A good roof top tent mattress is 50 to 100mm of dense foam that fits your tent's floor exactly and still lets the lid close. Memory foam or high-density foam both work, and many comfort or condensation problems can be fixed with a thin topper or an anti condensation mat, not a new mattress.
Many roof top tents come with a foam mattress. The question is usually whether it's good enough, how to make it better, and why it's damp underneath some mornings. This guide covers thickness, foam types, toppers, condensation and when to replace it.
How Thick Should a Roof Top Tent Mattress Be?
For most people, 50 to 100mm of good foam is enough, because the tent floor is flat and firm. You don't need the 200mm or more of a house mattress. Quality matters more than thickness: dense foam at 70mm can feel better than cheap foam at 100mm.
The real limit is your tent. In a hardshell, the mattress stays inside when it closes, so it has to share the space under the lid with the folded canvas and your bedding. A thicker mattress means less room for a doona, or a lid that won't latch. Softshell tents fold in half, so the mattress folds too, and a very thick one can stop the cover zipping up. Our guide to hardshell vs softshell roof top tents explains how each one packs.
| Thickness | How it feels | Watch out for |
|---|---|---|
| Under 50mm | Firm. Side sleepers may feel their hips on the base | Cold comes through faster |
| 50 to 80mm | Comfortable for most back and side sleepers | Foam quality matters a lot here |
| 80 to 100mm | Plush, closer to a house bed | Check the tent still closes with bedding in |
| Over 100mm | Soft, heavy, bulky | Often won't fit a hardshell or fold in a softshell |
The RIGDUP Nomad 1.4M comes with a 70mm memory foam mattress. It's a clamshell hardshell that sits 18 cm tall closed, so every centimetre under the lid counts.
What Type of Foam Is Best for a Roof Top Tent Mattress?
Memory foam and high-density foam are the two common choices, and both work well. The better pick depends on how you sleep and where you camp.
| Type | Good for | Downsides |
|---|---|---|
| Memory foam | Side sleepers, pressure points, a soft settled feel | Firms up in the cold until your body warms it. Holds heat on hot nights |
| High-density foam | Even support, holds its shape, springs back quickly | Feels firmer than memory foam |
| Memory foam on a dense base | Comfort on top, support below | Usually thicker and heavier |
| Latex | Springy, breathes better than memory foam | Heavy, and hard to find cut to tent sizes |
| Air or self-inflating mattress | Packs flat, adjustable firmness | Can puncture, and air gets cold on cold nights |
Memory foam softens with heat. On a cold night in the High Country it can feel firm at first, then settle as it warms. On a humid night up north it can feel warm, so a breathable cover helps.
Whatever foam you pick, look for a removable, washable cover. You sweat into it every night, and a cover you can wash is far easier than a mattress you have to scrub.
Does a Roof Top Tent Mattress Keep You Warm?
Yes, the mattress is your main insulation from the cold under the tent. A roof top tent sits in moving air, and cold comes up through the base all night. On cold trips, how well the mattress insulates matters as much as your sleeping bag.
Camping mats use R-value to show this. Cascade Designs, the maker of Therm-a-Rest, explains that a higher R-value means more resistance to heat loss, and that the ASTM F3340 test lets you compare mats across brands. Many roof top tent mattresses don't list an R-value, so judge by thickness and foam: thicker solid foam usually insulates better than thin foam or air.
On a cold trip you can add warmth under you without changing the mattress:
- A wool blanket or a closed-cell foam mat under the fitted sheet
- A thin foam topper, if the lid still closes
- A sleeping bag rated for the night, with a blanket underneath you
Should You Add a Mattress Topper to a Roof Top Tent?
A topper is the cheapest way to make a stock mattress softer, as long as the tent still closes with it in. For a hardshell, a 25 to 50mm topper is a sensible place to start. Test it at home with your full bedding before a trip.
- Memory foam toppers add softness for side sleepers and ease pressure on hips and shoulders
- Egg crate foam is light and lets some air move, but compresses quickly
- Wool toppers breathe well and help on humid nights, but don't add much cushioning
- Self-inflating mats can go on top for cold trips, then roll up and live in the car
If the topper won't fit with the tent closed, carry it rolled in the car and throw it in at camp. It's an extra job at each stop, but it keeps the lid sealed. Never force a lid shut over a thick topper: it strains the struts, latches and canvas.
Why Is It Wet Under My Roof Top Tent Mattress?
It's condensation. You give off warm, moist air and sweat all night, and it moves down through the foam. When it reaches the tent base, which is cooled by the night air underneath, it turns back into water.
The Australian Government's YourHome guide explains this as the dew point: moist air meeting a surface cooler than itself. A metal base on a cold night is that surface. The RIGDUP Nomad 1.4M has an aluminium honeycomb base, and like any solid base it can get damp under the foam if no air moves there.
The moisture can't dry out because the mattress sits flat on the floor. Leave it for a few trips and mould can start underneath, where you can't see it. The Victorian Better Health Channel advises not to put mattresses on the floor or on poorly ventilated surfaces as one way to prevent mould.
How Do You Stop Condensation Under a Roof Top Tent Mattress?
Lift the mattress off the base with an anti condensation mat, and air it often. The mat is a springy 3D mesh layer that holds the foam up so air can move underneath.
- Fit an anti condensation mat under the mattress, cut to the floor size
- Open the vents at night, even on cool nights, so moist air gets out
- Lift the mattress each morning and let the underside air while you have breakfast
- Stand it up in the sun after each trip
- Keep wet gear out of the tent
Check that your tent still closes with the mat in, because it adds height under the mattress. Some tents include one: the Rigdup 1.3M has a condensation pad in the box. If yours doesn't, check the in-the-box list before buying, then measure. Our full guide covers how to stop condensation and mould in a roof top tent, including airflow and storage.
What Size Mattress Fits a Roof Top Tent?
One cut to your tent's floor, which is rarely a standard bed size. Measure the stock mattress, not just the inside of the tent, because many have cut corners or a taper for the hinge or ladder side.
The Nomad 1.4M is 210 x 145 cm inside. That's longer than a standard Australian queen bed and narrower, so a house mattress won't fit. If you have foam cut to replace yours:
- Trace the old mattress on paper, including any cut corners
- Keep the same thickness, or check the lid still closes with a thicker one
- Ask for a removable cover with a zip, so you can wash it
- Pick a cover fabric that breathes, not a plastic one
Should You Replace or Upgrade Your Roof Top Tent Mattress?
Replace it when it's worn out or mouldy. Upgrade it with a topper when it's fine but too firm for you. Many owners only need a topper or a mat.
| Problem | What to do |
|---|---|
| Too firm, sore hips or shoulders | Add a 25 to 50mm memory foam topper |
| Damp underneath | Add an anti condensation mat and air it more |
| Cold through the base | Add a blanket or foam mat under the sheet, or a warmer sleeping bag |
| Dips that don't spring back | Replace the foam |
| Mould inside the foam or a smell that won't go | Replace the foam |
| Cover torn or worn | Replace the cover only |
Foam that has gone mouldy inside is hard to clean properly. Surface marks on the cover can often be washed out, but if the foam itself smells musty after airing, replace it. If you're weighing up a new tent instead, start with our guide on how to choose a roof top tent.
FAQs
Can you use a normal mattress in a roof top tent?
Not usually. House mattresses are too thick and the wrong shape for a tent floor. Foam cut to your tent's size works better and lets the tent close.
Is 70mm memory foam thick enough for a roof top tent?
For most people, yes. The tent floor is flat and firm, so 70mm of memory foam gives good support. Side sleepers who want more softness can add a thin topper, if the lid still closes.
How do you clean a roof top tent mattress?
Take the cover off and wash it to its care label. Vacuum the foam, spot clean any marks with mild soapy water, and dry it fully in the sun before it goes back in.
Do you need an anti condensation mat in a hardshell roof top tent?
It helps in any tent where the mattress sits on a solid base. If you camp in cold or humid places, it's one of the cheapest ways to stop damp under the foam.
Which Roof Top Tent Comes With a Memory Foam Mattress?
Many do, so check the thickness and the inside size on the spec sheet. The RIGDUP Nomad 1.4M is a clamshell hardshell that sleeps 2, with a 70mm memory foam mattress and a 210 x 145 cm inside. You can compare it with the rest of our roof top tents, or see the RIGDUP Nomad 1.4M roof top tent.
