How to Install a Vapour Barrier in Your Van and Eliminate Condensation for Good

How to Install a Vapour Barrier in Your Van and Eliminate Condensation for Good

How to Install a Vapour Barrier in Your Van and Eliminate Condensation for Good

Condensation is one of the biggest challenges in van conversions. Without proper insulation and a vapour barrier, moisture can accumulate inside your van, leading to rust, mould, and interior damage. This guide will show you how to eliminate condensation for good by properly installing a vapour barrier—using high-quality materials from Car Insulation UK.


Why You Need a Vapour Barrier in Your Van

When warm air inside your van meets cold surfaces—like bare metal panels—condensation forms. Over time, this can lead to:

  • Rust and corrosion

  • Mould and mildew in insulation and wooden surfaces

  • Damp, uncomfortable interior spaces

  • Shortened lifespan of your van build

A vapour barrier stops warm, moist air from reaching cold surfaces by sealing your insulation from the inside. This is essential for a dry and long-lasting van conversion.

 

Van Thermal Insulation


Recommended Vapour Barrier Materials from Car Insulation UK

  • SOShield™ Thermal Foil Insulation

    • Double-sided reflective aluminium barrier

    • Acts as both an insulator and vapour barrier

    • Lightweight, flexible, and moisture-resistant

    • Ideal for walls, ceilings, and floors

    • Easy to cut and fit with spray adhesive or foil tape

 

  • GlassMAT™ Reflective Insulation (optional alternative)

    • Multi-layer thermal insulation

    • Excellent for thermal efficiency

    • Provides some vapour resistance when sealed correctly

 

Van Thermal Insulation


Where to Install a Vapour Barrier in Your Van

For full protection against condensation, install vapour barriers over your insulation in these areas:

  • Walls – Cover from floor to ceiling

  • Ceiling – Warm air rises, so this area is critical

  • Floor – Use SOShield™ as a thermal and moisture barrier

  • Rear doors and sliding doors – Often neglected, but essential for a full seal


Step-by-Step: How to Install a Vapour Barrier with SOShield™

Step 1: Surface Preparation
Thoroughly clean all metal surfaces. Remove rust and dirt, and seal any holes or exposed metal with rust-proof treatment.

Step 2: Install Insulation
Apply SOShield™ directly to your walls, ceiling, and floor. Use high-temperature spray adhesive or foil tape to secure it. Cut the material to size for wheel arches, cavities, and curves.

Step 3: Seal the Vapour Barrier
SOShield™ acts as both insulation and vapour barrier. Overlap edges by at least 50mm and seal all seams using aluminium foil tape. This prevents any moisture-laden air from reaching the metal surface.

Step 4: Final Layer and Finish
Once sealed, you can apply your finishing panels (plywood, carpet lining, etc.) on top. Make sure any penetrations for wiring are also sealed around with foil tape or mastic.


Extra Tips to Combat Condensation

  • Add ventilation (roof vents or window vents) to regulate airflow

  • Avoid cooking without proper extraction

  • Use moisture traps during colder months

  • Regularly air out the van to reduce humidity

Van Thermal Insulation


Conclusion

A well-installed vapour barrier using SOShield™ insulation from Car Insulation UK can make a massive difference in your van’s comfort, dryness, and long-term durability. Whether you're converting for adventure, full-time living, or occasional getaways, eliminating condensation is essential—and easier than you might think with the right materials.

Need help or product advice?
Contact Car Insulation UK today—we’re here to support your van build every step of the way.

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