Why not seamless tarp?

**StellaTerra** · 05-20-2016, 13:22

Looking around at some of the non-breathable materials available, my brain started working and I got to thinking, is it unreasonable to try to cut a tarp from an extra-wide piece of material, and hem the edges, but have no ridge or other seam?

I did some math, if there was a 72" wide material, and we're making a diamond tarp, we could cut a piece that is 11' long on the ridge, ~78.75" on each side with a tip-to-tip span of ~86". The total area would be ~4.4 sq yards, and if the material weighed 1.1 oz/sq yd, it would weigh less than 5 ounces without lines or tie-outs. Probably all-told around 6 oz. It would need just over 3 yards of material, so cost would be for 4 yards of whatever it was.

I am very inexperienced with hammock camping, for those of you who have done this more, is that a reasonable size and design? Other than hemming and attaching tie-outs, this just seems like an super simple approach, and I'm wondering why I'm not finding any pictures of people doing stuff like this.

**pgibson** · 05-20-2016, 13:49

There are a few shops that make a design along those lines. Most refer to them as Asym diamonds....should help in the search. Just keep in mind that they are narrow and give you fair weather coverage....setting up out of the wind in areas that are more sheltered can help should you get sideways blowing rain.

**Double** · 05-20-2016, 13:54

Most of the newer lighter material comes 58 inches wide. That combined with wanting more coverage that a hex or "winter" tarps provide means a seam is necessary. You can make a asymmetrical trap out of 58 inch material and not have a seam and a bit more protection. All up to what suites the person's needs.

**geneaut** · 05-20-2016, 13:58

Look up asym diamond tarps. I think this is what you are describing.

DIYGS-UL-Asym-Tarp-2.jpg

**StellaTerra** · 05-20-2016, 14:05

Yeah, my issue with Asyms is that they are... well... asymmetrical. I just started finding materials that were wider and I was doing math and realizing there with a wide enough material, and symmetrical diamond would be possible without a seam. I live on the west coast, we don't understand the concept of water falling from the sky as it only seems to come once or twice in a decade. An exaggeration, but even if I went with a seam, I would probably prefer a symmetrical diamond rather than a hex. My goal is looking at wider materials was to figure out if I could make a tarp with better coverage than an asym, but still without a seam. That's the question; why don't people try this?

**Boston** · 05-20-2016, 14:17

The symmetric diamond you are proposing is basically cutting down an asym tarp to make it symetric. Why? You're simply reducing coverage to an already pretty minimal design.

The man reason no one does this is material waterproof enough to make a tarp isn't available in 72" width. What material are you looking at, and are you planning a diy coating?

I think you might be confusing "non-breathable" with waterproof.

Also, generally most prefer more coverage than a diamond. The trend over the years has been away from small and light. A tip to tip width of 86" is only ~3.5 ft.

The other issue I see is you'll be pulling the tarp along the bias of the fabric, and it will stretch a lot more, making it difficult to make the tarp taut. This is part of the purpose of the ridge seam: to provide stability.

**StellaTerra** · 05-20-2016, 14:37

Originally Posted by Boston

The man reason no one does this is material waterproof enough to make a tarp isn't available in 72" width. What material are you looking at, and are you planning a diy coating?

I think you might be confusing "non-breathable" with waterproof.

Also, generally most prefer more coverage than a diamond. The trend over the years has been away from small and light. A tip to tip width of 86" is only ~3.5 ft.

The other issue I see is you'll be pulling the tarp along the bias of the fabric, and it will stretch a lot more, making it difficult to make the tarp taut. This is part of the purpose of the ridge seam: to provide stability.

Boom. Question answered. /thread. Thank you.

**Boston** · 05-20-2016, 14:48

Originally Posted by StellaTerra

Boom. Question answered. /thread. Thank you.

Well, so much for discussion.

Can't help but feel this is a bit of a rude response to someone who took the time to answer your question.

**StellaTerra** · 05-20-2016, 14:53

Originally Posted by Boston

Well, so much for discussion.

Can't help but feel this is a bit of a rude response to someone who took the time to answer your question.

???? I'm so sorry, I meant that seriously. I meant... like you totally nailed it, you answered the question of why people don't do it. I'm so sorry. ;_;