HIGH - RISE AIRTIGHT & FIRE PROTECTION SYSTEM
Passive Purple® + FRED — Intelligent Membrane System
Passive Purple & FRED, when combined, create a cutting-edge fire-retardant and airtight vapor control system engineered for maximum performance. Designed for demanding construction projects, from Passivhaus builds to high-rise developments, this innovative solution delivers exceptional fire resistance, superior airtightness, and advanced vapor control. As a Class B High-Rise Airtight & Fire Protection System, it meets the strict requirements of tall buildings.
Features
- Fire Class B Certified (EN 13501-1)
when used together - Superior Fire Retardancy &
Intumescent Properties
- Resistant to Radon Gas &
High Temperatures
- Strong Adhesion to Multiple
Substrates - Meeting Passivhaus, EnerPHit, and
High-rise Building Regulations
How the Passive Purple + FRED system works
Airtightness and fire safety are usually specified as two separate packages. This system puts them in one liquid-applied build-up, applied in two stages.
Stage 1 – the airtight layer: Passive Purple
Passive Purple is sprayed, rolled or brushed onto the substrate to form a seamless airtight and vapor-control membrane. On its own it is classified Euroclass C-s1,d0 to EN 13501-1: very low smoke (s1) and no flaming droplets (d0).
Stage 2 – the fire upgrade: FRED
Once Passive Purple is dry, FRED, a white intumescent fire-protection topcoat, is applied over it. Together the two coatings are classified Euroclass B-s1,d0.
What the Class B classification covers
- Classified to EN 13501-1 by PAVUS a.s. (Czech Republic, Notified Body 1391), report reference PK1-01-25-014.
- Valid on A1 substrates with a density of 653 kg/m³ or more.
- The B-s1,d0 classification belongs to the Passive Purple + FRED system. Passive Purple alone is C-s1,d0.
Where the system is used
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High-rise and cladding remediation
See the high-rise systemWhen old cladding is stripped, the system is sprayed onto the exposed backing wall from the scaffold. That makes the envelope airtight and lifts the face of the wall to Class B-s1,d0 without entering occupied flats.
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Passivhaus and EnerPHit
Passive Purple fire performance explainedPassive Purple gives the continuous airtight and vapor-control layer that Passivhaus and EnerPHit targets depend on. FRED is added where the specification also calls for a higher reaction-to-fire class.
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Timber frame and spray foam
Fire protection for timber frame and spray foamFRED is also used as a fire-protection topcoat over timber and spray foam insulation, and has been tested on a load-bearing timber frame panel.
Common questions
Is Passive Purple fire rated on its own?
Yes. Passive Purple alone is Euroclass C-s1,d0. FRED is what lifts the build-up to Class B.
When do I need FRED?
When the specification asks for a higher reaction-to-fire class than C-s1,d0, for example on high-rise facades and cladding remediation.
When is FRED applied?
After the Passive Purple membrane has dried. Follow the FRED install guide below for preparation, coverage and drying times.
Can you help with my specification?
Yes. Send us your drawings and the technical team will mark up the airtight and fire-protection details for you.
Technical documents
- Reaction to fire classification – Passive Purple + FRED (B-s1,d0)
- Reaction to fire classification – FRED (A2-s1,d0)
- Fire resistance report – FRED on a load-bearing timber frame panel
- FRED product sheet
- FRED install guide
- FRED safety data sheet
- FRED specification clause (07 81 23)
More reading: Intumescent paint explained · Spray foam fire protection with FRED · All technical details