Furr Out Wall Meaning in Construction in USA

In the realm of U.S. construction, the phrase “furr out wall“ refers to the method of extending or building out an existing wall surface using wood or metal furring strips. This construction technique is widely used in both residential and commercial settings to accommodate insulation, provide a flat surface for finishes, conceal plumbing, wiring, or HVAC systems, and correct irregularities in existing structures.

Definition of Furring Out a Wall in Construction

To furr out a wall means to add a secondary framing layer to an existing masonry, concrete, or framed wall. This secondary framework is usually made up of wood furring strips or metal furring channels that are installed vertically or horizontally, depending on the application.

The primary goals when we furr out a wall include:

• Creating space for mechanical systems or insulation
• Correcting alignment or out-of-plumb surfaces
• Preparing for the installation of drywall, paneling, or tile
• Meeting building code requirements for fire ratings or energy efficiency

Materials Used to Furr Out a Wall

Wood Furring Strips

• Standard Sizes: 1×2″, 1×3″, or 2×2″
• Common Wood Species: Spruce, Pine, or Fir
• Pressure-Treated Wood: Used in areas with high moisture exposure, such as basements

Wood furring is often used in residential applications due to its availability and ease of installation.

Metal Furring Channels

• Hat Channels: Most commonly used metal profile
• Z-Channels: Provide spacing and support in curtain wall assemblies
• Material: Cold-formed galvanized steel

Metal furring systems are preferred in commercial and multi-unit residential buildings, especially where fire-resistance or moisture management is a concern.

Situations Where Walls Are Furred Out

1. Installing Drywall Over Masonry

Masonry surfaces such as concrete block or brick are typically not smooth or suitable for direct drywall attachment. Furring out the wall:

• Provides a secure nailing or screwing surface for drywall
• Allows for cavity insulation between furring members
• Enables placement of electrical boxes and conduits

2. Correcting Wall Irregularities

Walls that are warped, uneven, or out of square can be furred out to create a flat plane.

• Shims are used behind furring strips to adjust alignment
• Ensures better results in finishing stages
• Especially useful in historic renovations or older homes

3. Concealing Mechanical, Electrical, and Plumbing Systems

In modern buildings, it’s often necessary to run plumbing pipes, electrical wiring, or ductwork inside walls. Furring out provides:

• Extra depth for accommodating larger systems
• Routing paths for smart home wiring, security systems, or audio cabling
• Aesthetic concealment without altering the structural wall

4. Enhancing Insulation and Energy Efficiency

When energy performance is a priority, especially in cold or hot climates, furring allows the addition of rigid foam board, mineral wool, or fiberglass insulation.

• Improves R-values
• Supports continuous insulation strategies
• Helps reduce thermal bridging in wall assemblies

5. Creating Fire- or Sound-Rated Assemblies

In multi-unit buildings or areas requiring code-compliant separation, furring helps to create assemblies with:

• Fire resistance ratings (1-hour, 2-hour)
• Sound transmission class (STC) improvements
• Support for Type X drywall and other fire-rated materials

Step-by-Step: How We Furr Out a Wall

1. Planning and Layout

• Measure and mark wall areas to be furred
• Determine furring strip spacing, typically 16″ or 24″ on center
• Assess location of electrical boxes, mechanical systems, and insulation

2. Attaching Furring Strips

For Wood Furring:

• Use Tapcon screws, powder-actuated fasteners, or masonry nails on concrete or block
• Use screws or nails on wood-framed surfaces

For Metal Furring:

• Attach using mechanical anchors, tie wire, or suspension clips
• Maintain plumb and level positioning

3. Installing Insulation

• Place rigid foam, fiberglass batts, or spray foam between furring strips
• Add vapor barriers or air retarders if required by building code
• Tape and seal all joints for air-tightness

4. Adding the Finish Layer

• Install drywall, cement board, or paneling
• Use screws compatible with the underlying furring material
• Stagger seams and follow best practices for surface finish

Code Compliance When Furring Out Walls

When we furr out walls in the U.S., we adhere to:

• IRC (International Residential Code)
• IBC (International Building Code)
• ASHRAE 90.1 for thermal efficiency
• NFPA standards for fire resistance
• ADA clearance requirements when modifying walls in public buildings

Inspectors may verify:

• Fastening methods
• Material compatibility
• Fire and sound ratings
• Insulation continuity
• Proper clearances and alignment

Advantages of Furring Out Walls in U.S. Construction

Increased Design Flexibility

Furring provides the opportunity to customize wall depth for storage niches, built-in lighting, or flush-mounted systems.

Improved Performance

Properly furred walls deliver enhanced thermal, acoustic, and fire performance—key for multifamily dwellings, schools, hospitals, and commercial offices.

Aesthetic Cleanliness

By enabling a flat and plumb surface, furring eliminates visual inconsistencies and creates a professional, finished look.

Adaptability in Renovations

In retrofitting or remodeling projects, furring is a vital technique to modernize outdated walls without complete demolition.

Furring Out Walls vs. Adding Stud Walls

When space is at a premium, especially in basements or tight corridors, furring out is the superior method.

Cost Considerations

The cost of furring out a wall depends on:

• Material type (wood vs. metal)
• Wall length and height
• Presence of mechanical systems
• Type of finish material
• Local labor rates

On average:

• Wood furring: $1.00 – $2.50 per square foot installed
• Metal furring: $2.00 – $4.00 per square foot installed
• Add $1.50 – $3.00 per square foot for drywall and finishing

Conclusion

Furring out a wall in U.S. construction is a fundamental and highly effective technique for modifying and improving wall systems. It enables builders and remodelers to adapt existing structures for modern needs—whether for insulation, mechanical routing, sound isolation, or fire safety. By utilizing wood or metal furring strips, we can transform uneven, outdated, or unfinished wall surfaces into code-compliant, energy-efficient, and visually appealing components of the building envelope.

Whether in a new build, remodel, or tenant improvement project, the ability to furr out walls gives us the flexibility and functionality needed to deliver high-performance buildings that meet both regulatory and design expectations.

Always consult a licensed contractor or building inspector to ensure compliance with local regulations and best practices.