Fire Treated Wood vs Pressure Treated Wood: Key Differences
They may sound similar, but fire treated wood and pressure treated wood serve very different purposes. Choosing the wrong one for your project could be a costly mistake.
The Basics
| Feature | Fire Treated Wood (FRTW) | Pressure Treated Wood (PTW) |
|---|---|---|
| Purpose | Fire resistance | Rot and insect resistance |
| Treatment | Fire-retardant chemicals | Fungicides and insecticides |
| Typical Use | Above-ground framing, walls, roofs | Decks, fencing, ground contact |
| Code Compliance | IBC, NFPA standards | Depends on application |
Fire Treated Wood (FRTW)
- Treated to slow flame spread
- Used in code-restricted areas (e.g., corridors, stairways, exteriors)
- Reduces smoke generation and structural damage in fire conditions
- Not intended for permanent contact with soil or direct long term exposure to the outside elements.
Pressure Treated Wood (PTW)
- Treated to resist decay, fungus, and insect damage
- Ideal for outdoor and below-grade applications
- Not designed to resist fire or reduce flammability
- Often green-tinted due to copper-based preservatives
When to Use Each
Use Fire Treated Wood when:
- You’re building in fire-restricted zones or wildfire-prone regions
- Your design must meet IBC or NFPA code standards
- Safety and compliance are top priorities
Use Pressure Treated Wood when:
- You’re building decks, posts, or retaining walls in contact with soil
- Moisture and pest resistance are key
Don’t Confuse the Two
Swapping one for the other can result in failed inspections, safety risks, or structural problems. Always specify the right material for the job—and make sure your supplier understands the difference.
Choose Biewer for Trusted Fire Treated Lumber
At FireTreatedWood.com, we provide FRTW solutions engineered for performance, reliability, and code compliance. Need help choosing the right product? Contact our team today.