Large, ultralight rainfly

Your question is a bit confusing to me. Are you looking for a tarp or a rainfly for an existing shelter? I’d think most rainflys are specific to the shelter they’re made for — just any rainfly wouldn’t necessarily fit your shelter.

A rainfly for a hammock. Maybe it would be called a tarp?

Yes, that would be a tarp. Now we’re talking about cost being a major factor, so it depends on how much you’re willing to spend. Cuben tarps are lighter than silnylon or silpoly tarps, but much, much more expensive. I can’t explain sil vs silpoly as I’ve never bothered to have a level of interest to go down that road.

If I were going to buy a hammock tarp, I’d look at zPacks, Hammock Gear, and Mountain Laurel Designs (MLD). There are others, those are just the ones I generally go to first.

Not as much help as you’d like, but it’s a start, and folks who know much more about materials and such will probably chime in to give a better answer.

Thank you. I was just reading on “dyneema cuben” tarps which might be what you’re referring to? Cost isn’t a factor right now since I’m not buying right away, just researching as thoroughly as possible while saving.

Do you own a cuben tarp?  wondering how they hold up over time

Yes, more than one. Others will hopefully chime in, but from everything that I’ve heard, cuben is an exceptionally strong material (I think it was first used on large sails) who’s main kryptonite is abrasion, which shouldn’t be an issue when used as a tarp. I’ve never had any issue with my cuben stuff (tarps and shelters, including shelters with cuben floors, as well as stuff sacks and such). So mine have held up just fine. I never ‘stuff’ cuben though, that’s generally advised against, I roll/fold before putting anything in a stuff sack.

But n=1 isn’t perhaps the best thing to base a decision on. :-) I can say that there are a lot of people out there who have been using cuben for quite some time now, and continue to do so.

Lots of companies make hammock tarps. A lot of tarp people like asymmetrical tarps for their hammocks, or tarps that aren’t perfect flat rectangles. Some of them have doors or strategically placed loops for hanging things.

I believe the difference between silpoly and silnylon is that one is polyester and the other is nylon. Polyester supposedly does not stretch as much when wet as silnyon does. Both are impregnated with a silicone treatment that makes it impenetrable to water. Both fabrics are somewhat more durable than DCF, but DCF is durable when used for a tarp.

So is all cuben fabric 4 seasons? Or is there a coating it needs or a “grade” I’d need to look for?

I’m also not worried about abrasion for any tarp I buy, mostly because of the way I’d use it. Though it looks like they make hammocks from the material too, which seems like it might be a bit abrasive in the long term

“Cuben” = “Dyneema” = “Dyneema Composite Fabric” = DCF.  It is light, very strong for its weight, waterproof, and more expensive.  It comes in different weights and the lighter weights are (lighter, duh, but) not as durable.  People report DCF tents like Zpacks’ Duplex last about one thru-hike (120-150 nights), although tents probably see more wear/night than a DCF hammock tarps do.  We backpackers don’t spend enough money to drive the market – the deeper pockets are competitive sailors who want very strong, very light-weight sails but that has created fabrics that backpacking cottage-industry shops have turned into tents, tarps and packs.

DCF is a composite (the C in DCF) of ultra-high-molecular-weight polyethylene laminated between two sheets of polyester.  Some describe it as “inherently waterproof” but so are many composite fabrics, as an assembly.  DCF is notable for not absorbing water into any of its component parts. DCF is noisier in the wind and rain than silnylon.

Silnylon is now used in lighter weights than the urethane-coated nylon of decades past but tends to be heavier, cheaper, and sturdier than DCF.  If you haven’t been backpacking before or for a few decades, silnylon will seem remarkably light for what it does.

Ahh, spell-check converted that to “Lutheran-coated nylon”.  Sorry, Catholics.

I’d suggest starting with size (more coverage will keep you dry in worse weather) and weight versus cost (sometimes saving that last ounce is another $100).  And among your top contenders do a deeper dive on their durability and other user experiences people have reported.

I have a Hummingbird Hammocks Pelican tarp.  It’s made of 0.9 Silpoly so it’s very lightweight (12.8 oz.) but is somewhat fragile.  Mine ripped all the way up the sidewall to the ridgeline and I had to do a field repair with some needle and thread on my last trip.  Cuben fiber or DCF is strong and light but very expensive.  Hammock Gear makes a Silpoly tarp called the Journey with doors as well that is made with 1.1 oz. ripstop so it’s a little more durable but slightly heavier at 15.46 oz.  I like the linelocs on the tie outs.  Hammock Gear also makes a Dyneema version that is half the weight but more than twice the price.  It’s nice but pricey.  If cost isn’t a factor I’d go with the Dyneema for the weight savings personally.

Reading thru, it appears you’re basically looking for a large hammock tarp w/ doors, less than 1lb, right? That narrows things down and Andrew has listed a couple good options. I’m almost exclusively a hammock camper and have been dialing in my tarp setup lately so here’s my two cents to maybe help fill in any gaps or affirm others comments.

for most hammockers, “large” (or full coverage) basically means a hex tarp w/ doors or a square tarp that’s st least 9’x9’. so you can ignore smaller rectangular tarps, asym diamond tarps, standard hex tarps (no doors), etc. A hex tarp will be best for a beginner as it’s very straightforward to setup. A square tarp will give a few more pitch options though.

At that larger size, it’s gonna have to be a lighter material to stay under 1lb. Any tarp made w/ material heavier than ~1.3oz/sq yd will be more than you want. The lightest waterproof materials are DCF at .51oz/sq yd, silnylon is ~.7oz/sq yd, silpoly is ~.9oz/sq yd. Others have described those already so I won’t again.

There are a lot of vendors who sell hex tarps w/ doors in lighter weight fabrics. In addition to Andrews list, there’s Dutchware, Simply Light Designs, Zpacks, MLD, Warbonnet Outdoors, etc. Most have square tarps also but one that doesn’t sell hex so not mentioned above is Hyperlite Mountain Gear. Peruse their sites and make note of material vs weight vs cost as they vary substantially. Cheapest 1.3oz sq tarps could be 1lb and $50. Lightest hex tarp w/ doors in .51DCF are 10oz and ~$350.

Side note, the lightest sil-materials get complaints of not being quite 100% waterproof as users experience “misting” underneath them… many believe this is actually just condensation being knocked off by the rain droplets but I haven’t seen anything definitive.

hope that helps point you the right direction.

Just a couple of observations. 1) Misting is real, I had a BD silnylon pyramid tent that worked great for snow camping but during heavy rain, everything inside eventually got wet.

2) See the MLD blog about fabrics. https://mountainlaureldesigns.com/mld-pro-silnylons-vs-cheap-china-counterfeits/

3) One potential drawback of cuben fiber (aka dyneema) is that it takes up a bunch more room in your pack (or on the outside of your pack than the same sized silnylon shelter

4) If you expect snow or hail, do not buy the thinnest fabric shelters be they dyneema or silnylon

You can “repair” silnylon tarps/ents that are so lightly coated they mist-thru. Choose 2 days of clear, warm weather to do this.

MATERIALS: 1.)one quart of “odorless” mineral spirits  2.)one tube of clear GE silicone caulk   and caulking gun  3.)small (6″) low knap paint roller  and tray  4.)large peanut butter size (clean) mixing jar W/ lid  5.)roll of blue heavy duty paper “shop towels”

PROCEDURE: 1.) mix 5 parts (by volume) mineral spirits and 1 part clear silicone caulk in closed jar by shaking well for 2 minutes.  2.)pour some mix into the small paint tray  3.)soak roller and roll out excess coating  4.)roll on a tautly set up tent in 2 ft. X 2 ft. sections and, using the shop towels, WIPE DOWN IMMEDIATELY  5.) continue, overlapping coated areas a bit until finished.  6.)let dry for one or two days depending on outside temperature.

Coat outside of the floor the same way. Apply more coating later to entrance wear areas.