Category: Van Conversion- Insulation

Campervan insulation is the one part of a conversion you cannot fix later without pulling everything apart. Once the cabinets, bed and wiring go in, the walls are closed for good.

This plan covers the build order, what Australian touring asks of a van, the heat sources builders forget and how to choose a kit. For the panel-by-panel method, read the van insulation guide. For materials, go to the Kool Wrap van insulation range.

Why campervan insulation comes first

• You only get bare metal once. Every panel, rib and cavity is open before the fit-out starts.
• Everything else sits on top of it. Wiring, lining, cabinets and the bed all fix over or through the insulated walls.
• It sets your comfort for the life of the van. A well-insulated camper holds heat on a cold night and resists it on a hot one, so your heater and fans work less. That matters when you are running off batteries and solar.
• Sound deadening goes straight onto bare steel. You cannot add it properly once the lining is up.

How to fit out a campervan, in order

1. Strip. Remove the lining panels, floor covering, door cards and anything you do not plan to keep.
2. Treat rust. Sand back, treat and paint any rust, especially around the floor, wheel arches and door sills. Seal holes left by old fittings.
3. Cut openings. Fit windows, the roof fan, vents and cable entries now, before any material covers the metal.
4. Sound deadening. Self-adhesive sound deadener goes on 100 per cent of the floor and about 20 to 30 per cent of the side and ceiling panels, centred on each panel. How much a van needs has the arithmetic.
5. Insulation. 10mm foil-faced Van Liner over the walls and ceiling, with every join taped. Floor insulation or underlay over the floor deadener.
6. Wiring runs. Run 12V cable and solar leads along the ribs over the insulation. Use grommets or conduit wherever cable passes through metal. Have a licensed electrician do any 240V work.
7. Lining. Fit ply, lining board or carpet-lined panels. Photograph each wall before you close it up so you know where every cable runs.
8. Fit-out. Floor covering, cabinets, bed, kitchen and water go in last.

Steps 1 to 5 are the ones with a deadline. After step 6 the walls start closing.

Planning for Australian conditions

A single lap can hit both extremes. A summer run through the north puts your roof in direct sun all day. A winter night in the high country goes the other way.

Heat

The roof and the sun-facing walls take the most sun. Give the roof full Van Liner coverage and keep the foil face continuous with taped joins, because a gap in the face is a gap in the barrier. Park in shade where you can and run the roof vent to push hot air out of the top of the van.

Cold

Heat escapes through every gap and every bare rib. Line the rear and sliding doors as well as the walls, and cover exposed ribs where you can. Windows lose heat fast, so plan for insulated window covers.

Condensation

Cold nights, two people breathing and a closed van add up to moisture on every cold surface. Closed-cell foam with a foil face, taped joins and a roof vent keep it off the steel. Van Liner helps prevent condensation, but only where the barrier is unbroken.

For an extra reflective layer behind lining panels, foil bubble insulation is waterproof and blocks up to 95 per cent of radiant heat. Tape its joins too.

Two heat sources builders forget

Inside insulation is only half the plan. Two heat sources come from outside the living space and need their own fix.

Diesel heater exhaust

A diesel heater is a common way to heat a camper on a cold night. Its exhaust pipe gets hot, and in a tight build it often runs near cupboards, timber, cables or the floor. Wrap it. The diesel heater exhaust insulation kit includes 4.5m of 25mm wrap and four stainless steel ties, made for heaters sitting near cupboards in caravans and campers. Our guide on how to insulate diesel heater exhaust pipes walks through the fit. Follow the heater maker’s instructions for exhaust routing and clearances.

The exhaust under your floor

In a van the vehicle exhaust runs under your living space. On a long, hot run the floor above it heats up, and so does anything stored on it. Stick a 5mm heavy duty adhesive heat shield to the underside of the floor pan above the pipe, never onto the pipe itself. Our 4WD and touring heat protection page covers hot floors and other touring heat problems.

Gear list

Materials

• Sound deadener sheets and a roller applicator
• 10mm Van Liner
• 50mm aluminium foil tape
• Floor insulation or underlay and a ply subfloor
• A 5mm heavy duty heat shield, if the exhaust runs under the floor
• A diesel heater exhaust insulation kit, if you are fitting a diesel heater

Tools

• Trim removal tools, a drill and hole saws for vents and cable entries
• Rust treatment and paint
• Wax and grease remover and lint-free cloths
• Scissors, utility knife, tape measure and cardboard for templates
• Gloves and a head torch

Choosing a kit

Kool Wrap van kits bundle sound deadener, 10mm Van Liner and a free roller, sized by wheelbase and roof height. Kit #1 suits a small van or 4WD. Kits #2 to #6 cover standard, long and extra long wheelbase vans with low, medium and high roofs. Two of them carry the same material for different body shapes, so match the deadener and liner figures to your own measurements rather than assuming a higher kit number means more material. You cut the material to fit, and the kits suit most vans, including the Toyota HiAce, Ford Transit, Mercedes Sprinter and Renault Trafic.

Measure your wall and ceiling area first, then match it to the kit table in the van insulation guide. If you only need extra deadener for doors or arches, buy it in sheet packs.

Mistakes to avoid

• Fitting cabinets or wiring before insulation. You will never get behind them again.
• Cutting window and vent holes after insulating. You tear the foil and leave gaps.
• Sealing rust in. It keeps spreading behind the lining.
• Treating heat only from the inside. Underfloor exhaust heat and a hot heater exhaust need their own fixes.
• Leaving joins untaped. Condensation forms behind the lining.
• Skipping ventilation. A sealed, well-insulated van still needs air flow.
• Closing walls without a record. Photos of your cable runs save hours later.

Campervan conversion questions

What is the difference between a campervan and a motorhome?

A campervan is a van converted inside its original body, so it drives and parks like a van. A motorhome is built on a truck or bus chassis with a purpose-built living body, so it is larger inside and larger everywhere else. The insulation job is the same in principle. A converted van just has more curves, ribs and awkward corners to work around, which is why self-adhesive material suits it.

How do you stay warm in a campervan?

Insulate before you heat. Full Van Liner coverage on the roof and walls, taped joins, lined doors and insulated window covers all reduce how hard the heater has to work. Then add the heat source, and wrap its exhaust. A camper that loses heat as fast as the heater makes it will run the battery flat trying.

How much does it cost to convert a campervan?

It depends almost entirely on the fit-out, the van and how much of the work you do yourself, and Kool Wrap does not publish build budgets. What is worth knowing is that insulation is a small and predictable share of the total, and it is the only part you cannot go back and redo. Get it right first and the rest of the budget is yours to move around.

How does a diesel heater work in a campervan?

It burns a small amount of diesel in a sealed combustion chamber, blows cabin air across a heat exchanger and sends the exhaust gases outside through a pipe under the van. The combustion side is meant to stay sealed from the living space, and that depends on the exhaust staying sealed too, so check the joints and clamps as part of your servicing and fit a carbon monoxide alarm in the living space. The part that matters for your build is that the exhaust pipe runs hot and often close to timber and cables, so it needs wrapping. Follow the heater maker’s instructions for routing and clearances.

Can you insulate a campervan in stages?

The metal work cannot be staged. Deadener and liner both need bare panels, so they go on in one pass before anything closes up. Window covers, floor coverings and extra reflective layers behind lining panels can wait.

Is campervan roof insulation different from the walls?

Same materials, more of them, and it matters more. The roof takes direct sun all day, so it gets full Van Liner coverage rather than partial, and every join up there gets taped. It is also the hardest surface to work on, so cut the liner into lengths of about a metre and get a second pair of hands.

Ready to start your build?

Pick your kit from the Kool Wrap van insulation range. Not sure which size fits? Call 1300 44 33 34 with your van’s make, wheelbase and roof height and we will help you plan it.

A bare steel van is an oven in summer, a fridge in winter and a drum on corrugated roads. Van insulation fixes all three, and it does it with two layers fitted in the right order.

This guide takes you through the job panel by panel, using the Kool Wrap van insulation range. Self-adhesive sound deadener goes on the bare metal. Then 10mm foil-faced Van Liner goes over it. Both are peel and stick, so you need no spray adhesive and no mechanical fixings.

Plan the job before you peel anything

• Strip the van back to bare metal. Remove the wall and roof lining panels, floor covering, door cards and any old insulation. Bag and label the trim clips as you go.
• Check for rust. Treat and seal it now, because you will not see it again once the panels are lined.
• Clean every surface you plan to cover. Use wax and grease remover or isopropyl alcohol on a lint-free cloth. Adhesive will not hold on dust, oil or silicone residue.
• Map your openings. Mark where the roof fan, windows, solar cable entry and cabinet mounts will go so you do not bury them.
• Pick a dry, mild day. Self-adhesive products grip best on a clean, dry panel at room temperature.

The layer order that works

Every panel gets the same system, from the metal inwards.

1. Sound deadener on the metal. These high-mass sheets measure 50 x 32cm, sit around 2mm thick, weigh 3kg per square metre and carry an aluminium top layer. The mass stops thin steel from ringing.
2. Van Liner over the deadener. It is 10mm closed-cell foam with a foil face and a pressure sensitive adhesive back. It keeps the van warmer in winter and cooler in summer, reduces noise and helps prevent condensation.
3. Aluminium foil tape over every join. Taped seams keep the foil face continuous and stop moist air reaching cold metal.
4. Your lining panels. Ply, lining board or carpet-lined panels go on last, after the wiring.

You do not need deadener on every square centimetre. Kool Wrap kit guidance is 100 per cent of the floor, then smaller sections in the centre of the side panels and ceiling, covering about 20 to 30 per cent of those panels. The centre of a flat panel vibrates most, so that is where the mass earns its place. How much sound deadening a van needs goes into that in detail.

Each 50 x 32cm sheet covers 0.16 square metres. Divide the area you want to treat by 0.16 to get your sheet count. Buy car and van sound deadener in packs of 4, 12 or 24 sheets, and seal joins with aluminium foil tape.

Tools and materials

• Trim removal tools and a socket set
• Wax and grease remover or isopropyl alcohol, plus lint-free cloths
• Sharp scissors and a utility knife
• A roller applicator to press the deadener down
• Tape measure, marker and cardboard for templates
• 50mm aluminium foil tape
• Gloves and a head torch

Walls step by step

1. Knock on each panel with your knuckle. The spots that boom are where the deadener goes first.
2. Cut deadener pieces to fit between the ribs, centred on each large panel. Aim for about 20 to 30 per cent of the panel area.
3. Peel the backing and place the piece. Roll it firmly from the centre out until it sits flat with no air pockets.
4. Make a cardboard template for each wall section, including ribs, handles and openings.
5. Trace the template onto the Van Liner and cut it with scissors.
6. Peel and stick the liner from the top edge down. Press it into the ribs and around curves. The foam contours to curved surfaces, so work it in with your palm.
7. Tape every join and cut edge with aluminium foil tape.

Van roof insulation step by step

The roof takes the most direct sun, so it is the priority for heat.

1. Cut and fit the roof fan, vents and solar cable glands first. Cutting through insulation later tears the foil and leaves gaps.
2. Apply deadener to the centre of each roof panel between the roof bows. Again, aim for about 20 to 30 per cent of the area.
3. Cut the Van Liner into lengths of about a metre so you can handle it overhead.
4. Peel back the first part of the backing, fix that edge, then peel and press as you go. A second pair of hands helps.
5. Press the liner up into the roof bows so no air pocket is left behind it.
6. Tape every join and the edges around the vent openings.

Floor

The floor carries tyre, road and exhaust noise, so it gets full coverage.

1. Cover 100 per cent of the floor with deadener. Butt the sheets together and roll each one down hard.
2. Lay your floor insulation or underlay over the deadener.
3. Fit the subfloor, usually ply, then your floor covering.

If the exhaust runs close under the floor, fix that heat at the source. Stick a 5mm heavy duty adhesive heat shield to the underside of the floor pan above the pipe. Kool Wrap recommends this heavier 0.25mm foil version for under-car jobs where the exhaust heats the floor. Stick it to the floor pan only, never onto the exhaust itself.

Wheel arches and doors

Wheel arches sit right above the tyres and pass a lot of road noise into the van. Cover the arch tops fully with deadener, line over them with Van Liner and tape the edges.

• Remove the door card and any plastic moisture sheet.
• Stick deadener to the inside of the outer skin through the access holes.
• Keep clear of window regulators, lock rods, cables and the drain holes along the bottom of the door.
• Line the inner frame with Van Liner, then refit the door card.

Van insulation for hot weather

An Australian summer works on the van from above. The roof sits in direct sun all day and radiates that heat down into the living space, so the roof is where the effort goes.

• Give the roof full Van Liner coverage. Keep the foil face continuous, because a gap in the face is a gap in the barrier.
• Tape every join on the roof, not just the obvious ones.
• Keep air moving. A roof vent pushes hot air out of the top of the van, which is where it collects.
• Park nose-in to the sun where you can, so the long sun-facing wall is in its own shadow.

For an extra reflective layer behind your lining panels, foil bubble insulation is waterproof and blocks up to 95 per cent of radiant heat. Tape its joins as well.

Stopping condensation

Condensation forms when warm, moist air from breathing, cooking and wet gear meets cold steel. Two things stop it.

• A continuous barrier. Van Liner is closed-cell foam with a foil face, and taped joins keep moist air off the metal. The barrier only works where it is unbroken, which is why van roof insulation to stop condensation is mostly a taping job.
• Ventilation. Run a roof vent or crack a window, especially when you cook or sleep.

Which kit suits your van

Every Kool Wrap van kit includes sound deadener, 10mm Van Liner and a free roller. You cut the material to fit, and the kits suit most vans, including the Toyota HiAce, Ford Transit, Mercedes Sprinter and Renault Trafic.

Building a camper rather than lining a work van? Our campervan conversion insulation plan sets out the build order from stripping the van to fitting cabinets.

Common mistakes

• Sticking onto dusty or oily metal. The adhesive lets go in the first hot spell.
• Covering whole wall panels in deadener. You add weight for little return. The centre of each panel does the work.
• Leaving joins untaped. Each gap lets moist air reach the steel.
• Blocking drain holes, factory vents or door mechanisms.
• Covering rust instead of treating it.
• Skipping ventilation.

Van insulation questions

How long does it take to insulate a van?

Plan on at least a full weekend for a small or medium van, and longer for a long-wheelbase high roof. Stripping the trim, treating rust and cleaning the panels usually take longer than sticking the material on.

How do you insulate a van for winter?

The same two layers do the winter job as the summer one, but the detail work matters more. Line the rear and sliding doors as well as the walls, cover exposed ribs where you can and tape every join, because heat leaves through gaps. Windows lose heat fastest, so plan for insulated window covers as well.

What is the best insulation for a van conversion?

A self-adhesive system, because a van is all curves, ribs and awkward corners. Kool Wrap uses sound deadener on the bare metal and 10mm foil-faced Van Liner over it. Both peel and stick, the liner contours to curved surfaces, and you cut both with scissors.

Do you need sound deadening as well as insulation?

In a van, yes. They do different jobs. The deadener is high-mass sheet that stops thin steel panels ringing. The Van Liner is foam with a foil face that handles heat, cold and condensation. Fitting the liner without the deadener leaves you with a quiet-looking van that still drums on a corrugated road.

Can you insulate a van without stripping the lining?

You can add material to what is exposed, but you cannot do the job properly. Sound deadener has to go on bare metal, and a foil barrier only works if it is continuous, which means reaching the panels behind the lining. If the van is already lined, budget the time to take it out.

Does van insulation need an air gap behind it?

The Van Liner goes straight onto the panel, or onto the deadener where you have fitted it. It is 10mm closed-cell foam with a foil face and a pressure sensitive adhesive back, and it is designed to stick to the surface it is protecting. The ribs and the lining battens leave a cavity in front of it anyway, so there is nothing to build. What matters more is that the joins are taped, because a gap in the foil face is a gap in the barrier.

Need help choosing?

Measure your walls and ceiling, note your wheelbase and roof height, then pick your kit from the Kool Wrap van insulation range. If your van sits between two sizes, call 1300 44 33 34 and we will help you work out what you need.