KD 6 and KD 7 represent pivotal versions in the Knauf drywall product family, balancing fire resistance, acoustic control, and installation efficiency. Understanding their differences helps architects, contractors, and facility managers select the right board for each room and regulatory requirement.
This article breaks down core data, performance attributes, and real-world use cases so you can confidently integrate these boards into your next project.
| Product | Core Material | Typical Thickness | Fire Rating | Best Use Case |
|---|---|---|---|---|
| KD 6 | Gypsum core with reinforcing fibers | 12.5–15 mm | 30–60 minutes | Partitions and internal walls where light fire protection is needed |
| KD 7 | Enhanced gypsum with additives for higher strength | 15–20 mm | 60–120 minutes | High-traffic areas and commercial spaces requiring longer fire resistance |
| Installation Style | Concealed fastener system | Compatible with steel or timber frames | Passive fire protection integration | Used in systems tested to national standards |
| Acoustic Performance | Rw ~41–45 dB | Rw ~45–50 dB | Enhanced by additional insulation and airtight detailing | Higher values for speech privacy and noise reduction |
Technical Specifications and Performance Metrics
KD 6 delivers a balanced specification for standard interior partitions, with a thickness of 12.5 to 15 mm and a fire resistance up to 60 minutes when installed as tested. The core contains glass fibers that improve screw retention and crack control, making it suitable for office partitions and residential corridors.
KD 7 steps up in both thickness and performance, commonly supplied at 15 to 20 mm and offering fire ratings from 60 to 120 minutes. The enhanced formulation supports heavier loads and longer fire protection, which is valuable in high-occupancy commercial buildings and multi-story structures.
Fire Protection and Regulatory Compliance
Selecting between KD 6 and KD 7 starts with local building codes and the required fire separation times. KD 6 fits scenarios where code documents call for 30- to 60-minute fire barriers, while KD 7 aligns with stricter demands for stair enclosures, corridors, and fire-rated shaft enclosures.
When combined with proper joint treatments, fire-resistant membranes, and tested steel or timber framing, both boards integrate into certified passive fire protection systems. Always verify test reports and manufacturer installation guidelines to maintain regulatory approval.
Acoustics and Space Comfort
Sound Reduction Capabilities
KD 6 typically achieves Rw around 41–45 dB, providing adequate sound separation for light commercial and residential interiors. Adding insulation and airtight sealing improves performance, especially for speech privacy and background noise control.
Enhanced Acoustic Control with KD 7
KD 7 generally delivers Rw in the 45–50 dB range due to its increased mass and stiffness, making it preferable for open-plan offices, schools, and healthcare spaces where minimizing disturbance is critical.
Installation Best Practices and Efficiency
Both KD 6 and KD 7 are designed for concealed fastener systems, allowing screws to be placed precisely within the runner pattern. Properly aligned guides and supports reduce deflection and ensure a smooth finished surface, which is especially important in long runs and large ceiling areas.
Key Takeaways and Recommendations
- Match fire rating needs to code requirements, choosing KD 6 for moderate protection and KD 7 for extended fire separation.
- Consider acoustic targets, favoring KD 7 in environments where noise control is a priority.
- Verify compatibility with your framing system and follow manufacturer guidelines for jointing and finishing.
- Plan for service penetrations carefully to avoid compromising fire and acoustic performance.
- Use KD 7 in high-traffic, commercial, or healthcare spaces where durability and safety are critical.
FAQ
Reader questions
What fire rating can I expect from KD 6 in a 12.5 mm partition?
When installed according to the manufacturer-tested system, KD 6 at 12.5 mm typically provides up to 60 minutes of fire resistance, subject to framing type and joint detailing.
Is KD 7 suitable for use in healthcare environments?
Yes, KD 7 is commonly specified in healthcare projects because its higher thickness and fire rating support strict regulatory requirements and frequent cleaning demands.
How does acoustic performance differ between the two products?
KD 7 generally offers superior sound reduction, with Rw values around 45–50 dB, compared to KD 6 at approximately 41–45 dB, making it better for noise-sensitive spaces.
Can these boards be used in exterior applications or wet areas?
KD 6 and KD 7 are intended for interior use only; exposure to moisture or external conditions requires specific water-resistant boards and additional detailing.