What We Mean By Permanently Airtight

What We Mean By Permanently Airtight

You may have heard us refer to a Pro Clima tape or adhesive as 'permanently airtight'. It’s important that we are clear about what we mean, because this is one of the details that sets Pro Clima tapes apart from the rest of the pack. Having an airtight layer that endures for the life of a building can depend on design decisions, such as integrating the airtight layer into the assembly, planning to include a service cavity, or choosing a caulk that flexes rather than dries up and cracks. But in the end, regardless of the design, the longevity of the materials themselves is of primary concern. Our definition of "permanent airtightness" boils down to this:

Airtight materials should be airtight for longer than the building is expected to last.

And we don't mean 30-40 year barely-code-legal homes. We mean high performance buildings: 100+ years.

Accelerated Aging Tests


Tescon Vana has been independently verified by the University of Kassel in central Germany using accelerated aging tests. What this means is that the material is exposed to extreme conditions in a controlled environment that mimic the effects of time, air, water, exposure, etc. The lab stored Tescon Vana at a temperature of 150 °F with 80 % relative humidity, sustaining it in a condition at the far extreme of what is possible for very brief periods in real construction. The tape was kept this way for 700 days, about 2 years, which demonstrates Tescon Vana's adhesion will perform reliably for 100+ years. It's important to note that the test parameters at University of Kassel were developed to determine ”quality assurance for adhesive-based joint technology in airtightness layers” - something you will uniquely find in the land of Passive House.

Real-World Testing

Floris applies Tescon INVIS tape. Tescon Vana, Tescon INVIS, and Tescon Profil tapes are the same tape, differing only by color and type of release backing.

Lab tests are correct much of the time, but long-term judgments get based on real-world use and testing. We've been using Tescon Vana in the United States since 2011, and Pro Clima developed the technology and adhesives for Tescon Vana in the early 1990's. Field tests from that time are holding strong 20 years on. The Pro Clima airtightness system has proven itself many times over, acheiving class A certification from the Passivhaus Institut (PHI) - and are among the tightest building materials tested by PHI. Solid acrylic adhesive tapes do not contain solvents - meaning no part of the adhesive is water soluble. Adhesion is pressure activated to form a strong grip at the molecular level – assuring a long lasting, durable connection between the tape and the substrate. Our real-world experience, combined with our knowledge of the material, have provided us with an unwavering confidence that this tape is the best. That's why we choose to sell it, and that's why we use it in our own projects. Want to prove it on your own? Get a sample package and test it yourself.

Longevity = Sustainability

We know there is no silver bullet to end the climate crisis. It's a billion decisions made around the world to save energy and greenhouse gas emissions. One commonality among those decisions is to stick with materials that last, rather than the ones you throw out in a few years. But even if you don't buy the environmental benefit, think of it this way: you want a hammer that will last as long as your career, not as long as your current project. And you want nails that hold the wood together as long as the wood is standing, not rust and crumble. Pick the tool that you can rely on.

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View from your Mars spacebus

Press a strip of Tescon Vana onto the plywood of new building today and you can expect it to stay airtight until 2115. We will all be cyborgs, with embedded and wearable biosensors that track physiologic metrics that are guided by one's genes and environment, you'll be worried about the housing market on the Mars colony, and Tescon Vana will still be airtight. That's what we mean by permanently airtight.