The short answer: payload is the difference between what your caravan weighs empty and the maximum it is legally allowed to weigh loaded, and it disappears faster than most people expect. A sprung mattress is one of the single heaviest items in a caravan, and it sits high up and usually behind the axle, which is the worst combination for towing stability. Swapping it for high-density foam typically frees up around 15 to 25kg and lowers the centre of gravity slightly at the same time.
Where your payload actually goes
People budget for the obvious things and get caught by the rest. Water is the classic: a full fresh water tank is a kilogram per litre, so 90 litres is 90kg, which on many caravans is a large share of the entire payload allowance before anything else is loaded.
Then come gas bottles, a battery, an awning, recovery gear, tools, food, bedding, clothes, camp chairs and a braai. None of it feels heavy individually. Collectively it is the whole allowance.
The mattress rarely gets weighed at all, because it came with the caravan and feels like part of the furniture rather than payload. Depending on the caravan and how it is registered, it may be counted in the unladen weight, but the moment you replace it with something heavier, the difference is coming straight out of what you can carry.
Why height and position matter, not just mass
Two caravans carrying the same total weight can tow completely differently depending on where that weight sits.
Height. Weight carried high raises the centre of gravity, which increases body roll in crosswinds and when a truck passes you. A mattress sits at roughly waist height, well above the floor, so it counts as high-mounted weight.
Fore and aft position. Weight positioned well behind the axle acts on a lever and reduces the download on the towball, and light towball weight is strongly associated with caravan sway. In most layouts the fixed bed is at one end of the van, frequently the rear, so the mattress is precisely the kind of weight that affects balance most.
This is why replacing a heavy sprung mattress with foam is worth slightly more than the raw kilogram figure suggests. You are removing weight from a bad location.
| Item | Typical weight | Where it sits |
|---|---|---|
| Full 90 litre fresh water tank | About 90kg | Usually low and near the axle, which is the good case |
| Two 9kg gas bottles, filled | About 40kg | Nose, adds towball weight |
| Leisure battery | About 15 to 30kg | Usually low |
| Sprung caravan mattress | Meaningfully heavier than foam, commonly by 15 to 25kg | High up, often behind the axle |
| High-density foam caravan mattress | Light enough to lift one-handed | Same place, far less of it |
What you gain beyond the kilograms
- You will actually lift it. Airing the mattress and getting at the storage underneath is the main thing that prevents condensation mould. A mattress light enough to lift with one hand gets lifted. A heavy one gets left flat until there are black spots underneath it.
- It goes in through the door. A foam mattress is vacuum-rolled into a box that carries through a standard 65cm caravan door and expands on the bed. A rigid sprung mattress has to physically fit through the doorway as it is, which on a queen is a genuine wrestling match.
- It can be cut to the bed shape. Island beds taper, French beds have a cut corner, some layouts have a wheel-arch notch. Foam cuts cleanly to any of those. A coil unit does not.
- Nothing to corrode. No steel in a damp, sometimes salt-air environment.
Not at the cost of support
Saving weight is easy if you do not care about sleeping. The trap is that the lightest foam is also the lowest density, and low-density foam bottoms out under an adult and gives you the sore back that started this whole search.
The number to hold onto is density in kg/m3, and it is not the same thing as firmness. Both our caravan mattresses use 50 kg/m3 SABS-approved high-density foam, above the 30 to 40 kg/m3 benchmark most caravan buying guides recommend, and the same grade we use in our home range.
The Revive Foam Caravan Mattress is the one we suggest first: an open-cell memory foam comfort layer over that high-density core, which is what solves the pressure and sore-back complaints. The Active Foam Caravan Mattress is the firmer, more traditional build on the same core.
Frequently asked questions
How much does a caravan mattress weigh?
It varies by size and construction, but the useful comparison is between types rather than absolute figures: a sprung caravan mattress is commonly 15 to 25kg heavier than a foam one of the same size, because of the steel coil unit. Foam versions are generally light enough to lift and turn single-handed.
Does the mattress count towards caravan payload?
Depending on the caravan and how it was weighed and registered, the original mattress may be included in the unladen figure. What is certain is that if you replace it with something heavier, that extra weight comes directly out of your usable payload. The only reliable way to know your real numbers is a loaded weighbridge check.
Does a lighter mattress improve caravan towing stability?
It helps, because a mattress sits high up and usually well behind the axle. Weight carried high raises the centre of gravity and increases roll, and weight far behind the axle reduces towball download, which is associated with sway. Removing 15 to 25kg from that position is worth more than the same saving low down and near the axle.
Is lighter foam always better for a caravan?
No, and this is the important caveat. The lightest foam is the lowest density, and low-density foam bottoms out under an adult within a couple of seasons. You want the weight saving that comes from choosing foam over springs, not the weight saving that comes from choosing bad foam over good foam.
Tight on payload? Foam over springs is one of the easiest 15 to 25kg you will ever save, and it comes off a high, rearward position. 50 kg/m3 SABS-approved foam, cut to your bed shape, 365-night trial, 10-year written warranty.
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