing materials. Metal furring may require additional tools such as anchors to secure the channels properly to masonry or concrete walls.
During installation, regularly check the level and plumb of the furring system to ensure accuracy. If necessary, use shims to level out any discrepancies in the surface.
3. Adding Insulation or Other Materials
Once the furring strips are in place, you can install insulation or run electrical wiring, plumbing, or ductwork through the cavity created by the furring system. It’s essential to ensure that these systems are appropriately sealed and that insulation is installed without gaps.
For insulation, ensure that the material fits snugly within the gap without compression. Compression can reduce the R-value and lower the system’s effectiveness in thermal insulation.
4. Securing the Finishing Material
Finally, once everything is in place, secure the finish materials such as drywall, paneling, or other cladding to the furring strips. Ensure that the fastening system is appropriate for the material being used and that it is securely attached to avoid sagging or future maintenance issues.
Conclusion
Furring out walls is a fundamental aspect of construction in the United States, offering solutions for leveling surfaces, improving insulation, concealing systems, and controlling moisture. Whether used in residential, commercial, or industrial settings, the benefits of furring cannot be overstated.
By selecting the appropriate materials, following a precise installation process, and adhering to best practices, furring out a wall helps ensure that the finished product is not only aesthetically pleasing but also functional, durable, and energy-efficient. This simple yet effective construction technique continues to be a cornerstone of modern building practices, delivering consistent results in creating well-organized and efficient spaces.
