The term "furring" derives from the historical root word "furr," which designated the specific space created behind the field of lath in traditional construction. This practice of intentionally creating a gap behind a surface is fundamental to its name.
Understanding the Origin of Furring
At its core, furring refers to the process of installing thin strips of material, known as furring strips, to create a level surface or an air gap between a structural element and a finish material. The name itself reflects its original function: to create a "furr" or space.
The Historical Context
Historically, when plaster was applied to lath, a small gap or "furr" was naturally or intentionally left or created behind the lath framework. This space was crucial for the proper drying and adhesion of plaster and served various other practical purposes. The strips of wood or metal that create this space became known as furring strips, and the act of installing them is furring.
What Is Furring?
Furring is a construction technique where strips of wood or metal are fastened to a wall, ceiling, or floor to provide a level surface, create an air space, or offer a nailing base for finish materials. These strips essentially "fur out" the surface, pushing it away from the structural element.
Key Purposes and Benefits of Furring
Furring is a versatile technique used in various construction scenarios to achieve specific functional and aesthetic goals.
1. Leveling Uneven Surfaces
One of the primary uses of furring is to create a perfectly flat and plumb surface over existing walls or ceilings that may be irregular, warped, or out of alignment. This is crucial for applying new finishes like drywall or paneling cleanly.
2. Creating an Air Gap or Ventilation
Furring can establish an essential air space between different building components. This gap can:
- Improve insulation: By creating a thermal break, reducing heat transfer.
- Prevent moisture buildup: Allowing air circulation to dry out condensation or trapped moisture, especially in exterior wall assemblies.
- Aid in acoustics: Contributing to soundproofing by separating layers.
3. Providing a Nailing or Fastening Base
Furring strips offer a solid, continuous surface to attach finish materials. For example, a furred-out wall provides a consistent nailing surface for drywall or paneling, ensuring a strong and even application.
4. Accommodating Utilities
The space created by furring can be used to run electrical wiring, plumbing pipes, or HVAC ducts without cutting into the main structural elements, keeping them hidden and protected.
5. Enhancing Fire Resistance
In certain applications, particularly in commercial projects or areas with strict fire codes, specific types of furring are mandated. Metal furring strips, for example, are often used where fire-proof supporting elements are required by local building codes, as they do not contribute to the spread of fire like wood might.
Types of Furring Strips
The material used for furring strips varies depending on the application and requirements.
| Type of Furring Strip | Common Material | Primary Use Cases | Key Advantage |
|---|---|---|---|
| Wood Furring | Lumber (1x2, 1x3) | Residential, interior walls, ceilings, traditional plaster | Easy to cut and fasten, cost-effective |
| Metal Furring | Galvanized steel | Commercial, exterior applications, fire-rated assemblies | Non-combustible, durable, uniform |
Wood Furring Strips
These are typically thin strips of wood, commonly 1x2 or 1x3 lumber, used in residential construction for interior walls and ceilings. They are easy to cut, install, and provide a good surface for nailing.
Metal Furring Strips
Made from galvanized steel, metal furring strips are common in commercial construction, large-scale projects, and scenarios demanding higher durability or specific safety standards. As mentioned, metal furring strips are often specified for projects, or in towns where fire-proof supporting elements are required by the local building code, due to their non-combustible properties.
For more information on building practices, you can explore resources on construction terminology or building codes.
