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Frequently Asked Questions
What exactly is YODI™ and where does it install in the system?
YODI™ is a pre-cut, pre-sized 3-ply composite vapor barrier membrane engineered for pipe fitting insulation. It installs over the fitting insulation insert and under the PVC or metal protective jacket cover — creating a continuous, independently tested, zero-permeability seal at every elbow, tee, valve, and reducer before the finish jacket is ever applied.
Doesn’t the PVC fitting cover already act as a vapor barrier?
This is one of the most common misconceptions in the industry. PVC jacketing — including Zeston 2000 — tests at approximately 0.05 perms per ASTM E96. ASHRAE 90.1 and the mechanical insulation industry require £0.02 perms for below-ambient vapor barrier performance. PVC exceeds that threshold by 2.5x. It is a protective covering, not a vapor barrier. YODI™ tests at 0.00 perms — true zero vapor transmission.
What about vapor-sealed mastic over the PVC? Isn’t that the standard approach?
Mastic can achieve the required permeance rating — but only when applied in a precise, five-step process: surface prep, prime coat, fabric reinforcement, fill coat, and finish coat, each requiring 24–48 hours of cure time under ideal conditions. In practice, application variability, inadequate cure time, adhesion failure on plasticized PVC, and cracking from thermal cycling make mastic-over-PVC an unreliable approach. YODI™ eliminates field variability entirely — the barrier is factory-tested before it leaves the box.
What test standards back up YODI™’s performance claims?
YODI™ is independently tested and certified across multiple ASTM standards:
• 0.00 perms — ASTM E96 Method A (water vapor transmission)
• 25/50 flame/smoke — ASTM E84
• 130 PSI burst strength — ASTM D774
• 30 lb/in. tensile strength — ASTM D828
• No growth — ASTM C1338 (mold & mildew resistance)
• Class IX vapor retarder — ASTM C1136-12
All shapes are compliant with ASTM C 585-76
Is YODI™ approved by the PVC jacket manufacturers?
Yes. YODI™ meets the intermediate vapor barrier requirements of both JM Zeston PVC and Proto PVC — the two dominant protective cover systems in the North American market. It is designed to install directly beneath those covers, so your system remains fully compliant with manufacturer installation requirements and passes inspection.
What does the NIA say about vapor control at fittings?
The NIA Mechanical Insulation Design Guide, published in cooperation with ASHRAE and NIBS, identifies pipe fittings as the highest risk of vapor infiltration in any below-ambient system — and states that prefabricated, factory-tested vapor barrier materials offer more reliable performance at fittings than field-applied mastics. YODI™ was engineered in direct response to this guidance.
How does YODI™ actually install? How long does it take?
Three steps. Place the insulation insert around the fitting. Slide the pre-sized YODI™ membrane over the insulated fitting — the flexible 3-ply composite conforms to elbows, tees, valves, flanges, and reducers. Finish with your standard PVC or metal cover. No measuring, no troweling, no cure time. Installation is measured in seconds per fitting, not minutes.
What pipe sizes and fitting types does YODI™ cover?
YODI™ Covers are made for Iron Pipe sizes , copper pipe sizes as well as for grooved fittings all compliant with ASTM C 585-76 sizing standards.
What happens to insulation performance when moisture gets in?
Even a 5% moisture content by volume in mineral wool or fiberglass insulation can increase effective thermal conductivity by 20–40%. Beyond thermal degradation, moisture infiltration drives corrosion under insulation (CUI), freeze-thaw mechanical damage in refrigeration systems, mold growth in chilled water applications, and long-term energy code non-compliance. There is no self-correcting mechanism in a below-ambient system — vapor drive is always inward. A single gap at a fitting compounds continuously over the life of the system.
What systems is YODI™ designed for?
YODI™ is engineered for any below-ambient piping application where continuous vapor barrier integrity is required — including chilled water systems, dual-temperature systems, refrigeration and cryogenic piping, storm piping, and domestic cold water systems in schools, offices, high-rise residential, retail, and manufacturing facilities. It is particularly well-suited to hospitals, data centers, and process facilities where callbacks and remediation are not acceptable outcomes.