Insulation is key in an Australian van build, yet many don’t get it. Mess it up, and you’ll sweat through hot days, freeze on cold nights, and fight wet walls and loud sounds on the road. Do it right, and your van becomes a cozy spot to enjoy at any time, no matter where you go.
This guide walks you through everything. If you’re new to conversion planning or looking to something fresh up, you’ll learn a clear as well as effective way of insulating your van.
1 . How Heat Travels in a Van
To choose the right insulation for your van, it’s important to understand how heat actually behaves. A well-insulated van addresses all kinds of heat transfer. Heat moves in three ways: conduction, convection, and radiation.
1.1 Conduction: Heat Through Solid Surfaces
Heat moves through solid things, like your van’s metal walls flooring and framework, by conduction.
- Example: Touch the van’s interior wall in summer—it feels hot since the sun’s heat conducted through the metal.
- What works: Install insulation materials with low thermal density, like Polyester Insulation. These create a barrier that slows the movement of heat through solid surfaces.
1.2 Convection: Heat Carried by Air Movement
Convection happens when heat moves with air flow. In a van’s wall gaps, hot air moves up, and cool air falls down, making a loop that moves heat around.
- Example: If the ribs and panels of your van are hollow and have no insulation, warm air from inside can move around and cool fast, causing loss of heat and the chance for condensation.
- What works: Fill gaps, ribs, and wall holes with insulation to stop air flow. Block these air paths to cut heat loss and keep inside temperature stay steady.
1.3 Radiation: Heat Transferred as Infrared Energy
Radiant heat is energy transmitted in the form of electromagnetic waves. It comes from the sun heating your van from the outside and from things inside like heaters that give off heat.
- Example: When sun hits your windshield or roof, it sends heat inside even if the air is cool outside. In the same way, your dashboard gets hot just from the sun.
- What works: Use foil-faced insulation or radiant barriers like Kingspan Air-cell Insulbreak to bounce heat out before it gets inside. They work well when put under roof panels or behind windows.
A good insulation setup targets all three forms of heat transfer. That’s why combining materials often works better than relying on just one.
2 . Condensation and Moisture Control
2.1 Thermal Bridges in a Van
Even with well-installed insulation, there are still places where heat can slip through.
- Structural frames and support ribs
- Door panels and metal pillars
- Areas where cabinetry or mounting hardware connects directly to the van shell
Heat takes the easiest way through. So if there’s a thick material, like steel or metal, touching both the inside and outside of your van, heat will go right through it, effectively skipping your insulation layer.
2.2 How to Minimize Thermal Bridging
You can’t remove every metal frame from your van but you can interrupt the heat path with something called a thermal break.
Kingspan Air-Cell Insulbreak: These radiant barrier products are thin, lightweight, and offer moderate compressive resistance. Placing them between metal framing and interior structures (like wall paneling or furniture) adds a layer of insulation to reduce direct heat transfer.
Avoid metal-to-metal contact: Attaching aluminum bars directly to the van’s steel body creates a thermal bridge, allowing heat to transfer easily between the materials. Use a compressible insulation layer between them to block heat flow.
2.3 Should You Use a Vapor Barrier?
Unlike homes, vans are rarely airtight. They flex when they move, temps change fast, and there are many places where leaks can happen: wiring holes, seams, and air gaps, too.
A vapor barrier might hold moisture instead of stopping it, unless your build is sealed tight, which hardly ever happens in van builds. A better approach is using breathable insulation that lets moisture escape naturally. Polyester Insulation or Thinsulate, for example, resists mold and doesn’t absorb water. Kingspan Air-Cell Insulbreak can be used on exposed metal areas to reduce heat transfer, but shouldn’t cover the entire wall, as it acts as a vapor barrier.
By letting the wall system “breathe,” you’re giving moisture a way to escape. It’s not a perfect fix, but for mobile, semi-open setups like vans, it’s usually the most practical option.
3. Best Van Insulation Materials (Reviewed & Compared)
Kingspan Air-Cell Insulbreak
Pros: Combines radiant barrier and light insulation, adds thermal break
Cons: not ideal as a standalone insulator in cold climates; requires layering with polyester insulation
Why It’s Great: Excellent for minimizing radiant heat and preventing thermal bridging, especially when layered over framing or behind wall panels.
Ideal For: Covering structural ribs, layering behind panels, thermal bridge prevention
Installation: Staple or tape in place
Cost: Moderate to high
Bottom line: A safe, eco-friendly insulation with great all-around performance—ideal for those prioritizing health, comfort, and sustainability.
Foilboard® Green Rigid Panels
Pros: High radiant heat reflection, rigid and easy to cut, includes integrated thermal break
Cons: Lower R-value compared to bulk insulation; requires precise fitting to avoid gaps
Why It’s Great: Excellent for hot climates where radiant heat is the main concern. Doubles as insulation and vapor control when installed correctly.
Ideal For: floors, ceilings, thermal bridging zones
Installation: Cut to fit and tape/seal all joints
Cost: Moderate to high
Bottom line: A strong choice for reflecting heat and adding thermal breaks, best when used with other insulation in cold or variable climates.
XPS Foam Board
Pros: High R-value, rigid structure, strong underfoot
Cons: Requires sealing at joints to prevent air and moisture leaks; not flexible for curved surfaces
Why It’s Great: Offers outstanding thermal resistance and structural support for flooring. Durable, cost-effective, and widely available.
Ideal For: Van floors
Installation: Cut to size, fill corrugations, seal joints
Cost: Affordable and widely available
Bottom line: A tough, effective insulation for floors that delivers both strength and efficiency at a budget-friendly price.
Polyester Solutions (Melbourne)
Pros: Made in Australia from recycled PET, safe to handle, breathable, non-toxic, no itch
Cons: Bulkier than other options; not ideal for tight or curved spaces
Why It’s Great: A locally made, eco-conscious insulation option with great acoustic and thermal performance. Ideal for those avoiding fiberglass or mineral wool.
Ideal For: Walls, ceilings, large cavities
Installation: Friction fit or adhesive
Cost: Moderate
Bottom line: A high-quality, Australian-made polyester insulation that’s safe, breathable, and perfect for vanlifers based in Victoria or ordering from Melbourne.
Higgins Insulation (Brisbane)
Pros: Offers a range of polyester and acoustic insulation products, locally available in Queensland, non-toxic and safe to handle
Cons: harder to fit into tight or irregular spaces
Why It’s Great: A reliable choice for thermal and acoustic comfort, especially in warmer or moderate climates. Locally made and great for van builds prioritizing health and ease of installation.
Ideal For: Walls, ceilings, acoustic zones
Installation: Cut to size or friction fit into cavities
Cost: Moderate
Bottom line: A dependable, Queensland-made insulation that balances comfort, safety, and ease of use ideal for DIY van conversions.
Other Option : Thinsulate (SM600L)
Pros: Easy to install, no mess, breathable, mold-resistant
Cons: Higher cost compared to some alternatives
Why It’s Great: Flexible, lightweight, and performs well in any climate. Excellent for tight spaces, curved panels, and moisture-prone areas.
Ideal For: Walls, ceiling, doors
Installation: Cut to size, apply spray adhesive, press into place
Cost: Moderate
Bottom line: A premium insulation option that’s reliable, DIY-friendly, and ideal for full-time vanlife in all conditions.
4. How to Insulate Each Part of Your Van
Here’s a breakdown of the best insulation ways for every part of your van interior:
4.1 Floor Insulation
The van floor is a major path for heat loss, especially in winter. However, not all insulation types are suitable here.
Recommended Material:
XPS Rigid Foam Board – Lightweight, strong, and offers high thermal resistance. It also provides a flat and stable surface for flooring.
Installation Steps:
- Fill any corrugations in the van floor with thin strips of XPS or similar material.
- Add a full layer of 1″ XPS board on top.
- Optionally, install Mass Loaded Vinyl (MLV) above the insulation for sound control.
- Overlay with ½” plywood for subflooring.
- Finish with your preferred flooring (vinyl, laminate, etc.).
XPS is cost-effective, readily available at hardware stores, and capable of withstanding pressure from foot traffic and furniture.
4.2 Walls, Ceiling, and Doors
These areas make up the majority of your van’s surface area, and insulating them effectively has the biggest impact on temperature regulation.
Recommended Materials:
- Polyester Solutions (Melbourne) – A locally made, sustainable insulation option crafted from recycled PET. It’s non-toxic, safe to handle, and provides excellent thermal and acoustic performance without any itch or chemical concerns. Great for full panel coverage and suitable for all climates.
- Higgins Insulation (Brisbane) – A high-quality polyester insulation ideal for warmer climates and builders looking for comfort and ease of use. It’s soft, safe to install without protective gear, and delivers solid thermal and sound control perfect for lining van walls and ceilings with minimal hassle.
- Thinsulate SM600L – A premium, flexible, and breathable insulation known for its ease of use and moisture resistance.
Installation Steps:
- Cut to fit using a utility knife or scissors.
- Can be friction-fit into cavities or adhered with construction adhesive or spray glue.
- Being semi-rigid and breathable, it doesn’t require a vapor barrier and is unlikely to trap moisture behind walls.
4.3 Windows
You can invest in the best insulation for your van, but if you ignore the windows, you’re missing a major heat leak. Glass is a great heat conductor—meaning it’s a terrible insulator.
You can use reflective foil covers to block the sun in warm months, but for cold camping, you’ll need something better. To keep heat in during winter, try making custom insulated window covers with Polyester Solutions or Higgins, Kingspan Air-cell and fabric layer. This mix helps a lot in freezing cold—and is key when temperature drop below -15°C (5°F).
Building a Better-Insulated Van
A properly insulated van doesn’t just feel better, it performs better. You’ll use less power to heat or cool it, stay drier and quieter, and protect your build from hidden moisture damage.
Shop quality insulation products from trusted brands like Kingspan, Polyester Solutions, Foilboard, Higgins and more at Insulation Easy Australia, a one-stop shop for DIYers, vanlifers, and pro builders across the country.
Build your insulation system to match your climate, your budget, and your travel style but always build it to last.