Permeability of shade structure

beaublumberg · Post by **beaublumberg** » Fri Jun 19, 2009 12:31 pm

Howdy y'all, I'm a virgin this year and I had a little plan to make a lean-to against my car with some shade cloth and put my tent under that. My question is what % shade cloth is enough? I know that a higher % will result in more shade, but would say a 60% black shade cloth still keep me from boiling? Or is it pretty useless to go for something below 80%? (I'm making these numbers up really, I have no benchmark to go on and couldn't find much info here besides other people's plans which all seem to be 70%-90%)

Thanks!

Fire_Moose · Post by **Fire_Moose** » Fri Jun 19, 2009 1:25 pm

Heavy duty silver tarp

phil · Post by **phil** » Fri Jun 19, 2009 1:27 pm

It's a judgment you'll have to make based on your experience. Of course, you won't have the experience till after you've been. :->

I use a reflective tarp that prevents 100% of the infrared and all other rays from coming through. Although UV gets all the press and causes sunburns, IR is what makes you hot.

Many people survive with 60% or whatever and don't appear to suffer. You'll get all kinds of feedback, but it may nor may not apply to you.

Remember though that if you double 60% shade cloth you get 120% shade and you'll end up with ice in your tent.

EspressoDude · Post by **EspressoDude** » Fri Jun 19, 2009 3:50 pm

Center Camp uses 38000 sqft of 80% shade cloth

swampdog · Post by **swampdog** » Fri Jun 19, 2009 4:02 pm

I've used 50% white shade cloth and (I think) 80% black. The 50% white wasn't adequate. Shade cloth is nice because it lets breeze thru. I don't really see a benefit to using a lower level (I only used the 50% white because my campmates wanted white and it doesn't come any higher).

beaublumberg · Post by **beaublumberg** » Fri Jun 19, 2009 4:57 pm

Great, thanks for all this. I'm now thinking I may double-layer it (not sure if I'm gonna leave space between the layers, any advice on this?) with a 60% black on the bottom and a 50% white on top. That way, if I touch the black cloth when I'm under there, I won't leave behind a layer of skin. All in all, I was planning on attaching one side of the cloth(s) to the top of my car, then running it down and using some poles to prop it up about 30"-36" and put my tent underneath, kind of like this:

http://www.flickr.com/photos/29671287@N08/3641906185/

Having never done this, I'm going off of nothing but intuition...anyone ever tried something like this? I was going to try to plan it so the wind would run up the shade cloth...think 30" is too high for this?

Again, thanks for all the help. This is such a great resource...I can't wait to get some experience so I can pass it along myself!

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swampdog · Post by **swampdog** » Fri Jun 19, 2009 5:12 pm

Shade cloth doesn't get very hot - don't worry about 2 layers, I'd just get one higher % layer.

Your design looks fine, but of course the devil is in the details. How are you going to attach to your car? How are you going to attach to the poles? How are you going to attach to the ground?

Since it's porous, the shade cloth is less vulnerable (not invulnerable!) to wind.

I'm a big fan of what I call "quonset" style shade structure - dead easy to set up, fairly wind proof, and pretty inexpensive. I've got to run, but I'll post more on it later. You basically make a row of half circle hoops with PVC pipe, attach a spine of pvc down the middle to hold it together, then cover with shade cloth.

gyre · Post by **gyre** » Fri Jun 19, 2009 7:24 pm

Phil, what kind of material are you using?
I think it's better to block the light and heat.
Venting underneath with stack effect is ideal.

The aluminet webhouse indicates that 80% cloth does NOT block 80% of heat and light.
They make 100% solid aluminet, but it is not imported to the usa.
Silvacool may be the same.
Reflectix has a scrim.

Mirror window film can be close to full ir blocking.
Not sure if it will hold up by itself without lamination.

The benefit to shade cloth is not retaining rainwater so it can be mounted level.
Rain may not be an issue on the playa.
Useful on a trailer, etc in the default using minimum support since water isn't an issue.

gyre · Post by **gyre** » Fri Jun 19, 2009 7:28 pm

Porous shadecloth over a solid material works if it is difficult to vent heat from under the first layer.
Leave a gap between.

A second layer of shadecloth or solid can act to block radiated heat from the initial layer and lower body heat, especially in a low cover.

Rusted Iron · Post by **Rusted Iron** » Fri Jun 19, 2009 7:30 pm

I agree with the idea of letting a breeze through. Without it, you can trap hot air in your shade area.

Keep in mind, if you attach it to your car, it's going to clank against it, in the wind. Noisy and paint scratching. You may want to put some kind of padding between the two.

gyre · Post by **gyre** » Fri Jun 19, 2009 8:00 pm

Good point.
Try to go all rigid or all flexible.
All flexible will withstand anything but the noise can be annoying.
The car will be rigid.
Wear can be an issue off the playa with car covers.

phil · Post by **phil** » Fri Jun 19, 2009 10:18 pm

gyre wrote:Phil, what kind of material are you using?
I think it's better to block the light and heat.

It's the classic silver tarp, but we also have a shade with a white rubberized canvas roof which is also absolutely sun proof.

The benefit to shade cloth is not retaining rainwater so it can be mounted level.
Rain may not be an issue on the playa.

Sometimes it is. Our white canvas shade is flat, and we came back after a shower on the playa one year, and it had collected enough water to sink about a foot in the middle. That's when we went to the peaked roof style.

We have side panels on two sides so that we have air flow all the time. The photo above shows a side panel down, which provides shade underneath the roof. There is no heat under the roof with either the silver tarp or the white canvas one; just doesn't happen. You can touch them and no heat at all. It's ambient temperature under the shade.

rodiponer · Post by **rodiponer** » Fri Jun 19, 2009 11:05 pm

Our 90% black shade cloth arrived yesterday. I am a little disappointed, it does not block the sun as much as I expected. The weave is very tight, but the plastic fibers are thin and transparent in many parts of the knitted pattern, so a lot more visible light gets through than you'd expect from either the "90% name" or the photographs on the web. I think more UV light is blocked since plastic absorbs that better. So I would not get anything less than 90% if you are looking for a deep shade. It's completely opaque when doubled up, so we are going to do that in a few places.

The 70% aluminet also arrived. It cuts down the heat a lot, but I think you'd still have to wear sunscreen underneath it.

gyre · Post by **gyre** » Sat Jun 20, 2009 1:07 am

http://www.tenax.net/agriculture/products/aluminet.htm
http://www.tenax.net/agriculture/reflecting_screens.htm
http://www.tenax.net/agriculture/index.htm
http://www.tenax.net/worldwide.htm

pyralspite · Post by **pyralspite** » Sat Jun 20, 2009 4:48 pm

[quote="phil"]Remember though that if you double 60% shade cloth you get 120% shade and you'll end up with ice in your tent.[/quote]

Is that the same branch of physics that dictates when you plug in a microwave oven backwards, it freezes whatever you place inside? :)

Token · Post by **Token** » Sat Jun 20, 2009 5:26 pm

For a lean-to shade I would recommnd aluminet over regular shade cloth. It is lighter and transmitts less radiant heat. Worth the extra $$. Tarps are not good for this due to the sail effect that will wreck your cars finish.

If you park your car the right way you can be in full shade from the morning sun provided your small tent is right next to it on the west side.

You can use shadecloth or aluminet under tension to make it wind resistant. Both are very strong and resist tearing.

swampdog · Post by **swampdog** » Sat Jun 20, 2009 5:52 pm

Here's some info on the shade structure I was talking about.

My first year campmates found this design for a quonset type shade structure and built it for pretty cheap, using 80% shade cloth as a covering. It was shady and breezy, easy to put up, cheap to build. The only drawback is that it's long and (relatively) narrow, so it was kind of like a tunnel, but it seemed fine to me. My campmates put their fairly large tent under it, we had a cooking area, room to sit, and even room for our bikes much of the time (5 person camp)

This structure was 30' long, with a 20x30 piece of shade cloth as a covering. With the shade cloth going down to the ground, there was zero problem with wind knocking it around.

Besides the shade cloth, maybe $40 of pvc, $20 rebar, and a few bucks for incidentals.

http://www.maxicon.com/Burning_Man/PVC_ ... _playa.htm

Here's a picture of ours that year - it wasn't really taken for documentation purposes, so it doesn't "show it off"

http://tinyurl.com/5a7rz

Bob · Post by **Bob** » Sat Jun 20, 2009 8:51 pm

Stop complaining and put on a sweater.