How much overhang is "safe" for a tarp over a gathered end hammock? I was in 30+ mph winds and rain and stayed dry with a cheap 10' x 8' tarp on a diagonal over a 10'5" hammock. Still, I was worried all night because of the wind and rain.
I'd like to move to an 11' hammock. I have a 9' Kelty Noah which I'm sure will cover it but if I wanted to make my own tarp to cut down on weight what size do I really need?
Mheinze tarp size is your preference. I think I'd need the tarp ridge line to 1foot longer than hammock ridge line. This gives you a theoretical overhang of 6inches on both sides--I say theoretical because no hammock is exactly centered under tarp. Six inch overhangs can benefit greatly with doors that close on both ends. Longer overhangs with guy line loops in the right places can allow tarps with no doors to be "closed"during rain. That's my preference-that way I don't have real doors to fold back when not in use. Overhang length is also influenced by tarp style-diamond, hex, asymmetrical and Aframe. If some mist is getting in--underquilt protector and a poncho or two hanging on hammock ridge line will help; along with lowering tarp and or raising hammock so that tarp ridge line and hammock ridge line are almost the same. In the end I all depends on you. Good luck Mheinze.
You will need exactly enough to protect yourself and your investments, to remain dry and warm. And this can range from 2 inches plus or minus the distance between tarp and hammock X's .36 inches per degree of angle of precipitation at a height declination of -2 degrees per mph/hr. This does not take into the strength of material or the supporting trees (sag); assumes that tarp is in close prox to the hammock; orientated and centered above it.
so for example if you have 30mph winds and rain is at a 90 degree angle (sky being 0) and the tarp is 2 inches above you will need 2.7 feet of overhang pitched 150 degrees for 0 chance of wetness (this assumes that the girth of you will fit into the 60 degree's of angle at a safe hanging distance from the ground) and is added into the calculation.
now you will have to determine the shape of your tarp and factor those angles in to assure coverage.
I use a full coverage tarp (SF from WB) with doors and I never worry about it. Good luck.
“ Do not correct a fool or he will hate you, correct a wise man and he will appreciate you.”
~ Bruce Lee
If you have your ridgeline at 83%, your 9' kelty won't be long enough. I wouldn't save that much on tarp coverage. You said it yourself: you were worried all night. You probably would be good with slightly more than 9' as a tarp and pitching really low. I have an 11' tarp and I wouldn't mind upgrading to 12'. It just allows for more room. If you are worried about weight, you could try for a cuben fiber one...
You might want to check with Etowah Outfitters, they have some good light weight silnylon tarps that are lighter then the Kelty and weights are around the same.
I refuse to be old! Life is too short to sit on the couch!! Let's go hanging!!
There are a lot of tarp users out there that rely on tarps with minimal coverage. However, I live in a coastal area where the winds are extremely variable. I've camped from upstate NY down to Virginia, and the winds just don't seem to understand that they shouldn't shift, and the campsites I select just don't seem to be aware that I'm using a tarp that may not be adequate for shifting winds.
Therefore, I almost always use a tarp with doors, and stay dry as a bone without having to rely on site selection or pitching the tarp really low to stay dry. I especially don't like tarps pitched in a diamond configuration, because way too much wind gets under the tarp, turning it into a windsail.
I think it all comes down to what you've experienced - if you never got wet then wind variability of 80% probably makes perfect sense. However, I have gotten wet, and don't want to do it again. Doors for me.
"A foolish consistency is the hobgoblin of little minds." Ralph Waldo Emerson
I currently use the Kelty 9 in the diamond configuration so the tarp ridge line is nearly 13 feet - plenty of coverage. The smaller 10' x 8' in diamond-like (asym) configuration actually kept me dry in 30+ mph winds.Originally Posted by Kvothe
I can see some advantages to doors but I also really like that I can get by with just 2 stakes in the diamond configuration. I just can't seem to visualize how far past the end of the hammock I really need to go (especially since I stayed dry with the shorter 8x10 tarp). I've seen 6 inches several times in posts but I wonder if that just applies to hex/a-frame configurations with doors?
I do backpack so weight matters but being dry is even more important and of course cost is a factor. Maybe I should just switch to hex (+doors) and it becomes easier to figure out... :-)
Unfortunately, that exceeds my maths skills (or time to figure it out), but you could draw it up and calculate it. What angle will the rain get at what wind speeds, sag of the hammock and then you could calculate the exact amount of overhang needed.
OK, I had to read this 4 times! LOL
Is this a bit conservative? I had about 1.5 feet of overhang with the 8x10 tarp and stayed dry. Of course the rain was not 90 degrees but it was "somewhat sideways" and the winds gusted over 40 mph at times (although mostly a steady 25-30 mph). The wind was coming off a lake and up a hill so at times the wind could actually be greater than 90 degrees. The tarp pitch varied as the wind hit it but I was not pitched at 150 degrees and I rarely felt any wind.
Some mist did get on the bottom of the hammock after several hours but nothing significant.
I guess I could convert to a different design but I really am curious about coverage with a diamond configuration.
With "full coverage" do you just go with 6 inches of overhang?
Thanks - that makes sense. The back side of the 8x10 tarp did billow out in the wind but fortunately the wind never shifted in a direction that got me wet.
How much overhang do you have on the tarp with doors?
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