Caravan walls in Australia are built five common ways, and the words used to sell them are worse than useless. Stucco and alucomp are cladding. Composite might be cladding or might be the whole structure. Two brochures can use the same word for completely different walls.
This page is the engineering, in plain words. No method here is called the best one, because they trade against each other and the right answer depends on what you tow, where you take it and who will fix it. What you get instead is what each build is, what it does to the weight, how it handles heat and water, what it costs to repair, and how to read the answer off a spec sheet and off the van itself.
The one distinction that clears up most of the confusion
A caravan wall has two jobs: hold the van up, and keep the weather out. In a framed van those jobs belong to different parts. The frame holds it up, the cladding keeps weather out, and the insulation sits between the frame members. In a structural composite van, one bonded panel does all three.
So when someone says a van has composite walls, the useful follow-up is: is the composite the cladding, or is it the structure? Those are two very different caravans, and both are sold with the same word.
The five builds, side by side
Each one gets the same four questions, in the same order, so you can compare them on the things that decide the answer rather than on the things that are easiest to write brochure copy about.
Stucco aluminium over a frame
Also called: Stucco, stuco, peened or embossed aluminium cladding
A thin aluminium sheet with a dimpled finish rolled into it, fixed over a frame of aluminium or timber with insulation sitting in the cavity between the frame members. The dimples are not decorative. A flat sheet that thin shows every ripple and every knock, and the embossing scatters the light so it does not. This is the long-standing Australian caravan wall and it is still the most common thing you will walk past in a yard.
- Weight
- The cladding itself is light because the sheet is thin. The weight lives in the frame behind it and in the lining board on the inside, so two stucco vans of the same size can be a long way apart depending on what the frame is made of.
- Insulation
- Insulation is whatever fills the cavity, usually a batt or a foam block between the frame members. The frame members themselves still bridge the wall, and an aluminium frame conducts heat well, so the wall performs a bit below the rating printed on the insulation.
- Water ingress
- Water gets in at joins and at fasteners, not through the sheet. Every window, hatch, awning rail and screw is a penetration held out by sealant, and sealant is a maintenance item with a life measured in years. This is the build where an annual sealant check earns its keep.
- Repairability
- The most repairable of the lot. Panel sections can be replaced, a panel beater can work the material, and the skills are common in every town with a caravan repairer. Frame damage behind it is a bigger job because the sheet has to come off to reach it.
Words that mean this on a spec sheet: stucco aluminium, aluminium cladding, peened aluminium, meranti or alloy frame.
Alucomp aluminium composite cladding
Also called: Alucomp, alucobond, ACP, aluminium composite panel
Two thin aluminium skins bonded either side of a plastic core, sold as a flat sheet and fixed over a frame in much the same way stucco is. The sandwich makes the sheet far stiffer than a bare skin of the same weight, which is why it can be left dead flat without rippling. Read this one carefully when you shop: alucomp is usually a cladding on a framed wall rather than the structure of the wall itself, and that is the single most confused point in caravan construction.
- Weight
- Per square metre it lands close to stucco sheet, a little heavier or a little lighter depending on the core and the skin thickness. It does not change the fact that the frame behind it is carrying the load, so it rarely moves the tare much on its own.
- Insulation
- The core is thin, so on its own it adds very little. The insulation is still whatever sits in the frame cavity behind it. A flat composite skin does reflect and shed heat a bit differently to a dimpled one, but the wall build behind it is what decides the result.
- Water ingress
- Same story as stucco, with fewer joins. Larger flat sheets mean fewer seams to seal on a given wall, and the aluminium skin does not absorb water. The penetrations are still the weak point, and a damaged skin can let water sit against the core where you cannot see it.
- Repairability
- Harder than stucco and easier than a structural panel. A composite sheet cannot be beaten back into shape, so a dent usually means replacing a section, but it is still cladding on a frame and a repairer can get behind it.
Words that mean this on a spec sheet: alucomp, composite cladding, aluminium composite panel, one-piece walls.
Full composite sandwich panel
Also called: Composite panel, fibreglass sandwich, structural panel, frameless
A thick foam core bonded between two structural skins, commonly fibreglass, sometimes aluminium. The panel is the wall: it carries the load itself, so there is often no separate timber or alloy frame inside it at all. Walls, roof and floor are usually bonded to each other rather than screwed, and vans built this way are often described as one-piece or frameless.
- Weight
- For a given stiffness this is generally the lightest way to build a wall, because one component does the job that a frame, a batt, a cladding sheet and an inner lining did between them. Whether that shows up in the tare of a particular van is another question, because the chassis, suspension, water tanks and fitout usually outweigh the walls.
- Insulation
- The best of the group by a clear margin, and the reason is structural rather than clever: the foam core runs the whole way across the panel with no frame members bridging it. That continuity is worth more than the rating of any one material.
- Water ingress
- There is no timber to rot and the core does not absorb water, so a wet panel is not the emergency it is in a framed wall. The failure to know about is delamination, where water or heat breaks the bond between skin and core and the panel loses stiffness. It usually shows as a soft spot or a visible bubble.
- Repairability
- The trade-off for everything above. The panel is structural, so a serious hit is a specialist repair rather than a local panel job, and it can mean cutting out and re-bonding a section. Ask before you buy where the nearest repairer is, because this is the one build where that answer varies by state.
Words that mean this on a spec sheet: composite, sandwich panel, structural panel, frameless, fibreglass, XPS or foam core.
Timber frame
Also called: Meranti frame, timber framed walls
A timber frame, usually meranti, clad on the outside and lined on the inside, with insulation between the members. The oldest build in the Australian industry and the one nearly every repairer in the country knows how to work on.
- Weight
- Timber framing is heavier than the alloy equivalent for the same wall, and the recorded tare figures in our own catalogue back that up in general terms, though van size drives the number far more than the frame material does.
- Insulation
- Same cavity principle as any framed wall. Timber bridges heat noticeably less than aluminium does, which counts in its favour on a hot day.
- Water ingress
- The reason people ask about construction in the first place. Timber that stays wet rots, and rot in a wall frame is structural, expensive and often invisible until it is advanced. It is not inevitable, it is a consequence of water getting in and staying in, which is a sealant and maintenance question.
- Repairability
- The easiest to repair of any build here and the cheapest to have repaired, because the materials are ordinary and the skills are everywhere. A section of frame can be cut out and replaced.
Words that mean this on a spec sheet: meranti, timber frame, hardwood frame.
Fully welded frame
Also called: Welded alloy frame, welded steel frame, one-piece frame
The frame members are welded into a single structure instead of being screwed or riveted together, then clad. Aluminium and steel are both used. The point of welding is corrugations: a screwed joint can work loose over thousands of kilometres of washboard road, and a welded one cannot.
- Weight
- Depends entirely on the metal. A welded aluminium frame is in the same territory as a screwed one. A welded steel frame is heavier, and that weight buys strength, which is why it turns up under vans built for rough country.
- Insulation
- Unchanged by the welding. Insulation is still whatever fills the cavity, and metal frame members still bridge the wall.
- Water ingress
- Metal frames do not rot, which removes the timber problem entirely. Steel can corrode where the protective coating is broken, so hot-dip galvanising and how well the coating survived the build are the things worth asking about.
- Repairability
- Needs a welder rather than a screwdriver, and for aluminium it needs a welder who works in aluminium. That is a real constraint in remote areas and a non-issue in a capital city.
Words that mean this on a spec sheet: fully welded, welded alloy, hot-dip galvanised, one-piece frame.
So which one is lighter?
This is the most searched question about caravan construction and it has an unsatisfying answer: the material tells you less than you would like, and the spec sheet settles it in one number.
A full composite sandwich body is generally the lightest way to build a wall for a given stiffness, because one panel replaces a frame, a batt, a cladding sheet and an inner lining. An aluminium frame is lighter than a timber frame doing the same job. Both of those are true, and neither of them decides the weight of a caravan, because the walls are a small share of it. The chassis, the suspension, the water tanks, the batteries and the fitout usually add up to more.
Which is why a large composite van can be heavier than a small aluminium-clad one without either of them being badly built.
What the weights actually show
Group the vans by what their walls are built from and line up the published tare weights, and the spreads sit on top of each other. The wall material is a poor predictor of how heavy a van turns out to be.
| Wall build | Published tare spread |
|---|---|
| Composite | 1,920kg to 3,350kg |
| Aluminium | 2,050kg to 2,500kg |
| Sandwich panel | 1,941kg to 3,136kg |
| Timber | 2,468kg to 3,311kg |
| Fibreglass | 1,440kg to 3,060kg |
Look at the overlap rather than the order. Across every build here, published tare runs from 1,440kg to 3,350kg, and the spreads sit on top of each other. Van size and fitout move that number far more than the wall build does, which is exactly why we will not rank materials by weight off this table.
The figure that answers the question for a specific van is its published tare, and it is on the detail page for every range on the site.
Caravans under 2,500kg ATM/Lightweight caravans/Caravans by ball weight
How to read construction off a spec sheet
Five things to look for, and one of them is a thing that should be there and often is not.
- 1
Look for two words, not one
A spec sheet that says composite is telling you about the cladding, the structure, or both, and you cannot tell which. Look for whether a frame is described anywhere on the same sheet. If a frame material is listed, the composite is cladding on that frame. If the sheet talks about bonded walls, one-piece construction, or no frame at all, it is describing a structural panel.
- 2
Frame material and frame method are separate lines
Meranti, alloy or steel tells you the material. Screwed, riveted or fully welded tells you how it is held together. Both matter, for different reasons, and a sheet that lists one and not the other has left something out.
- 3
Insulation is rated for the material, not the wall
A rating quoted for the insulation is measured on the insulation. The wall it sits in has frame members running through it that the rating does not account for, so treat it as a comparison between vans built the same way rather than a promise about the van.
- 4
Tare is the only weight claim that means anything
No construction method has a published weight you can put in a calculator. Tare is a real measured figure and it settles the question for the one van in front of you. It is on every detail page on this site and on the compliance plate.
- 5
Watch for a name that is not a material
Manufacturers give their wall builds product names. A name is not a specification. Ask what is in it, in materials, and if the answer is the name again, treat the sheet as silent on construction.
We show the wall build on a range's detail page wherever the manufacturer states it.
The walk-up checklist: what to check on the van in front of you
Eight checks, in the order you would do them standing at the van. They work on a new van in a yard and on a ten-year-old one in somebody's driveway, and none of them need a tool.
- 1
Put your eye along the wall from the front corner
Sight down the side of the van from one corner, the way you would check a plank for straightness. Ripples, waves or a bulge that was not there on the van beside it point at a wall that has moved, and on a composite panel a bulge can mean delamination.
- 2
Press the wall low down, near the floor join
Firm pressure with the flat of your hand at the bottom of the wall, near the floor, in each corner and under each window. It should feel solid everywhere. A soft or spongy spot is water damage in a framed wall and delamination in a panel, and both are found this way long before they are visible.
- 3
Read every sealant line, do not glance at it
Follow the sealant around every window, hatch, light, awning rail and the join at each corner. You are looking for shrinkage, cracking, gaps, or a bead that has pulled away from one side. This is where water gets into every build on this page, regardless of what the walls are made of.
- 4
Look at the inside of the same spots
Go in and look at the ceiling and wall lining directly under every roof hatch, air conditioner and window. Staining, a lifted edge on the lining, a musty smell in a closed van, or screws that have rusted from behind all say water has been there.
- 5
Open a locker and look at the raw edge
External lockers and the wardrobe base often show you the wall in cross-section where it is cut. That is the quickest honest look you will get at whether there is timber, alloy, or a foam core in there.
- 6
Ask what the walls are, then ask what the frame is
These are two different questions and the answers are often different materials. Composite cladding over a timber frame is a timber-framed van. Ask both, and ask for it in writing on the order form if the answer matters to you.
- 7
Ask where it gets repaired
Ask the dealer who repairs a damaged wall on that van, and where. A common build has an answer in every town. A structural panel may have one in your state. Neither answer is wrong, but you want it before you buy rather than after a stone or a shopping centre pylon finds you.
- 8
Check the compliance plate against the brochure
The plate on the van is the legal figure. If the tare on the plate and the tare in the brochure disagree, the plate is the one that counts, and a van already carrying dealer-fitted extras can be heavier than any published figure.
None of this replaces an inspection
These checks find the obvious problems before you get emotionally attached to a van. They do not find everything, and on a used van a moisture meter in the hands of someone who does this for a living finds what a hand cannot. Our pre-delivery and used-buying checklists cover the rest of the van the same way.
Matching the build to how you will use it
There is no best build, only a build that suits the trip. Four common cases, and the property that actually decides each one.
- Sealed roads and caravan parks. Nothing here will be the thing that lets you down, so weight and price do the deciding. Check tare against your car and buy the layout you like.
- Long stretches of corrugated dirt. The deciding property is how the structure is joined, not what it is clad with. Welded frames and bonded panels both remove fasteners that corrugations work loose. Ask how the walls attach to the floor and the roof, which is where movement shows first.
- Heat, cold, and staying put for weeks. Continuous insulation with nothing bridging it is what makes the difference, which favours a structural panel. In a framed van, ask what fills the cavity and how the frame members run.
- Remote travel where a repair has to happen locally. Here the ranking inverts. The most common builds are the ones a workshop in a country town can fix this week, and that is worth real money a long way from a capital city.
Whatever you land on, the weight has to work with your car before anything else does.
Common questions about caravan construction
What is the difference between stucco and alucomp caravan walls?
Stucco is a single thin aluminium sheet with a dimpled finish rolled into it, fixed over a frame. Alucomp is an aluminium composite panel, two thin aluminium skins bonded either side of a plastic core, fixed over a frame in much the same way. The practical differences are appearance and stiffness rather than structure: the composite sheet stays dead flat where the dimpled sheet is textured to disguise the ripples a flat thin sheet would show, and alucomp comes in larger sheets so a wall has fewer joins to seal. Both are cladding. In both cases the frame behind the cladding is what carries the load, and the insulation is whatever fills the cavity between the frame members, so neither choice on its own tells you how well the van is built or how heavy it will be.
Which is lighter, a composite caravan or an aluminium one?
It depends which two things are being compared, and the honest answer is that the material tells you less than people expect. A full composite sandwich body, where a foam-cored structural panel replaces the frame, the batts, the cladding and the inner lining all at once, is generally the lightest way to build a wall for a given stiffness. But a caravan is far more than its walls: the chassis, suspension, water tanks, batteries and fitout usually outweigh the body, so a large composite van can easily be heavier than a small aluminium-clad one. Comparing an aluminium FRAME against a timber frame is a different question again, and there the aluminium frame is lighter. The number that settles it for a specific van is the published tare weight, which is a measured figure rather than a claim about a material.
Do composite caravans still get water damage?
Water still gets in, at exactly the same places it gets into any other van: windows, hatches, awning rails, service points and corner joins, all of which are penetrations held out by sealant. What changes is what happens next. A composite panel has no timber to rot and a foam core that does not absorb water, so a leak is usually a repair rather than a structural problem. The failure specific to composite is delamination, where water or heat breaks the bond between the skin and the core and the panel loses its stiffness. It shows up as a soft spot or a visible bubble, which is why pressing the wall low down is on the walk-up checklist.
Is a timber-framed caravan a bad buy?
No, and treating it as one misreads the trade-off. Timber framing is the most repairable build in the country, the cheapest to have repaired, and the one every caravan workshop knows how to work on. Its weakness is specific rather than general: timber that stays wet will rot, and rot in a wall frame is structural and often advanced before it is visible. That makes it a maintenance question, not a quality question. If you check and renew sealant on schedule and deal with leaks quickly, a timber frame does its job. If a van has been left to leak for years, the build that will punish you hardest for it is this one.
Does a fully welded frame matter for corrugated roads?
It is one of the reasons welded frames exist. A screwed or riveted joint relies on a fastener holding clamp, and thousands of kilometres of washboard road works fasteners loose. A welded joint has nothing to loosen. That does not make a screwed frame unsuitable for dirt, since plenty of vans cross the country on them, and it does not make a welded frame indestructible. It removes one specific failure mode that corrugations cause, which is worth paying for if corrugations are what you plan to do.
How do I tell what a caravan is built from if the spec sheet does not say?
Ask two separate questions, because they have separate answers: what the walls are clad with, and what the frame is made of. Composite cladding over a timber frame is a timber-framed van, and a sheet that lists only the cladding has told you half the story. If the answer to either question is a product name rather than a material, ask what is in it. On the van itself, external locker openings and the wardrobe base often expose the wall in cross-section where it has been cut, which is the fastest honest look at whether there is timber, alloy or foam in there.
Does construction type affect what my car can tow?
Only through the tare weight, and only for the van in front of you. Your car's braked towing capacity has to cover the ATM of the van, and your car's payload has to cover the ball weight plus everyone and everything in the car. Neither figure cares what the walls are made of. Two vans built completely differently can share an ATM, and two vans built identically can be hundreds of kilograms apart on size alone. Run the actual published figures through a tow check rather than reasoning from the build.
Everything on this page is general information about how caravans are built. We do not rate or rank manufacturers on construction, and we do not publish a build for a specific van unless the manufacturer publishes it themselves.