Tent waterproofing doesn't last?

[furious]

Hi fellows!

I am a bit disappointed about the waterproofing ability of the tents. I have a Marmot Swallow. It is a very practical tent! I love its versatility, space, ventilation and high quality in general. It was absolutely waterproof, even when the rain was so heavy that a flood of a few centimeters was formed on the ground.

I bought it 6 years ago and I have used it for 230 nights approximately in any kind of weather: a lot of sun, downpours, strong winds and a little bit of snow. The last time I used it, I noticed that it's not waterproof any more. Water was leaking through the fly and it was getting in the inner tent through the roof. It seemed it was not leaking through any seams, but straight through the fabric! I could see the drops of water.

I visited the outdoor shop from which I had bought my tent and I was very disappointed when the shopkeeper told me that this is absolutely normal, because the UV radiation polymerizes the tent's plastic. He said that mountaineers use these tents only in one expedition on the high mountains! High-altitude speeds up the polymerism of the plastic. Maybe half of the times I 've used my tent, it was on high-altitude, I should say.

When I bought such an expensive tent (430 euros), I expected it to last many years. Unfortunately, according to that shopkeeper, I should buy another tent and waterproofing sprays won't make any difference on my tent. I have never treated my tent with a waterproof spray. Maybe the worst is that the shopkeeper told me there isn't any kind of fabric which will be waterproof after many years of camping. According to him, we should buy a new tent every once in a while, but I hope that's not true!

Do you have any experience with that? Is there a tent that you have used a few hundreds of nights and it's still absolutely waterproof on heavy rains?

[Warin]

Very expensive tents are Silnylon

yours is probably ripstop nylon with a PU coating
Silnylon is the same with a silicon coating ...

As you say they 'go off' with UV exposure. So keeping them away from sun over long periods is a good idea. The fly will cop most of it - so either a cover over the fly (a fly on a fly ? ) or expect to replace it.

http://www.backpackinglight.com/cgi-...hread_id=67310 has a discussion on treatments - inconclusive.

[Genghis9021]

UV destroys man-made materials very quickly.

And it's not just tents. All that nylon and polyester being used by motorcyclists for their jackets and pants . . . should be retired, too. The tear resistance declines precipitously with sun exposure.

Your tent served you well - less than 2 Euro / night.

Sure, you could find a canvas tent that would resist the sun better. It would weigh 5x as much, if not more, have spotty water resistance unless it was specifically shaped (and then would offer much less usable space).

In the end, it's always tradeoffs.

[markharf]

Yup, there are more UV-resistant tents and less UV-resistant tents. Pitching at high altitudes or in arctic summers, particularly in direct sunlight, will trash fabrics and waterproofing alike at accelerated rates. What the salesman told you is true: in cases of extreme UV exposure, most tents last only a month or so. If you shop wisely, increased UV resistance is one of the little-known features which make truly expensive tents (Hilleberg being my favorite) a better deal than cheap ones.

It probably won't console you much, but in my experience when they start to leak like that the fabric is already sufficiently weakened that you don't really want to trust it to protect you against wind or snow-loading anyway. You'd be astonished how easily it'll tear.

Depending on the degree to which the fly covers the tent inner, you can sometimes get away with replacing the fly alone, since it tends to take the brunt of the exposure. On the other hand, if you've had it pitched out in high-altitude sun a lot you might find that the floor seams (which are often exposed just below the lower edges of the fly) have weakened so much that you really need a whole new tent.

Hope that's helpful. Of course, this is about the time that someone comes on here to describe the several decades of flawless service they've had from their 20 quid special, which has withstood hurricane winds, year-round arctic UV, incalculable snow-loading, and who knows what else. Take my advice and theirs with whatever grains of salt you deem appropriate.

Mark

[furious]

Thanks, guys, for the useful replies!

Unfortunately, it seems there is no tent to last forever, indeed.

Mark, that's exactly what I was wondering about. I 've read so many comments about people using their fabulous tent for decades which still serves them as if it was new. That's why I wrote about the amount of nights somebody used his tent. Of course, if I would use it for 20 nights per year, it would last more than 10 years.

[McCrankpin]

I'll add a bit here.
Many years ago I bought a high-spec bicycle-weight tent, all modern synthetic material.
I camped in it for 101 consecutive nights.
But I wonder, is the number of full days that the tent was erected more relevant?
Riding from place to place, staying one night only each time, your tent won't see much sunlight.

I'd estimate that on my 101-day ride, my tent saw about 30 to 40 complete sunny days (it was sunny the whole journey - wonderful! And I never bothered to search out shade as temperatures weren't high most of the time).
And when I came to use it again some time after that trip the fly had deteriorated a lot. Sort of, very thin patches of surface material peeling away. The manufacturers said that was to be expected.

So now, I carry a thin opaque tarp to put over the fly if I'm doing a lot of sunny camping.
All the very-lightweight tents I see these days carry a warning about sunlight exposure.

[Genghis9021]

McCrankpin (fantastic handle) I think you're on to something.

Somewhat akin to an airframe (hours rated) or a even a race engine (hours rated) that's the key metric - hours of UV exposure with a factor for altitude (if that's relevant). Latitude should also be a factor (it is in many engineering texts).

People in California generally consider the sun strong there. After living for 6 years in India . . . the California sun seems quite tame. T-shirts faded super quick, bicycle tires were destroyed if left in the sun, etc. The difference - 40 degree's latitude vs 12 means ALOT more direct (high sun) light per day.

LOTS of people are now using a tarp to shade their tent for the reasons you've stated.

[Warin]

Lets not get into a 'mine is more' argument ... some data

This map shows world levels in 2009.

UV Index Worldmap | UNEP/GRID-Arendal - Maps & Graphics library

You can see the relative levels. Light blue = most UV. You can see the southern hemisphere gets more when compared to the northern hemisphere (explains why photo exposure levels are very different from one hemisphere to the other).

From Sun Protective Clothing | UPF Clothing | UV Protection | Arthritis Today Magazine

Nylon (as used in tents/flys/tarps) absorbs UV fairly well, darker colours look to do it better than lighter colours. So maybe a tarp over the tent will extend the tent life. Of course this only applies in day light hours. So the number of nights may not be a true indicator, possibly he number of days the tent is up during the day?

[brclarke]

You got 6 years of usage out of it... That seems pretty good to me.

Me being thrifty (cheap) I always buy a cheap tent, spray the snot out of it with waterproofing spray, and just assume that it'll only last a year or so. If it lasts any longer without leaking, that's just a bonus!

[furious]

Now comes another question: Does any tarp and any kind of fabric over the tent protect the tent from UV?

[Warin]

It follows from

As the tent material it self absorbs UV then tent material would protect another tent under it ...

A few feet of lead would be better ... but I don't think you'd want to carry that around with you. Similarly other materials will be heavier than ripstop nylon with PU coating ... or silicon coating if you want to go to that expense.

Note UV is only 2% of the suns radiation, the other bits are evenly divided between visiable and infared.

[Bigfoot 2]

Hang on a minute, if it's UV-light/radiation that is causing the early demise of the fabric, is there not a UV-barrier-coating that can be applied before (and maybe during) each trip?

I'm not suggesting you smear it with a dozen tubes of factor-100 Ambre Solaire or try to cover it with 3000 pairs of RayBans, but something MUST be available on the market to defeat or minimise the damage.

I'm surprised the manufacturers aren't adding a coating for UV-resilience. Actually, no I'm not - that would surely be akin to the fabled 'everlasting lightbulb' or the premise behind that classic 'Man in the White Suit' film.

In answer to the question about what is required as a screen, I don't speak from experience but the answer would be 'just about anything as long as it shades the tent'... Provided, that is, that you're not camping next to something significanltly light-reflective, like snow or a b ody of water - in which case you might consider shielding the tent-walls from that as well.

[g6snl]

What if the tent was covered in one of them foil survival blankets ? Maybe everything should be covered in foil, may last for ever then ! Might get a few funny looks going down the road on a foiled covered bike with foil covered kit.

Must have be tried surely....................

[furious]

Originally Posted by Bigfoot 2

Hang on a minute, if it's UV-light/radiation that is causing the early demise of the fabric, is there not a UV-barrier-coating that can be applied before (and maybe during) each trip?

I'm not suggesting you smear it with a dozen tubes of factor-100 Ambre Solaire or try to cover it with 3000 pairs of RayBans, but something MUST be available on the market to defeat or minimise the damage.

I'm surprised the manufacturers aren't adding a coating for UV-resilience. Actually, no I'm not - that would surely be akin to the fabled 'everlasting lightbulb' or the premise behind that classic 'Man in the White Suit' film.

In answer to the question about what is required as a screen, I don't speak from experience but the answer would be 'just about anything as long as it shades the tent'... Provided, that is, that you're not camping next to something significanltly light-reflective, like snow or a b ody of water - in which case you might consider shielding the tent-walls from that as well.

Sure, there is UV-protective coating. Most tents come with it and you can renew the coating with products like Nikwax. The thing is that for people who travel for many months in a row and camp often, it's a problem to carry cans of Nikwax. I 'm wondering how often I would need to renew that coating. If renewing it every few months is enough, I think I will end up doing this.

[furious]

Originally Posted by g6snl

What if the tent was covered in one of them foil survival blankets ? Maybe everything should be covered in foil, may last for ever then ! Might get a few funny looks going down the road on a foiled covered bike with foil covered kit.

Must have be tried surely....................

I found something which seems interesting:
Emergency Camping Shelter, Ideal For Runners, Hikers etc. 2.5 m x 1.5 m: Amazon.co.uk: Garden & Outdoors

but this material is so thin, I am afraid it may be ruined easily by the wind.