Need shade structure tarp canopy advice

[permeant]

Hi all,
I've tried long enough to find a thread discussing this, and there must be one, so if you know of it please redirect me.
I'm designing a tarp canopy for our camp, a la creativeshelters.com.
I'm shooting for a 30ft wide by 100ft long rectangle, flat roofed. My dream is to have as few internal upright supports as possible. I envisioned creating five adjacent 20ftx30ft spaces using five 20x30 tarps and 1 inch EMT throughout (using 10 upright 7 foot lengths, each 10 feet apart.
People are telling me this can't be done without connecting the tarp-supporting EMT tubes with an interior grid of EMT, which would need to be supported by interior uprights (therefore making each 20x30 supported instead by 12 uprights).
If this description is too hard to understand I'll throw in a SketchUp diagram.
Has anyone done this before with large tarps of this size? Can it be done by increasing the diameter/strength of tubing to 1 3/8" pipe? Of course the whole thing will be guyed down with ratchet straps.
Thoughts? Thanks!
adam

[Packoderm]

http://www.canopymart.com/_e/LARGE_COMM ... Canopy.htm

[motskyroonmatick]

Welcome to ePlaya!

I made my own 20x40 flat shade structures. Mine are of the flat grid supported by uprights in nature. It would be a very big challenge to make a flat shade shelter without the flat grid. I use 1" square tubing for all uprights and grid pieces. I made Tee, X and Ell socket connectors out of slightly larger tubing. I think 13 feet is the largest span that is workable with this material. My length spans are 13 feet apart and my width spans are 10 feet apart. I still have to run a X of twine in each square to hold up the shade cloth. It works well. Uprights at the corner of every 10 x 13 square doesn't present much of a navigational challenge and the furniture used under the shade usually ends up placed in such a way that there are very few independent uprights exposed to foot traffic. It seems to evolve that way naturally. Zip ties work very well to secure tho outer edge of the shade cloth to the framework. I use tennis balls on the bottom of all uprights so that they don't sink in to the playa. This prevents allot of maintenance of guy lines. Every upright on the edges gets a guy line to a rebar stake.

I recommend knit shade cloth of at least 80% shade with double reinforced edges, grommets every 2 feet and double grommets on the corners. Tarps are louder than shade cloth in windy conditions. For me the noise factor and less wind resistance make me only use shade cloth. Knit shade cloth does not unravel much when it gets a hole in it where woven shade cloth will come apart much easier and MOOP much more.

This is a huge shade you are talking about but a doable project especially if you use commercially made connectors.

I also recommend using a galvanized metal product such as EMT. My mild steel structures have lots of corrosion after 3 years of use on the playa. All future shade structures I make will go to the galvanizers for a nice coating of zinc.

[EspressoDude]

If you are planning on shade cloth, order ASAP. Commercial plant growers/greenhouses buy up most of the production that is available this time of year.........

[Trishntek]

I would not have much confidence in 1" EMT for such a span. With the 45 degree bracing in the picture and 1 3/8" top rail I'm okay with 20' spans sans center support. Maybe with 6' long bracing it would hold,,,, but I would still put two or four poles down the center,,,, or at least be prepared to place them if necessary.

[Mrpatatomoto]

I may be wrong, but could you extend the 7 foot tall main poles to 10-14 foot but keep the tarps at 7 foot and run ropes from the tops of the poles to different points in the tarp to use as support for the center tarp area? kind of like a suspension bridge.

[peachandpapa]

We have a 20x30 shade structure with a canvas tarp. It has 102 degree gable, with 5 legs per side 7'6" apart. There are no interior uprights to support the tarp. Has worked great for us the past four Burns. Very sturdy, especially with the heavy canvas. We also use 6 guylines and footpads on all the legs.

If you don't gable it, plan on using interior supports.

[phil]

> supported by uprights in nature.

Are there uprights in nature on the playa?

[phil]

> I'm designing a tarp canopy for our camp, a la creativeshelters.com.
> I'm shooting for a 30ft wide by 100ft long rectangle, flat roofed.

I hasn't rained in eons on the playa. Louise and I stopped using flat-roofed tarps when it rained rather heavily while we were out somewhere. We came back to our camp and found the water pooled in the middle of the tarp, our EMT bent from the weight, etc. It didn't burst the tarp, thank goodness, but it was a mess when we stood under the water and pushed up to drain it - lots of splashing all around onto our stuff under the tarp, on close neighbors, etc.

I believe our switching to a gabled roof has kept it from raining ever since. I'm confident, nevertheless, that if you put up a flat-roofed tarp 30x100 feet, you will cause it to rain heavily once again.

[FIGJAM]

It rained last year.

[Dr. Pyro]

FIGJAM, I was about to say! On Monday it rained like hell. Also rained Saturday before the event. Seems to me it rained in '08 as well. We go in expecting it to rain. In 2000, it rained every damn day. In 2002 it came down in buckets one day. So it seems to me, maybe all it ever does there is rain.

[Trishntek]

We have a 20x30 shade structure with a canvas tarp. It has 102 degree gable, with 5 legs per side 7'6" apart. There are no interior uprights to support the tarp. Has worked great for us the past four Burns. Very sturdy, especially with the heavy canvas. We also use 6 guylines and footpads on all the legs.

If you don't gable it, plan on using interior supports.

IIRC your pipe is up around the 1 5/8" diameter. You couldn't do that with 1' emt.

[unjonharley]

/

By the end of the week my tarps are hammered each year..

Took some tarp from a year before and the wind ate it by mid week..
To keep the tarps from failing I just replace them each year..

This year to cut down on the windwhip I'm redesigning.

Insread of coming over the top of the van with a tarp..
This year there will be a car top to attach to. The van is 14 feet so will go with that and 9 foot out.. I will cut a large square out of the center.
Finish the raw edga and put in grommets.. Then cut another square patch, larger than the hole and match grommet holes.. Attach the two tarps with knoted rope.
With enough slack to allow the patch tarp to lift and release the wind..

[peachandpapa]

peachandpapa wrote:
We have a 20x30 shade structure with a canvas tarp. It has 102 degree gable, with 5 legs per side 7'6" apart. There are no interior uprights to support the tarp. Has worked great for us the past four Burns. Very sturdy, especially with the heavy canvas. We also use 6 guylines and footpads on all the legs.

If you don't gable it, plan on using interior supports.

Trishntek wrote:
IIRC your pipe is up around the 1 5/8" diameter. You couldn't do that with 1' emt.

Peachandpapa response:
We use 1" EMT. Maybe my description of "no interior uprights" is confusing. We do have rafters, but no supports from the ground up to the beam to support the tarp.

[permeant]

peachandpapa (and everyone),
Thanks - this is really helpful. But I'm curious how you came to do 5 side supports at 7'6" apart rather than, say, 4 supports at 10ft apart. You have previous experience with the latter failing?
Is the canvas tarp you're using more like shade cloth (wind-permeable) or more like plastic tarp? This variable affects things quite a bit I imagine.
Our current plan is to do 3 20x30 flat-roofed plastic-tarp sections WITH internal uprights where the tents will be, and a gabled 102 20x30 shade-cloth like you've done for the front hang-out area.
adam