3.4 Expanded Metal Lath: Specifications, Uses & Full Guide
ANPING METAL MESH – Professional 3.4 Expanded Metal Lath Manufacturer
3.4 expanded metal lath is one of the most widely used and industry-standard stucco and plaster reinforcement meshes in North America, commercial construction, and residential building projects. If you’re searching for this exact product, you need clear details about its size, meaning, specs, installation, and where to buy high-quality versions.
As a professional metal mesh manufacturing company with 20+ years of experience, we produce premium 3.4 expanded metal lath that meets ASTM standards for stucco, plaster, concrete, and exterior insulation systems. In this complete guide, we explain everything you need to know.
What Is 3.4 Expanded Metal Lath?
3.4 expanded metal lath is a ribbed, galvanized steel expanded metal lath defined by its diamond opening size: the long way of diamond (LWD) is 3/4 inch and the short way of diamond (SWD) is 3/16 inch – commonly labeled as 3.4 pattern in the construction industry.
It is the standard weight expanded metal lath used for most exterior stucco walls, interior plaster, masonry reinforcement, and EIFS systems. The number “3.4” refers to the traditional industry sizing code for this specific diamond grid configuration.
This lath is lightweight, rigid, and provides exceptional mechanical locking for mortar – making it the top choice for professional plasterers and contractors.
Full Specifications of 3.4 Expanded Metal Lath
Below are the official, industry-standard specifications for 3.4 expanded metal lath used in US and international construction:
| Item | Standard Value |
|---|---|
| Product Name | 3.4 Expanded Metal Lath |
| Diamond Pattern | 3.4 Pattern (Standard) |
| LWD (Long Diamond) | 3/4" (19.05mm) |
| SWD (Short Diamond) | 3/16" (4.76mm) |
| Material | Hot-Dip Galvanized Steel |
| Thickness | 0.5mm (20 GA) |
| Standard Sheet Size | 4'×8' (1220×2440mm) |
| Weight | ~2.5 lbs per square foot |
| Surface | Ribbed (Self-Furring) |
| Standard | ASTM C847 |
These specs make 3.4 lath the most balanced, versatile, and cost-effective reinforcement mesh available.
Key Features of 3.4 Expanded Metal Lath
3.4 expanded metal lath stands out from other lath types thanks to these design advantages:
- Self-Furring Ribs: Creates a 1/4" gap behind the lath for full mortar encapsulation
- Strong Diamond Lock: Mortar penetrates and locks tightly into the 3.4 pattern
- Lightweight & Flexible: Easy to bend around arches, columns, and curved walls
- Galvanized Corrosion Resistance: Prevents rust for long-term exterior use
- High Tensile Strength: Prevents stucco cracking, shrinking, and delamination
- Easy Installation: Simple to cut, staple, and fasten to wood or steel studs
Primary Uses of 3.4 Expanded Metal Lath
3.4 expanded metal lath is the universal choice for these critical construction applications:
• Exterior Stucco Walls (Residential & Commercial)
The #1 use for 3.4 lath – meets building codes for stucco systems.
• Interior Plaster Walls & Ceilings
Creates smooth, durable, crack-free interior finishes.
• EIFS / Exterior Insulation Finish Systems
Reinforces insulation and base coat layers.
• Masonry & Concrete Repair
Strengthens damaged walls, columns, and concrete surfaces.
• Fire-Resistant Assemblies
Used as a base for fireproofing coatings.
• Underlayment for Tile & Stone
Provides stable reinforcement for wet areas.
3.4 Expanded Metal Lath vs. Other Lath Types
Understanding the difference helps you confirm you’re using the right product:
| Lath Type | Pattern | Best For |
|---|---|---|
| 3.4 Expanded Lath | Standard 3/4" x 3/16" | All stucco/plaster (most common) |
| 2.5 Expanded Lath | Smaller diamond | Thin plaster |
| Flat Rib Lath | Wide ribbed | Ceilings & long spans |
| Wire Mesh Lath | Woven square | Light repairs |
3.4 expanded metal lath is the default choice for 90% of all stucco and plaster projects.
Installation Basics for 3.4 Expanded Metal Lath
Professional installation follows these simple steps:
- Attach lath to studs with galvanized staples or screws
- Overlap sheets 1 inch vertically and horizontally
- Ensure ribs face outward for proper mortar penetration
- Apply scratch coat, brown coat, and finish coat over lath
Always follow local building codes and ASTM C847 standards for best results.
Frequently Asked Questions: 3.4 Expanded Metal Lath
What does “3.4” mean in 3.4 expanded metal lath?
Is 3.4 lath galvanized?
What size is 3.4 expanded metal lath?
Can 3.4 lath be used for ceilings?
Is 3.4 lath self-furring?
Where can I buy high-quality 3.4 expanded metal lath?
Why Choose Our 3.4 Expanded Metal Lath
We are a trusted manufacturer for contractors, distributors, and construction companies worldwide:
1. Strict ASTM C847 Compliance
Meets all North American and international building code requirements.
2. Premium Hot-Dip Galvanized Coating
Superior rust protection for long service life.
3. Precise 3.4 Diamond Pattern
Consistent sizing ensures strong mortar bonding.
4. Factory-Direct Wholesale Pricing
Low expanded metal mesh wholesale price for bulk orders.
5. Fast Global Shipping
From our certified Anping expanded metal factory to ports worldwide.
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ASTM standard | galvanized | 4'×8' sheets | wholesale price | free sample available
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