Mysterious leak in Thermarest.

[puredingo]

Hello, My Thermarest has a slow leak that, for the life of me, I just can’t find.

I can sleep on it but have to re-inflate two or three times through the night. I’ve tried the soapy water thing and listened intently at the valve to no luck.

Any tips on fixing it or even a repair service in Australia would be good, I can’t find anything?

[Huntsman247]

Have you stuck it in a bathtub?

[puredingo]

Yeah I did mate, I haven’t got a big bath so I wrestled it around but couldn’t see anything?

I would take it down the beach but it’s howling Southerly and about 10 degrees.

[Zapruda]

Check the valve. Sometimes they get dirty and don’t seal properly. It’s happened a few times to me. A bit of compressed air does the job.

[Lamont]

Bathtub can be a problem unless you manage to work the whole thing under water. Pump it up as hard as you can. Do it in thirds-get a big uncreased section under, then move onto the next. If it's the valve you will know straight away if you submerge just that section.
If the mat is creased when you put it under water it may not leak.
Just wondering are you sure it's a leak? Sometimes when it's colder- you need to top up/reinflate before bed. Good luck solving the issue.

[andrewp]

Take a spray bottle and fill it about 1/3 with water, add a few drops of washing-up liquid. Don't shake it. Blow the mattress completely up. Spray half the mattress with the soapy water. Apply pressure to the other half. Folding the mattress over helps apply more pressure. Look for a bubble to rise. Repeat with the other half and then turn the mattress over and repeat. You probably want to do this outside as it's a bit messy. This has always worked for me, even with small holes that take all night to deflate.

[Orion]

It can be a real pain to find those leaks. I just finished locating one after first giving up in frustration and then trying a second time. I usually blow up the pad and then fold it in half, submerge it in warm water, and then hope I spot a tiny stream of bubbles. The soap thing has never panned out for me. When I couldn't find it in the bathtub I considered sending it to Thermarest. But with Covid-19 they aren't accepting mats. So I put it in the bathtub again and did something new: I stood on it. It took a few minutes but I finally saw the bubbles, just a teeny-tiny stream.

I patched it.

It still leaks.

So it's back to the bathtub to look further. These mats suck in this regard. There was one mat that I just gave up on and bought a new one. Another I convinced the local retailer to replace. I don't know about this current one. I guess I'll try some more but I don't have anything close to 100% confidence that I'll stop the slow leak.

I miss the days when I was content to sleep on a single piece of ensolite.

[GregG]

It sounds like this is one of those niggling slow leaks that can't be found, could even be multiple very tiny leaks. I'm wondering how old it is? It might be time to retire it. My Thermarest Ultralight 3/4 is 19 years old and I have been waiting for it to peg out for a while now but somehow it just keeps chugging on. Damn miracle considering some of the terrain it has been on, although I always inflate it on the soft side which tends to help against punctures.

[puredingo]

Well, had another good go at it and couldn’t find a thing? The soap thing was sort of inconclusive, not sure I was doing it right. Put the valve in the sink and a couple of bubble escaped which made me think I’d cracked the case...but the bubbles stopped so that can’t be right.

It’s probably 2 years old...maybe only 10 or 15 sleeps all up because a swap it out with my S2S ultralight mat. Not sure what to do with it, I kind of wish it was a unfixable giant tear and I could be done with it. I deplore waste.

[Zapruda]

Well, had another good go at it and couldn’t find a thing? The soap thing was sort of inconclusive, not sure I was doing it right. Put the valve in the sink and a couple of bubble escaped which made me think I’d cracked the case...but the bubbles stopped so that can’t be right.

It’s probably 2 years old...maybe only 10 or 15 sleeps all up because a swap it out with my S2S ultralight mat. Not sure what to do with it, I kind of wish it was a unfixable giant tear and I could be done with it. I deplore waste.

Thermarest are pretty good at replacements and warranty. At the worst they’ll charge you a small fee to find and fix the leak or they’ll just give you a new mat free of charge.

[puredingo]

Does it need to go back to America? I haven’t got the receipt so that could be a problem.

I find it strange camping shops don’t offer a repair service for a fee. Most surf shops have ding repair as other industries do...maybe a money making Avenue for some go getter.

[Zapruda]

Does it need to go back to America? I haven’t got the receipt so that could be a problem.

I find it strange camping shops don’t offer a repair service for a fee. Most surf shops have ding repair as other industries do...maybe a money making Avenue for some go getter.

No, It will go to Spelean the Australian distributor and hopefully be fixed by them or most likely replaced

Phone: (02) 9966 9800
Email: [email protected]

[puredingo]

Thanks heaps for that info Stef. And than you all for your input, community values at it’s best!

[Nuts]

They can be frustrating. If so, I half inflate, enough so it's difficult but possible to roll up and sink the whole mat underwater (with a hand in either end of the roll). Then when you find the amount of air indicating your leak, unroll the mat from the water to isolate it. It can be a tiny fizzy line of bubbles but seeing what you need to focus on can help pin it down. Holes are almost as often down in a crease on the top of a mat, as underneath.

[puredingo]

The mats been sent off to Spelean...stay tuned for the action packed details of the excitement filled results!!

[Zapruda]

Cant wait!

[Kickinghorse]

Ok so it’s off to Spelean, result will be interesting. For future reference I had the same problem a while back and found the leak using one of those small tyre inflator machines that plug into a car cigarette lighter. Pumped it up to not too great a pressure but that was more than what I could breathe in. I then immersed it in the pool (bit cold at moment) and discovered a small stream of bubbles.
Seems those annoying slow leaks can only be found when the pad is over inflated.
Phil

[puredingo]

So the state of play is this.

They have received the mat, analysis of condition has been assessed and the verdict is a pin hole leak near the upper seam.

The damage for repair is $33+delivery...which I agreed to.

So the whole ordeal is it cost me $12 to post $33 for the repair and most likely $12 to get it back....Thoughts?

[Franco]

Ok so it’s off to Spelean, result will be interesting. For future reference I had the same problem a while back and found the leak using one of those small tyre inflator machines that plug into a car cigarette lighter. Pumped it up to not too great a pressure but that was more than what I could breathe in. I then immersed it in the pool (bit cold at moment) and discovered a small stream of bubbles.
Seems those annoying slow leaks can only be found when the pad is over inflated.
Phil

Thanks for that.
I had a mat with a mysterious leak (another brand) but knowing all the other tricks I could not find it . After several attempts I gave up.
BNext time I will try the overinflating trick.

[Nuts]

12v pump is good, and good for maintenance, still not enough pressure alone to find the smallest leaks, not pressured like lying on the mat (or rolling it.. you really want to squeeze that puppy).

[puredingo]

Ok, so I just got the Neoair mat back and all up it was a $60 venture including the repair and postage both ways.

Not exactly cheap but not the end of the world either. I didn’t have a repair kit so it would have meant springing for one of them and in any case I couldn’t locate the leak in the first place, so...it is what it is?

[Kickinghorse]

Great re the fix but would be very interested how they found the leak. Was it a method of “you really want to squeeze that puppy”
As suggested by Nuts?
Phil

[Nuts]

Well.. don't actually squeeze an actual puppy, maybe just gently if the frustration is too much.
I'd be interested too, if they are happy to share. Anyway, the cost sounds very reasonable.

[Orion]

I thought standing on it in the bathtub would do the trick. It's how I found a very slow leak. But apparently it wasn't the only leak so there I was standing on the Xlite in the tub again. I found another leak immediately. I went to get a pen to mark it but when I stood on it the second time there was no leak. W T F ?

It's something I've experienced before and have wondered if water somehow blocks the really tiny holes. Maybe the fabric swells slightly? I don't know.

So I folded the mat in half, which is hard to do when it's fully inflated, and stood on it yet again. Still no bubbles where I'd seen them at first. But a second, larger stream of bubbles appeared in a different place. I tried to isolate the location but those bubbles disappeared too. I spent another 10-15 minutes getting nothing, not a single bubble.

Frustrating. Been there before. Feel like these mats are kind of a scam except that they are so light and compact and reasonably comfortable once you learn how to sleep on one. I'll try again to find what I assume is at least two leaks but I'm mentally preparing for throwing it away and buying a new one.

[puredingo]

Yep, I feel your pain Orion I went through all that drama myself.

But don’t throw it, the people at Spelean were unreal to deal with. Can’t hurt to ask them a few questions and discover your options. They are super prompt and seem honest enough.

[Neo]

I had systematically placed tiny leaks in a Nemo mat. They were on some weld spots. Needed a bed so bought an Exped which later had a baffle let go six or so months in.
Got a warranty on both, passed on the new Exped, soon after the Nemo had a dodgey (twist) valve.
Now happiky sleep on an STS mat, the short yellow one.
Kudos to both Exped and Nemo and the stores involved for the warranty replacements.

[Orion]

Yep, I feel your pain Orion I went through all that drama myself.

But don’t throw it, the people at Spelean were unreal to deal with. Can’t hurt to ask them a few questions and discover your options. They are super prompt and seem honest enough.

I'm an evil American and live in California. I just by accident fell in love with Tasmania over a decade ago and have been fortunate to have had the means to visit multiple times. Of course now in all likelihood I won't be back for quite some time, who knows when.


I finally got back into the tub with my partner's slowly leaking mat. I knew there were at least a couple small holes and I was intent on finding them. I stood on the mat and within a minute saw some bubbles coming from the same spot I'd first seen, in the middle of the top of the pad, at the twelfth weld. Then, as I watched I noticed there were two sources of bubbles less than a centimeter apart. After a another thirty seconds I saw a third source about twenty centimeters away. Then a fourth in yet another location, all at welds. Then a fifth...

After I counted eight tiny holes I gave up. It was clear to me that the mat was hosed. It couldn't have been punctures. It was just "wear", as in only used in a clean tent, rolled up carefully and kept in a stuff sack when not used. Not really that many nights, a few dozen at most. She treated it like one would any very fragile but expensive item. Like a fine porcelain vase.

This isn't the first time I've had this experience with these particular mats. I think they are simply not at all durable and should be considered disposable, kind of like an inexpensive plastic razor. Except that they are most definitely NOT inexpensive.

I'm going to give my (currently) non-leaking XLite to my partner. I'm going backward to my previous mat. It's heavier, almost twice as much, bulkier, and thinner. But oh, the peace of mind blowing it up at night and not being anxious that it might fail. Even the previous iterations of Thermarest could be aggravating in terms of leaks but the XLite takes it up a notch. And they are expensive.

There's a new version, the UberLite, that is 25% lighter and presumably leaks at least 25% sooner. It's 15D fabric instead of 30D. It comes in the color "Orion" but I'm not buying it. Nope, not me.

[puredingo]

STOP THE PRESSES!!!

*&%$#! thing is leaking again. At the same rate as last time, approximately 3 to 4 re-inflations through an 8 hour night.

Don’t know wether to go through the repair process again or just start again and buy a new one? Pain in the *&%$#!...and hip.

[Moondog55]

I just fixed another one of those slow leaks.
I couldn't find it until I got a bar of soap and cleaned the whole outside of the mat. It looked clean but the water ran dark brown for a while.
Another tiny pin hole, same place but on the other side of the mat.

[commando]

Comfort versus No Risk, everyone gets a chance to decide.