What Is Expanded Metal Lath?

Expanded metal lath is a lightweight, rigid expanded metal sheet specifically designed for construction. It is made by slitting and stretching thin-gauge steel or metal into a uniform diamond pattern, creating a strong, flexible base for plaster, stucco, cement, and mortar.

Unlike paper lath or fiberglass mesh, metal lath provides superior structural reinforcement, prevents cracking, improves adhesion, and extends the lifespan of walls and ceilings. The different types of expanded metal lath are engineered for specific indoor, outdoor, and specialty construction needs.

At our metal mesh manufacturing facility, we produce all standard and custom types of expanded metal lath in compliance with ASTM C1063, the international standard for construction lath products.

Primary Types of Expanded Metal Lath (By Design & Structure)

The most common way to classify expanded metal lath is by its physical structure and rib design, which determines strength, flexibility, and application.

This is the most widely used type of expanded metal lath, featuring a classic diamond pattern with uniform openings. It offers balanced strength and flexibility for general construction.

• Universal design for interior and exterior use
• Excellent plaster and stucco adhesion
• Used for walls, ceilings, and columns
• Most affordable and versatile lath type

Self-furred lath has small, raised dimples or “furs” that create a 1/4-inch gap between the lath and the wall surface. This gap allows plaster to fully bond behind the lath for maximum strength.

• Superior mechanical bonding with plaster
• Prevents delamination and hollow spots
• Ideal for vertical walls and solid surfaces
• Required for many commercial building codes

Ribbed lath features integrated rigid ribs running along the sheet, adding extra stiffness and preventing sagging on ceilings and large surfaces.

• Extra rigidity for ceilings and soffits
• Resists bending and warping
• Best for large, flat surfaces
• Available in flat rib and V-rib designs

Corner bead lath is a specialized type designed to reinforce and protect wall corners, creating sharp, durable, and crack-resistant edges.

• Reinforces 90-degree internal/external corners
• Protects corners from impact damage
• Creates straight, clean plaster lines
• Essential for high-traffic areas

This ultra-flexible lath is designed for curved walls, arches, columns, and rounded architectural features. It bends easily without breaking.

• Bends to form circles and curves
• Ideal for architectural design elements
• Retains shape after bending

Types of Expanded Metal Lath (By Material)

The base metal of expanded metal lath determines corrosion resistance, durability, and suitable environment (indoor vs outdoor). Below are the most common material types.

Galvanized expanded metal lath is the industry standard for nearly all exterior and high-moisture applications. Stainless steel is required for coastal, pool, or chemical-exposed buildings.

Types of Expanded Metal Lath (By Gauge / Thickness)

Expanded metal lath is classified by gauge (thickness). Thicker lath provides more strength but is less flexible. All types follow standard industry gauges.

• 2.5lb / 18ga Lath: Lightweight; used for interior walls, small repairs
• 3.4lb / 17ga Lath: Standard duty; most common for general construction
• 4.2lb / 16ga Lath: Heavy duty; used for exteriors, ceilings, high-stress areas

The 3.4lb expanded metal lath is the most widely specified type for residential and commercial projects, balancing strength, weight, and cost.

Specialized Types of Expanded Metal Lath

Beyond standard lath, several specialized types are engineered for unique construction challenges and applications.

A heavy-duty lath with a tighter mesh pattern, designed specifically for exterior stucco systems and EIFS (Exterior Insulation and Finish Systems).

Code-compliant lath designed for fire-rated walls and assemblies, providing structural support while meeting fire safety requirements.

Thicker, stronger lath used to reinforce brick, block, and stone masonry walls, preventing structural cracking over time.

Lath laminated with asphalt paper for moisture barrier protection, commonly used in exterior wall assemblies.

How to Choose the Right Type of Expanded Metal Lath

Selecting the correct lath depends on location (indoor/outdoor), surface type, moisture level, and building codes. Use this expert guide:

1. Exterior Walls: Use galvanized self-furred lath (3.4lb)
2. Interior Walls: Standard diamond lath (2.5–3.4lb)
3. Ceilings/Soffits: Ribbed reinforced lath
4. Wall Corners: Corner bead lath
5. Curved Walls: Flexible curve lath
6. Coastal/Marine Areas: 316 stainless steel lath
7. Commercial Buildings: Self-furred lath (code requirement)

If you need help selecting the right type of expanded metal lath, our technical team provides free product consultation and code-compliance support.

Why Choose Our Expanded Metal Lath?

With 20 years of experience in metal mesh manufacturing, we produce all types of expanded metal lath to the highest international construction standards. Here’s why builders and contractors trust us:

• Full product line: standard, self-furred, ribbed, corner, flexible, and specialized lath
• Premium materials: galvanized steel, stainless steel, aluminum, and carbon steel
• Complies with ASTM C1063 international construction standards
• Available in all gauges: 2.5lb, 3.4lb, 4.2lb
• Custom sizes and cutting services available
• Factory-direct pricing with fast global shipping
• Free technical support and installation guidance

No matter what type of expanded metal lath you need for your construction project, we deliver reliable, code-compliant, and high-performance products on time and within budget.