Floor of my cuben fiber tent (Zpacks Duplex) is leaking. How to make waterproof?

Pitch it where water doesnt pool, or run, and it dont matter.

If it bothers you, find pinholes and put tape over

Make a big balloon, squeeze until the water leaks out, mark it, tape it. Ring Zpacks if unsure.

Well, locating the hole/holes is important. But, if you cannot, they must be very small. I would suggest a light coating of mineral spirits/caulk over the whole floor. Perhaps a 30:1 mix. Do it on both sides and wipe it down with a series of paper towels.

No, silicone does not actually adhere to silicone. But, it may stick to any pinholes by sticking to itself and forming a water resistant “plug”. I have done similar with PU coated floors. It worked fine for them, even though PU does not effectively bond with silicone. It worked fine on my old dry bag when the coating actually peeled loose, and, on an old Eddie Bauer rain jacket when the tape came off. It is worth a shot. When my Zpacks tent starts leaking I will certainly try it there.

You say you can’t see any pinholes, have you tried holding the floor in front of a strong light?  Once identified, the cuben repair tape that ZPacks sells works beautifully as a permanent repair.

I have a Duplex purchased in Nov 2013…just weeks after they went on sale.  I have always used a 3 oz DIY polycro groundsheet and the floor looks and performs as new.  Perhaps the use of a groundsheet would mitigate the now leaky floor?  Check out the double-thick sliding patio door film sold by Duck…I got it at W*l-M*rt.

Thanks for the suggestions and encouragement.

On a 3rd try I was finally able to locate some (all?) of the pinholes and patch them.

The floor of the duplex being translucent made finding of the pinholes by shining a light from the other side of the fabric hard. Shinning a bright light held on the other side of the fabric did not  work. What worked for me was

• setting up the  tent in my garage
• turning on the garage ceiling light
• Crawling under the tent and looking for bright spots (diffuse ceiling light showing through a pin hole)

Peter

Not to be a hater – I like cuben – but it just isn’t a good material for floors. It regularly develops pinholes because it has very little abrasion resistance. Once they start they’re just going to keep happening.

I don’t understand why manufacturers are still building floors from cuben. Zpacks is using the 1.0oz stuff for the floor (at least they’re not using the 0.5 – 0.7oz stuff with much thinner mylar) but you can buy woven materials that weigh about the same or slightly more which last much better, pack smaller and are much cheaper. You can get a nice 15D nylon or poly for 1.0 – 1.2oz/yd (so an extra 0 to 0.5oz on the entire tent) and this would save about $100 off the price and not have this problem.

So in your circumstance, I’d either just live with new pinholes as they continue to develop and try to avoid pitching on saturated sites, or if you want a waterproof floor then grab a few yards of a different material and find someone to sew it in.

I don’t understand why manufacturers are still building floors from cuben.

+1

I’ve got hundreds of nights on my duplex and I don’t see the cuben floor as a problem. I’ve also owned cuben hybrid packs and I agree the material doesn’t stand up to abrasion well. Even camping in the alpine the majority of the time, I just don’t think tent floors see that much abrasion, since they pretty much stay in one place.

Traditionally when this happens with any tent—sponging water up thru the floor from the ground—most especially when body weight is applied on top of the floor on saturated ground—it’s time to get another tent.

I’d look for a tent with a higher hydrostatic head like 7,000 or 10,000mm for the floor material.  And do this backyard test—

Fill a grassy depression with water from the hose, place tent floor on top of puddle, sit on floor with your butt for 5 minutes—see if any water comes thru.  Yes or no.