Beginner Tarp Size for Two/Borahgami?

First off pat your self on the back for even consider getting into tarping ( defiantly one of my favorite techniques adopted). As far as size of flat tarp I would think that the 9 by 9 would be very comfy at 81 square feet of coverage for 2 people and there gear. You can always give it a nice low pitch in real stormy condition's or supplement it with some natural cover. I have found that square tarps are easier to pitch at different angles that being said The a frame pitch is the one that you will probably be using 80% of the time. Just ask your self "what conditions are we mostly going to find our selfs in?", and what your style of backpacking is . Are you more likely to hang out on a rainy day in the shelter or push on regardless, if you think you'll be hanging out more I might go with a bigger tarp. A great way to get a feel for size and pitch of flat tarp is to go pick up some 2 or 3 mm painters drop cloth and make a poly tarp. I do this for testing out various sizes of tarps just use some duct or gorilla tape to make tie out points and some masons line for guylines. As far as the Borahgami goes, I have no experience so I can not say, but to me it just looks like a really complicated tarp and one of beauties of tarping is that it is simple. But what ever you chose I do not think you can go wrong with a tarp shelter the benefits are immense.
Happy Trails
Matt

I believe that shelter style/design is all about the weather. Any shelter works well when the weather is good, the real question is how well does it work in the worst weather you reasonably expect.

In the SE US, we often have very strong thunderstorms that can pop up in less than an hour…my grandfather called them "toad stranglers". Very heavy rain and strong, swirling winds. In these conditions I have found tarps problematic. Not being able to predict wind direction means that in a shelter without doors there is an extremely good chance of getting wet. I have since moved to a ZPacks Duplex and am not looking back but, were I to consider tarping again, I would be all over the Borahgami as it appears to solve the issues I had with tarps and wet weather. In fact, if that had been my first tarp, I just might still be tarping.

Yup, I agree a 9×9 is probably about right.

You want the 9' length for rain. In low pitch mode, the peaks sit about 30" high. Spray from rain can penetrate at roughly 45 degrees or about the same distance. Drip spray will usually penetrate about 6" on each side, given the tarp is on level ground. So, 9' is correct for length to stay dry.

On the sides, allow 6" for runoff and I figure about 44" for two people. Or, roughly 56", minimum (in the ADK's.) So, a 7' figure is about right for full coverage. So a 7'x9' tarp in A frame will cover two people as you described without getting wet. You might need a couple sticks to keep you feet from rubbing on the tarp.

If you can tolerate a little spray, or, dampness, reducing this can save a bit of weight. If you have a constant wind direction you can go a bit shorter, etc. Using every trick to slow down, but not fully stop rain/spray/splash-back, you can go with a simple lean-to, getting it down to about 6'x7' assuming a 44" sleeping area. This is rather tight and not something I would do on a regular basis, ie, if two or three nights of rain is anticipated. You might consider a larger plastic garbage bag for the feet.

A square tarp will give you a few more pitching options, but it is possible to use whatever pitch with a rectangular tarp. I like my 9'x9' with my wife. It keeps us very dry and gives us room for cooking under when things get wet & cold. Solo, I use a 6'x9' shaped tarp that weighs about 16oz after recoating with silicone calk/mineral spirits. This is about 10-12 years old. I can actually fit my wife or a partner under it, but my wife complains about it being so open. It is also difficult to use at campgrounds.

I'm new to the tarp thing too. I bought a silnylon 8 x 10 on the gear trader forum for cheap to set it up a couple times and see if this was something I wanted to pursue. After trying several pitches in the back yard I did one night in the wilderness and was confident enough to spend the big dollars on a cuben flavor, same size.

You don't pay much of a weight penalty for a slightly larger tarp. I considered a shaped one but the flat one gives you more flexibility and while the bat wings are cool, the flat version really does everything I need it too.

I'm using mine solo but there is TONS of room under there. I'd have no hesitation adding a second person.

I've identified two pitches that I'll use for sleeping. The A-Frame for good weather and the pyramid where you essentially drop one side of the A-Frame and stake it to the ground in storm mode. I've also experimented with pushing my second trekking pole under the back side in storm mode to give more headroom. There is still tons of space coming from a tent.

Thanks for the help. The 9×9 sounds like the way to go, I'll skip the Borahgami for now.

Sounds like you've made up your mind but my recommendation would be a 9×9 or 8×10. For me, I prefer an A frame over other pitches. As mentioned, I'd go with a relatively inexpensive silnylon one for the time being before spending more money on cuben.

If you're concerned about privacy, the Borahgami is a nice option.

The Borahgami is much like a traditional flat tarp with shaped tarp options. You get the closed ends to add weather resistance, but you can open it up for better weather and ventilation. It's a a good balance of weight, space and cost. My guess is that most flat tarps users go for a lean-to or a-frame, which the Boragami does well. It does have the same wind issues as any flat tarp.

The Borahgami is light enough that it still works for a spacious solo shelter or a solo+dog rig.