What Is Lathing in Construction?
In construction, many techniques and systems support the integrity and finish of a building. Among them, lathing stands as a vital preparatory process, especially for applications involving plaster, stucco, and other coatings. If you’ve ever seen a finely finished wall or ceiling, chances are it involved some form of lathing beneath the surface.
This article explores what lathing is in construction, its purpose, types, installation process, and its enduring relevance in both traditional and modern building methods.
🧱 What Is Lathing in Construction?
Lathing in construction refers to the process of attaching a base framework—called lath—to structural surfaces like walls or ceilings. This framework provides a gripping surface for wet finishing materials such as plaster, stucco, or veneer coatings to adhere to.
Without a lath base, these finishes would not properly bond to surfaces, resulting in poor aesthetics and reduced durability. Lathing ensures the longevity and stability of surface coatings across various construction types, from residential interiors to large-scale commercial exteriors.
🧰 Purpose of Lathing
Lathing serves multiple important roles in the construction process:
- Provides mechanical bonding for finishes like plaster and stucco
- Reinforces surface finishes and prevents cracking
- Supports fireproofing materials in wall and ceiling assemblies
- Adds rigidity to wall structures
- Assists in shaping curved or irregular surfaces
- Improves acoustic insulation in specialized assemblies
🏗️ Common Applications of Lathing
Lathing is typically used in the following construction areas:
- Interior plaster walls and ceilings
- Exterior stucco applications
- Fireproofing structural steel or framing
- Veneer stone or brick installations
- Acoustic or soundproof walls
- Historic building restorations
🔍 Types of Lath Materials Used in Construction
Lathing involves using different types of lath depending on the application. Each type offers different levels of flexibility, strength, and compatibility with finish materials.
| Lath Type | Material | Common Usage |
|---|---|---|
| Wood Lath | Thin wood strips | Historic plaster walls and ceilings |
| Expanded Metal Lath | Slit and stretched steel | Exterior stucco, fireproofing |
| Woven Wire Lath | Interlaced metal wire | Curved surfaces, light plaster |
| Gypsum Lath | Gypsum board with paper | Veneer plaster in modern interiors |
| Paper-Backed Lath | Metal with backing paper | Stucco over sheathing |
| Plastic or Vinyl Lath | PVC or polymer | High-moisture areas like bathrooms or exteriors |
🔨 Lathing Installation Process
The lathing process involves several steps to ensure the base is secure and ready for the finish layer:
- Surface Preparation
- Clean the framing or sheathing.
- Apply a water-resistant barrier if needed.
- Lath Attachment
- Secure the lath with galvanized nails, screws, or staples.
- Overlap edges by at least ½ to 1 inch for continuity.
- Furring
- Use furring strips or self-furring lath to create space behind the lath for keying.
- Accessory Installation
- Add corner beads, control joints, and weep screeds where necessary.
- Inspection
- Check for proper fastening, coverage, and alignment before applying plaster or stucco.
✅ Benefits of Lathing in Construction
| Benefit | Explanation |
|---|---|
| Improved Adhesion | Provides a textured surface for better grip of finishes |
| Structural Support | Adds strength to wall and ceiling systems |
| Durability | Prevents cracking and finish failure |
| Versatility | Suitable for flat, curved, or irregular surfaces |
| Fire Resistance | Often used in fire-rated assemblies |
| Acoustic Performance | Can help dampen sound when used in layered wall systems |
📊 Lathing vs. Drywall
| Feature | Lathing & Plaster | Drywall |
|---|---|---|
| Finish Quality | High (smooth, hard) | Moderate (taped seams) |
| Durability | Excellent | Good |
| Labor Requirement | High (more time-consuming) | Low |
| Cost | Higher | Lower |
| Custom Shapes | Easy to form | Limited flexibility |
| Soundproofing | Better with layers | Standard unless modified |
🧱 Best Practices for Lathing
- Use corrosion-resistant fasteners in exterior or wet locations.
- Always overlap metal lath to ensure continuous support.
- Install moisture barriers behind exterior lath.
- Select the correct lath type for the material being applied (plaster, stucco, veneer).
- Ensure control joints are placed correctly to allow expansion and prevent cracking.
🧠 Use of Lathing in Modern Construction
While traditional wood lath has become rare, modern construction still relies heavily on metal lath systems, especially in commercial stucco exteriors, fireproofing applications, and high-end residential plaster work. EIFS (Exterior Insulation and Finish Systems) and three-coat stucco systems both require proper lathing as a foundational step.
❓FAQs About Lathing in Construction
1. What is lathing in construction?
Lathing is the process of installing a base framework—usually metal, wood, or gypsum—on walls or ceilings to support plaster, stucco, or veneer finishes.
2. Why is lathing important?
It provides mechanical bonding, supports the finish material, prevents cracking, and contributes to fire and acoustic performance.
3. What materials are used in lathing?
Common lath materials include wood strips, expanded metal, woven wire mesh, gypsum boards, and plastic/PVC mesh.
4. Is lathing still used today?
Yes. Though drywall has largely replaced wood lath for interiors, lathing remains essential for exterior stucco, fireproofing, and high-end plaster applications.
5. Can I install lath myself?
Lathing requires knowledge of materials and spacing standards. For exterior or load-bearing applications, it’s best installed by professionals.
6. What’s the difference between wood lath and metal lath?
Wood lath is traditional, used in historical plaster systems. Metal lath is more durable and used in modern stucco, fireproofing, and commercial construction.
7. What tools are needed for lathing?
Basic tools include shears, tin snips, a hammer or screw gun, and a level. Safety gear like gloves and eye protection is also essential.
8. What are control joints in lathing?
Control joints allow the wall to expand and contract without cracking the plaster or stucco finish.
9. How much does lathing cost?
Costs vary by material and application. Metal lath systems are more expensive than gypsum board but offer greater performance.
10. Is lathing required for all plaster jobs?
Yes, in most cases. Whether it’s a small ceiling patch or an entire exterior façade, lathing ensures the material adheres securely.
Conclusion
Lathing is a crucial preparatory step in many construction applications, providing the necessary support and bonding surface for finishes like plaster, stucco, and stone veneer. Though less visible than other structural components, its impact on the quality, durability, and appearance of walls and ceilings is substantial. Whether used in a historic home or a modern commercial facade, lathing remains an integral part of high-performance construction.
