Points of interest

Points of Interest

Why wall structure is so important for longevity and comfort.

3rd May 2011

There are four main constrcution methods for 5th wheel and caravan walls.  The cheapest and most problematic is aluminium cladding. 

Aluminium Cladding - The trailer will start off with a timber frame, often stapled and glued together.  The Aluminium is then stapled to the frame starting at the bottom and working up.  The biggest issues with aluminium cladding is repairs are often expensive and its very hard to get it looking the same as before.  Leaks happen a lot as the aluminium sheets can bend in the wind or when someone leans against the tralier wall.  This tends to break the sealant away.  They also tend to have thin fibreglass batts for insulation which can quickly degrade and offer very little insulation.

Pinch rolled fibreglass - A cheaper and mass production way of producing a fibreglass clad wall is by pinch rolling them.  A thin fibreglass is glued to a luan board backing (wood/cardboard) then run through pinch rollers with the wall frame and polystyrene filling.  A very fast setting glue is used for the lamination.  The fast setting glue results in only top-surface bonding and the layer of luan board is very susceptible to moisture and often causes delamination.

Fibreglass to wall board - Some units are glued together as they have no wall framing to allow mechanical fixings.  It saves on insulation (have none) and the cost of rivets etc.  The disadvantages are very cold in winter and very hot in summer as well as not being able to have slideouts etc.

Vacuum Bonded - Vacuum bonding is the best way for constructing walls, but due to the time & labour costs it is not done by mass producers.  In our case we use a thick fibreglass with a smooth gelcoat finish.  This allows us to have no luan board between it and the frame/insulation.  The fibreglass is layed flat on the vacuum table and glued, then the frame/insulation is placed on top.  Ontop of this the glued internal wallboards are layed down then the table top is lowered.  The wall is then put under 40-50 ton of even pressure for 6-8 hours while the glue cures.  As the glue has a longer setting time it has much longer to permeate the foam and etch to the frame and fibreglass.  You end up with a very strong laminated panel.  We also take it a step further and use a polyurethane foam with over twice the insulation value of polystyrene and better durability. 

The term "Carrying Weight" is different to "Cargo Capacity"

19th March 2011

Carrying weight is an American term that is often used by USA manufacturers.  It has been adopted here by some importers of USA built 5th wheelers.  Carrying weight is the amount of weight that a 5th wheeler can legally carry (up to the ATM) but it also has to include such items as A/C, spare wheel, batteries, awning, full gas bottles and in some instances the free standing furniture in the 5th wheeler. These items often add an aditional 200kg+ to the weight of the 5th wheeler. 

The term used by Australian & NZ manufacturers is cargo capacity.  This term refers the weight that can legally be carried (up to the ATM) with the above items already accounted for. So the cargo capacity is how much water, food, clothes, toys etc you can take in the 5th wheeler.