Introduction: No-Sew Spandex Tensile Shade Structure

Too much sun? Make yourself some shade! This instructable comes from an idea I had about a way to make simple, fast, and cheap shade structures out of spandex (Lycra) fabric. This method lends itself to experimentation since it doesn't require sewing or permanently altering your materials. It'd be great for a temporary display for an event that needs a splash of color and some relief from the sun.

Step 1: Tensile Structures

There are two main categories of forces that a material can experience: tension and compression. Think of tension as a pulling force and compression as a pushing force.

Most permanent buildings are made of materials that work well in compression, like brick and concrete. The weight of the building itself and the stuff inside it push down and compress the walls to keep it standing. Buildings that are made of compression materials are usually heavy. The Romans used a lot of stone. They were fans of compression.

A structure like your average camping tent works via tension - the space is enclosed by fabric that is stretched between a lightweight frame. You put stakes in the ground to pull on the fabric so it stays more or less in the same shape. When you think tension, think ropes and fabric. Some of the best rope-structure builders were the Incas. They built suspension bridges that spanned canyons and terrified their European visitors.

Wikipedia will tell you more about tensile structures.

One of the advantages of tensile structures is that you can span a very large distance without using a lot of material. This is why the longest bridges in the world are suspension bridges with a deck hanging from cables in tension.

Step 2: Materials

You will need:
  • Spandex Fabric - This is the tight-fitting stretchy stuff that swimsuits and cycling clothes are made of. Your local fabric store should have some. Get enough to cover the area you're looking to shade. I bought 9 yards for the structures you'll see in the pictures and it cost about $40.
  • String - A spool of medium gauge synthetic string from a hardware store should work fine. Avoid cotton; it'll break down in the rain and sun.
  • Zip ties - Part I of the super secret no-sew connection system. A pack of 100 short (3") ties will do. Look for UV resistant ones - they're usually black.
  • Pennies - Part II of the super secret no-sew connection system. Go to your bank for a roll, or break open the ol' piggy bank. A dollar's worth will do.
  • Scissors - If you want to cut your fabric into different shapes (optional), you'll need some scissors. These will also come in handy for clipping the ends of the cable ties to make things look neat, but a pair of nail clippers or wire snips work better for that.
  • Extending curtain rods (optional) - If you want to push the fabric up where there is no existing support, a curtain rod works great. You can get twist-locking adjustable ones at a hardware store. Extending paint roller poles also work well, and they're useful if you take the structure down. Other non-adjustable poles will work and are cheaper, but they're harder to experiment with.

Step 3: Play Around

Stretch that fabric! See how it behaves, how far you can stress it, how much force it exerts, what shapes it takes etc.

You'll notice that the fabric never takes on a form with straight lines. It also never will be completely flat. In fact, the flatter the fabric is, the more it will flop around with the wind. The best forms for tensile structures are ones with double curvature - which means the fabric is bending in two different directions (a dome and a classic circus tent both have double curvature, a vault has single curvature).

Do a Google image search to get some ideas on forms you can make. You'll see that the physics of working with this kind of material lead to a certain style of structures - no boxes or straight lines allowed!

Step 4: Reinforced Connection Points

After playing around some, you probably realize the best way to shape your fabric is by pulling on it. To free up your hands, you'll probably want to tie it back in various places. Usually a tensile structure's fabric will have sewn-in reinforced connectors or grommets for wires or ropes to grab onto. These stop the fabric from ripping due to a concentrated force from the rope. Think of the metal grommet holes in a tarp or on a flag.

Putting in grommets is an option, but it's tough to do in stretchy fabric and it requires permanently altering the pieces you have. Instead, try this:
  • Take a penny and push it through a corner or edge of the fabric
  • Twist the penny to make a narrow "neck" in the fabric
  • Cinch a zip tie around this neck, trapping the penny inside the fabric
  • Tie a piece of string around the fabric neck.

The penny should stop the string from slipping off even if you pull on it very hard, and since you didn't have to cut the fabric you can pull much harder before it rips.

That's the secret. Simple, right? You can even use this to connect two pieces of fabric together, like a stitch (as shown in the pictures).

Step 5: Stretch, Tie, Experiment

Try tying the fabric to different structures around the area you want to shade. Trees work well, as do fire escapes, pipes, or other things sticking off nearby buildings. Since the fabric is mostly hanging from these things, you'll want to find some supports that are high up, but try bringing it down to the ground as well.

If you want to take the fabric in a different direction, just add in another connection point! Try to keep the whole piece taught - it will flop around less - but you might have to relieve the tension some to push another penny through.

Step 6: Push It Up

If you need to raise the roof in a spot or two, use your curtain rods or adjustable paint roller poles to push up on the fabric. The elastic fabric will push back and hold the rod down to the ground without any additional support if you push hard enough. Try this in the center, edges, and corners of the fabric. You can also run the string over a pole to make a high tie-back point.

Step 7: Add On

Connect different pieces of fabric together to extend your structure and make different shapes. No need to sew the pieces - just connect them with pennies and zip ties at a few points. The more "stitches" you use, the smaller the gaps between the fabric will be, but there will always be some space. I think it looks nice that way! Who needs straight lines?

Step 8: Enjoy the Shade

Keep playing until you've got something you like that shades the area you want. Remember that the position of the sun will change, so keep in mind where the shade will be at different times of the day.

Then sit back and enjoy the shade!

Comments

author
trrydms made it!(author)2014-03-17

genius.

author
FractalQueen made it!(author)2014-03-02

Has anyone tested this method out under high winds? I'm looking at making my shade structure for burning man from shade sails, but I worry about the penny method under extremely high wind conditions. I know that sewing in grommets will end up making the fabric rip, unless I go with parachute materials or something. But this method looks super easy, so I'd like to try it first.

author
Shela made it!(author)2012-11-18

Sweet, I love it.

author
Thraeryn made it!(author)2011-08-24

I hope to do this very soon! I'm curious as to any tricks you may use to lash the fabric to the longer supports. (I have no idea what I'll have available to which I can tie, aside from poles.)

author
Valster made it!(author)2010-08-26

Great idea! I can't say I'm going to do it this year but it will definitely go in my favorites for future reference. How about durability? Do you put the shades up only when needed or leave them up for the summer? I laughed when I saw that you were using pennies. I immediately thought of using washers instead 'til I realized that pennies were cheaper!

author
valhallas_end made it!(author)2010-01-23

Interesting...I wish I had seen this sooner - we've been looking at shade sails, but decided the hardpoints necessary and the sails would be too expensive, so we went without.  This might be something to test in the spring.

author
Valster made it!(author)2010-08-26

I could have written your reply. I even bought sunbrella fabric to try to make my own. It's collecting dust in the basement.

author
kronick made it!(author)2010-01-23

I'd love to see what you make if you do experiment with this. Please post pictures!

author
valhallas_end made it!(author)2010-01-23

Definitely.  Out of curiosity, where did you buy your spandex?  We have no local companies that carry Lycra in large enough rolls, and the internet had far too many clothing sites to sift through.  I found a few with raw material, but only in skinny strips or truly hideous patterns.

author
kronick made it!(author)2010-01-23

I got mine from a local discount fabric supplier (specifically http://www.sewlowdiscountfabrics.com/). Usually you'll be able to find a place that carries mill ends or leftovers of lots of different fabrics for cheap. Usually they're very unorganized and you'll never know what you'll find. I'd recommend finding a place in person so you can feel what you're getting. Short of that, you might try eBay.

author
rose.yell made it!(author)2010-05-03

So inventive, really clever!
Really have to try this one!

author
prank made it!(author)2009-10-01

wicked cool, sam-o

author
l8nite made it!(author)2009-09-30

They really do look cool and remind me of what my dad did when camping (or just a picnic) He had an old sail from a long gone sailboat and he'd tie it to trees or other convenient posts

author
MrGreggan made it!(author)2009-09-30

Very clever use of spandex. Here's a company that makes similar structures:

http://www.pinkincdesign.com/

author
rimar2000 made it!(author)2009-09-30

This shape is really beautiful

author
kronick made it!(author)2009-09-30

Glad you like them! I wish I could claim them as my design, but these forms come directly from nature and the physics of using materials in this way.

If you want to see more natural shapes like this, check out Felix Candela and his work in concrete - it's based on similar principles.

author
lafnbear made it!(author)2009-09-30

Love the non-permanent, nomadic nature of this idea! Also, a practical side-benefit of the gaps between fabric pieces: wind passes through the gaps, so it relieves wind pressure against the fabric itself (ever see commercial printed ad banners with semi-circles cut into them? Same principle...)

author
NE-Phil made it!(author)2009-09-30

Love it! A very clever instructable.

author
SeamusDubh made it!(author)2009-09-29

Now that's quite simply brilliant.

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