Sprache wechseln
If the idea of owning a rooftop tent is still new to you, and you’re in the throes of learning as much as you can before shelling out some of your hard-earned savings, then don’t let the typical pictures on your favourite social media channel woo you into believing camping on top of your vehicle is just warm summer nights under starlit skies. I know, you’ll be expecting torrential downpours, howling winds, and maybe even ice and snow. But with all the excitement going on around you, you mustn’t forget some important housekeeping.
In the realm of rooftop tents, ventilation is not just a luxury; it is a vital necessity, whatever the season. At its core, ventilation serves as the essential mechanism for maintaining air quality inside the tent. So let’s begin with the “why” before we get to the “how.”
SEASONS
Think of the height of summer: sweltering days and hot nights. Crawling into an oven-like rooftop tent will make you want to unzip every opening to let even the slightest breeze waft through. Lying on the mattress, you’re probably going to sweat.
Spring and autumn: Well, the weather can go through every stage from cold and dry to warm and damp, cold and damp to warm and dry. One night you’re warm, the next you’re burying yourself under the covers.
Winter: You know it’s crispy cold outside, so you’re tempted to ramp up the heat any way you can and close everything to prevent hot air escaping or the cold creeping in.
It doesn’t matter what time of the year it is, or how high or low the temperatures are: some rules apply. Always. The first rule is that we are warm-blooded creatures who exhale and transpire bodily fluids through every pore of our skin. We can’t control it, but we do contribute to a warm and humid atmosphere. And therein lies the problem: the moisture we create gets into the mattress, the bedding, settles on the tent materials… and it lingers.
One day you may feel the damp bed, smell a strange odour, or worse, see traces of mould appearing on different surfaces. To be honest, if your senses are alerted by any one of those alarm bells, go looking for the others. And look everywhere.
The warmer months are easier to cope with because we’re quick to leave the tent open. But those cold and clammy months present a host of problems:
– We don’t want to let the damp in, so we close everything up.
– We forget that we’re bringing potentially damp clothes and shoes in with us, which, heaven forbid, might be left inside because the next morning is more cheery and bright, and that waterproof jacket isn’t needed right away.
– This is not necessarily so obvious: tent materials differ. Soft-shell tents have some sort of fabric and a metal skeleton to hold it up. Hard shells and hybrids have large solid surfaces, soft tent fabric, and metal structures to support the roof and keep everything stable.
Different materials respond differently to different temperatures, and condensation forms everywhere. In corners, on nuts and bolts, on gas struts, on the floor under the mattress.
Take my word for it, condensation is everywhere. It’s sneaky, because you can’t always see it, and it’s a bigger problem than the heaviest of downpour—you can see where the rain is coming in through all the obvious openings like the door, windows, and the damp clothes you brought in with you. Condensation, on the other hand, settles where warm air meets a colder surface.
Think I’m rambling? Trust me, condensation and ventilation should be at the top of your list of concerns, in big bold letters.
PREPARE
Take a good look at the tent that’s caught your fancy and be inquisitive.
Soft surfaces
Don’t be misled by high-tech, super-thin, silicone-coated, waterproof fabrics which may be as light as a feather—they don’t breathe. Condensation will be running down the inside walls when you wake up in the morning. Heavier synthetic materials that shine with high levels of water resistance will suffer the same plight. Canvas, on the other hand, is heavy, but this cotton shield breathes well.
Ask the manufacturer or salesperson about material breathability, waterproofing and, in the case of canvas, whether the protective coating has been applied to the interior or exterior surface. Refer also to 7/31 Weatherproofing.
Your tent material needs to breathe.
Hard surfaces
You know what it’s like when you get in the car in the middle of winter and the heating isn’t yet up to speed. You breathe out and the windows mist up. Condensation. The same applies to hard surfaces in a rooftop tent. Is the roof insulated? Are there any rivets or other fastenings that can act as a thermal bridge—this will be where moisture collects before seeping into the soft material they hold together.
Do the hard materials have soft, curved corners or are they sharp? The rounder a corner, the better the airflow.
Look for soft shapes, good insulation, and make note of any fixings that can act as thermal bridges. Ask if the materials have been treated with mould protection.
Mattress
We looked at this in 10/31 rooftop tent mattresses. A ventilation mesh/anti-condensation mat isn’t an option, it’s an essential. Under the mattress is where things can get really ugly. Think of perspiration seeping down towards a cold floor, settling in a protected space without any airflow, and then being warmed up every night for bacteria to have a reproductive party.
A ventilation mesh/anti-condensation mat is a must.
Windows, doors, skylights
The more the merrier. And not just those to look out of, but to open and let fresh air in and stale air out.
But don’t forget about the creepy crawlies and critters that bite in the night. All doors and windows must have protective mesh small enough to keep those beasties on the outside.
A small porch above windows and doors means they can be opened in all weathers without the risk of rain or snow getting in.
HOW AND WHEN TO VENTILATE
Obviously, unzip every opening and let the air in first thing in the morning. That’s a good start. But take out the bedding whenever you can and let it air out properly, while the mattress gets a chance to breathe, too.
Airing the tent in the morning isn’t something done in ten minutes. You possibly spent six, seven, maybe eight hours breathing and perspiring in there, so you need to let the soft surfaces dry as best they can, for as long as they can. If you have to set off early, then open up the tent again as soon as you arrive at your destination.
On a hot summer’s night, you won’t think twice about leaving the windows unzipped. But the same is true at any time of year. Even when it is really cold outside, ventilate and don’t fall into the trap of ramping up the heat or dressing up so warmly that you break into a sweat and make matters worse.
Rain and persistent fog give soft materials the opportunity to absorb moisture, and chances are that you will have to pack away a damp tent when you leave the campsite. It goes without saying that you need to open the tent and let it dry thoroughly as soon as possible. This may well be impossible if you find yourself in a 14-day downpour on some windy isle. Just do it whenever you get the chance.
Another thing to keep in mind is cleanliness. You will avoid bringing sand or dirt into the tent, but accept that some will get in and gather in the corners around the floor anyway. This material absorbs moisture as well and dries more slowly, which, if left unattended, will escalate the risk of odours and mould.
At the end of every trip, and if you want to put your tent into storage, ventilate, dry and clean your tent diligently. If you can, open it from time to time and give both tent and mattress an airing.
CONCLUSION
Ventilation is more than just opening windows. It is vital to your health and the health of your rooftop tent. You will spend some serious money on your lofty abode, so take every precaution to look after it.
Before purchase, check the materials and how the tent is constructed. Check how many widows, doors and vents actually open. Is the mattress supported on a ventilation mesh/anti-condensation mat?
After purchase, ventilate as often as you can, thoroughly dry the tent after a downpour, and air the bedding properly. In winter, ventilate at night and wrap yourself up as necessary.
