Absoft van insulation for soundproofing and thermal insulation installed inside a van

The Complete Guide to Campervan Insulation (2025)

Best Materials, Installation Methods & Expert Tips for UK Van Conversions

Insulating a campervan properly is one of the most important steps in any conversion project. Whether you’re creating a weekend getaway vehicle or a full-time mobile home, the right insulation materials determine how warm, quiet and energy-efficient your van will be. Poor insulation leads to condensation, heat loss, damp, mould, and uncomfortable temperature swings throughout the year.

This extended guide covers the best insulation materials, how to install them, what to avoid, and provides specific product recommendations from CampervanInsulation.co.uk — the UK’s specialist supplier of automotive-grade insulation.


Why Campervan Insulation Matters

1. Temperature Control All Year Round

The UK climate can bring cold winters, humid springs, and increasingly hot summers. Insulation creates a stable interior environment by:

  • Retaining warmth during winter

  • Reflecting external heat during summer

  • Reducing reliance on heaters and fans

  • Lowering battery usage for off-grid living

2. Condensation Prevention

Metal van walls attract moisture. Without proper insulation, warm air meets cold metal, forming condensation that leads to:

  • Rust

  • Mould

  • Corrosion

  • Damp smells

  • Wet bedding and upholstery

Closed-cell foam is the best solution because it does not absorb water, unlike wool or open-cell foam.

3. Noise Reduction

Driving can be noisy, especially in uninsulated vans. The right acoustic materials reduce:

  • Road noise

  • Tyre rumble

  • Vibrations

  • Panel resonance

  • Rain noise

  • Engine hum

Sound deadening + closed-cell foam = the quietest campervan setup.

The Best Campervan Insulation Materials (Explained)

Below are the most effective insulation materials used in UK van conversions today — including recommended products available at CampervanInsulation.co.uk.

1. Closed-Cell Foam (Top Recommended)

Best for: Walls, floors, ceiling, doors, wheel arches.

Closed-cell foam is the number-one choice because it is:

  • Moisture-resistant

  • Lightweight

  • Flexible

  • Thermally efficient

  • Excellent at absorbing sound

  • Easy to install with self-adhesive backing

Recommended products:

  • GMXR Closed Cell Foam Rolls (5mm–10mm)

  • GlassMAT GR Foil-Backed Foam (8–10mm)

  • GlassMAT ZR Heavy-Duty 30mm Foam

  • Self-Adhesive Van Liner Foam Sheets (8mm–10mm)

These materials are automotive-grade, fire-tested, and designed specifically for van conversions.

2. Foil-Backed Thermal Insulation

Best for: Roofs, side walls, areas exposed to radiant heat.

Foil insulation improves thermal efficiency by reflecting radiant heat away from the van in hot conditions and back into the vehicle in winter. It also acts as an effective vapour barrier when properly taped and sealed.

Popular products:

  • GlassMAT GR Aluminium-Backed Foam

  • SOShield All in One Thermo Van Liner 10mm Rolls

  • Heat Reflective Foil Insulation Layers

Foil-backed insulation is particularly valuable in a metal vehicle due to rapid heat transfer through steel panels.

3. PeaceMAT XR Professional Sound Deadening Mats (First Layer for Noise Control)

Best for: Floors, wheel arches, inside doors, under seats.

Sound deadening mats eliminate vibration, panel flex, and “tin can” noise. They provide the biggest improvement in road noise when applied before insulation.

Popular products:

  • PeaceMAT™ XR Audio Deadening Sheets

  • Butyl Sound Deadening Mats (various sizes)

  • High-Temperature Engine Bay Soundproofing Mats

Typically, covering 20–30% of each large metal panel gives optimum noise reduction.

4. Absoft 25mm Recycled Plastic Loft Insulation (Secondary Layer)

van fleece insulation

Best for: Filling deep cavities behind walls (only when kept dry).

Polyester-based insulation (recycled plastic fleece) is:

  • Non-itch

  • Lightweight

  • Sustainable

  • Effective at absorbing sound

Product available:

  • 25mm Van Fleece Recycled Plastic Camper Insulation

Important: never place this directly against bare metal, as it may trap moisture. Always use closed-cell foam as the moisture-blocking first layer.

5. GlassMAT HTX Engine Bay & High-Temperature Insulation

Camper Van Under Bonnet Fire Retardant Thermal Insulation Glassmat HTX 10mm

Best for: Campervan hoods, bulkheads, firewalls, engine compartments.

These products withstand extreme temperatures while blocking noise and heat transfer.

Recommended material:

  • GMHTX High-Temperature Engine Bay Insulation Sheets (up to 180°C)

Essential for campers with front-engine heat exposure.

Where to Install Insulation in a Campervan

To fully optimise thermal and acoustic performance, insulate:

  1. Roof/Ceiling – major heat loss area

  2. Walls – regulate temperature and block road noise

  3. Floor – prevents cold rising from underneath

  4. Wheel arches – one of the noisiest parts of the vehicle

  5. Cab doors & rear doors – often overlooked but critical

  6. Bulkhead (if kept) – reduces engine heat and sound

  7. Sloping roof sections & pillars – improve consistency

How Much Insulation Do You Need?

Small vans (Caddy, Berlingo, NV200)

10–15 m²

Medium vans (VW T5/T6, Transit Custom, Vito)

15–20 m²

Large vans (Sprinter, Crafter, Ducato L3/L4)

20–30 m²+

Sound deadening usually requires just 20–30% surface coverage, while thermal insulation requires full coverage.

Step-By-Step Installation Guide

Step 1: Apply Sound Deadening Mats

Reduce vibrations and resonance. Focus on:

  • Wheel arches

  • Doors

  • Floors

  • Large metal panels

Step 2: Install Closed-Cell Foam

Self-adhesive sheets are easiest. Cut, peel and stick.

Use:

  • 5mm–10mm for walls and ceilings

  • 20mm–30mm for floor sections or extreme thermal needs

Step 3: Add Foil Layer (Optional but Recommended)

Foil tape all seams for an airtight vapour barrier.

Step 4: Add Secondary Loft Fleece if Required

Only in deep cavities and never directly on metal.

Step 5: Reinstall Floor, Ply Lining & Finish Panels

Understanding Thickness Variation in Foam

Closed-cell foam is pressure-formed, so thickness naturally varies. For example, 10mm foam may measure 8–10mm, and 30mm foam may measure 25–30mm.
This is normal and does not affect performance.

Once installed and allowed to relax, the foam returns toward its intended thickness.

Common Insulation Mistakes to Avoid

  • Using fibreglass wool (holds moisture and causes rust)

  • Using aluminium bubble wrap alone (poor insulation)

  • Filling cavities with expandable foam (hard to control, traps moisture)

  • Overcompressing insulation, reducing thermal performance

  • Forgetting to insulate wheel arches

  • Skipping a vapour barrier on cold surfaces

  • Using non-automotive materials (not fire tested)

Recommended Products from CampervanInsulation.co.uk

Closed-Cell Foam Rolls

  • 5mm

  • 8mm

  • 10mm

  • 20mm

  • 30mm (GlassMAT ZR)

Foil-Backed Insulation

  • GlassMAT GR Foil-Backed Foam

  • Thermo Liner Foil-Faced Rolls

Sound Deadening

  • PeaceMAT™ XR Butyl Deadening Sheets

  • Engine Bay High-Temperature Mats

Specialist Products

  • Recycled Plastic Van Fleece

  • High-Temperature GMHTX 180°C Insulation

  • Vapour Barriers & Foil Tapes

  • Adhesive-backed CCF Tiles

Final Thoughts: Build a Warmer, Quieter Campervan

Insulating your campervan correctly transforms your vehicle into a comfortable, quiet, and energy-efficient space — essential for UK travel and long-term use.

Using professional, automotive-grade materials ensures:

  • Better temperature control

  • Reduced condensation

  • Superior noise reduction

  • Longer lifespan of your build

  • Safer, more durable installations

Explore the full range of insulation materials at:

👉 www.campervaninsulation.co.uk

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