Pro Clima’s INTELLO PLUS and INTELLO X membranes meet and exceed AC528 requirements, which is the benchmark for humidity-dependent vapor retarders.

The INTELLO line of membranes is one of the few smart vapor retarders on the market that is both code-recognized and capable of delivering consistent performance across a range of climate conditions.

However, Pro Clima takes it one step further in their quality control, which, at 475, we believe is crucial for the long-term performance of our building envelope.

Accelerated Age Testing

In addition to meeting AC528, INTELLO PLUS is subjected to accelerated aging through the European test standard EN 1296. This test exposes the membrane to a sustained temperature of 158°F (70°C) for 24 weeks, simulating long-term thermal stress.

After aging, it is re-tested to EN ISO 12572 for vapor permeability. The results show:

• Slight reduction of vapor permeance under dry conditions, making it even more protective in winter because it becomes more vapor retarding (going into class 1 vapor retarding range)
• Stable high vapor permeability under humid conditions, ensuring assemblies can dry inward year after year

This means INTELLO PLUS and INTELLO X retain and even improve their intelligent vapor control functionality after aging in the lab. This has also been confirmed by testing of a 20-year-old product.

A Working Life Of AT LEAST 50 Years

The performance and durability of INTELLO PLUS are formally documented in its European Technical Assessment (ETA), which is similar in function to an ICC-ESR report. The ETA states:

“The verifications and assessment methods on which this European Technical Assessment is based lead to the assumption of a working life of the humidity-dependent vapour control layers INTELLO and INTELLO PLUS of at least 50 years. The indications given on the working life cannot be interpreted as a guarantee… but are to be regarded only as a means for choosing the right products in relation to the expected economically reasonable working life of the works.”
— ETA-18/1146

This is a prescriptive, test-based declaration that INTELLO PLUS is suitable for long-term installation in building assemblies.

The Proven, Tested, and Trusted Choice

INTELLO PLUS and INTELLO X do not just meet the standard—they go further. INTELLO PLUS/X are AC528-compliant, rapid age stress-tested, and carry a declared working life of at least 50 years per its ETA. If long-term performance is part of your design intent, INTELLO is the solution for all your smart vapor retarding challenges.

Explore 20 Years of INTELLO in the Field →
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