What Is Lathing in USA: A Comprehensive Construction Guide

Understanding Lathing in American Building Practices

In the United States, lathing plays a fundamental role in the construction and finishing processes of both residential and commercial structures. It refers to the installation of a supportive base—known as lath—that serves as the substrate for plaster, stucco, stone veneer, or other surface finishes. Whether restoring historical architecture or constructing new energy-efficient buildings, lathing in USA remains an essential and versatile component of wall and ceiling assemblies.

Types of Lath Materials Used in U.S. Construction

Wood Lath

Wood lath consists of narrow wooden slats, usually around ¼ inch thick and 1 to 2 inches wide, spaced slightly apart and nailed directly to framing. It was the standard lathing method in the U.S. from the 18th century through the early 20th century. Though largely obsolete today, wood lath is still used in historic preservation projects and custom plaster work.

Metal Lath

Metal lath has replaced wood lath in most contemporary construction. It offers superior durability, fire resistance, and moisture tolerance. The primary types include:

• Expanded Metal Lath (EML): Created by slitting and stretching sheets of galvanized steel to form diamond-shaped openings. Widely used for stucco systems and plaster base.
• Welded Wire Lath: Provides even spacing and strong support, ideal for concrete reinforcement and thick stucco applications.
• Self-Furring Metal Lath: Features built-in dimples that create space between the lath and sheathing, eliminating the need for additional furring.
• Strip Lath and Corner Beads: Used for detailing, reinforcing corners, and creating clean terminations or expansion joints.

Gypsum Lath and Blueboard

Modern alternatives to traditional lath include gypsum lath boards and blueboard, which are prefabricated gypsum panels designed for veneer plaster finishes. These offer faster installation and uniform surfaces while maintaining plaster’s classic appearance.

The Role of Lathing in Plaster and Stucco Systems

Interior Applications

In interior walls and ceilings, lathing provides the mechanical keying that allows plaster to bond securely. A traditional three-coat plaster system includes:

1. Scratch Coat – Applied over the lath and scored to create a textured surface.
2. Brown Coat – A leveling layer to add strength and shape.
3. Finish Coat – A smooth or textured surface finish.

Exterior Stucco Systems

In exterior wall construction, lath serves as the foundation for stucco systems. When combined with water-resistive barriers (WRBs) and weep screeds, it forms a complete drainable cladding system that protects the building envelope from moisture intrusion.

Furring Systems and Fastening Techniques

To ensure proper lathing installation, we use furring systems that provide spacing and support between the lath and the underlying substrate. These include:

• Wood Furring Strips
• Galvanized Steel Channels
• Plastic Spacer Systems

Fasteners such as galvanized nails, stainless steel screws, and tie wires are used depending on the type of lath and substrate. Proper fastener placement—usually 6 inches on center at supports—is essential for structural integrity and code compliance.

Moisture Management Behind Lath Assemblies

For exterior applications, moisture control is critical. Behind the lath, we apply two layers of WRBs, such as:

• Grade D Building Paper
• Housewrap (e.g., Tyvek StuccoWrap)
• Liquid-Applied Membranes

These membranes prevent water infiltration while allowing vapor transmission, protecting both the structure and the finish material.

Fire Resistance and Building Code Compliance

Lath and plaster wall systems offer high fire resistance ratings, often used in multi-family housing, commercial buildings, and fire-rated partitions. Assemblies that meet ASTM E119 fire endurance standards often include:

• Metal lath over Type X gypsum board
• 7/8-inch total plaster thickness
• Reinforced corners and firestopping measures

We ensure all lath installations comply with ICC building codes, ASTM C847 (for metal lath), and ASTM C1063 (for lath and plaster application).

Acoustical and Thermal Benefits of Lath Construction

Lath assemblies provide substantial sound attenuation and thermal mass. Plaster over lath can achieve STC ratings over 55, making it an excellent solution for media rooms, apartments, and classrooms. Additionally, the dense plaster material helps stabilize indoor temperatures, contributing to energy efficiency.

Lathing in Historical Restoration Projects

In the realm of preservation construction, we use authentic lathing methods to restore period architecture. This often includes:

• Hand-nailed wood lath over balloon framing
• Traditional lime or gypsum plasters
• Hand-troweled finishes to match historical textures

Historic lathing also calls for attention to plaster keys, scratch coat adhesion, and curved lath work for domes or vaulted ceilings.

Modern Innovations in Lathing Systems

Pre-Fabricated Lath Panels

Modular lath sheets, factory-assembled for speed and consistency, are increasingly used in large-scale commercial projects. These offer:

• Reduced labor time
• Consistent fastener spacing
• Minimal material waste

Synthetic Lath (Plastic Lath)

Plastic lath, made of HDPE or fiberglass mesh, is corrosion-resistant and suitable for coastal or high-humidity environments. It’s compatible with cementitious and acrylic coatings and meets ICC requirements.

Common Tools in Lathing Construction

To execute quality lath work, professionals rely on a precise set of tools:

• Lath Hammers
• Plaster Hawk and Trowel
• Tin Snips and Aviation Shears
• Staplers and Tie Wire Tools
• Levels and Screeds
• Scratch Rakes

Skilled lathers ensure lath is flat, tight, and ready to support a long-lasting finish.

Inspection, Testing, and Quality Assurance

Before applying plaster or stucco, building inspectors verify:

• Fastener spacing
• Moisture barrier coverage
• Lath overlap (minimum 1 inch)
• Integration of control joints

We adhere to strict QA protocols and third-party inspection requirements to deliver superior craftsmanship on every project.

Lathing Across Building Sectors in the U.S.

Residential Construction
Lath is commonly found in:

• Custom homes
• Luxury interiors
• Stucco-clad exteriors

Commercial Construction
Used in:

• Office complexes
• Retail façades
• Fire-rated corridor walls

Industrial Applications
Employed for:

• Mechanical enclosure linings
• Warehouse soundproofing
• Durable wall assemblies

Conclusion

Lathing in USA construction remains one of the most essential components in creating durable, resilient, and beautifully finished structures. Whether using traditional wood lath, modern galvanized mesh, or synthetic alternatives, we ensure every layer is installed with precision, code compliance, and longevity in mind.

Our commitment to expert lathing practices continues to support the evolution of American building systems—ensuring strength, beauty, and performance across every project.