Propping Up Large Aluminet Span

[SourPatch]

Our camp is planning on providing a 20' by 25' shaded area. We have 70% Aluminet.

The aluminet will be tied to a metal structure on one side and by cars on the other, using the short sides. We will pad the cars very well to avoid rubbing off the paint.

Our original idea was to prop the aluminet with a 10' EMT conduit pole right in the middle (10' - 12.5' mark) but upon seeing how big the material is, we are wondering if we would need 2 poles on both sides at the 12.5' mark in order to keep the sides from sagging too low.

Thoughts?

[some seeing eye]

If you put it under tension from each of the 4 corners, the sag will not be a problem. A home despot 2x4 or 2x3 piece of lumber is tougher than EMT. Bring extra rope and make an x of rope corner to corner under the Aluminet if you like.

[DoctorIknow]

I've used lightweight 12' redwood 2x2's (Lowes/Home Depot) with a plastic bowl screwed on top for years to hold up camo, snow camo, and aluminet that spans distances where sag happens NO MATTER HOW TIGHT it is stretched.

Keep them pushing against the shade material tight, as they can fall. I've never made a "security line" in case they fall, but if you maintain them, they won't fall.

[SourPatch]

If you put it under tension from each of the 4 corners, the sag will not be a problem. A home despot 2x4 or 2x3 piece of lumber is tougher than EMT. Bring extra rope and make an x of rope corner to corner under the Aluminet if you like.

The X is a great idea. I'll try that. As for lumber being tougher, I didn't think we needed much strength given that the only force being applied to the EMT would be downward force by the aluminet.

I've used lightweight 12' redwood 2x2's (Lowes/Home Depot) with a plastic bowl screwed on top for years to hold up camo, snow camo, and aluminet that spans distances where sag happens NO MATTER HOW TIGHT it is stretched.

Keep them pushing against the shade material tight, as they can fall. I've never made a "security line" in case they fall, but if you maintain them, they won't fall.

Yes, we will have a plastic jug on top of the EMT and the EMT will be secured to the floor via an umbrella holder that will be staked to the floor.

[FIGJAM]

You could just pound in a piece of rebar and slip the EMT over that.

[Karma]

Sourpatch,
Weve been using a 20x30 piece of Aluminet for 4 years now. The same piece, the stuff holds up great. A couple things, It will definitely sag in the middle so the above posters suggestion is a good one to put an X of rope corner to corner. 2nd, don't presume that because it doesn't trap air like a tarp that it wont get yanked around in a strong wind out there. We've had it put enough pressure on the post lines to pull up a 2' rebar stake. Bottom line, secure it like you would a tarp and just presume that the Playa is capable of creating a wind strong enough to pull it away. Better safe then sorry ^_^

Also note in this pic we haven't put the x ropes in for sag and theres no breeze right then. In a breeze it will sag more

[Papa_Legba]

for those who have aluminet / shade structure knowledge, let me know where this plan is faulty

a friend just offered to loan his 12x7 aluminet 70% with grommets, which i'd like to use for a porch / shade in front of my yurt. given the lack of prep time (and my remaining funds), i'd like to keep it cheap and simple (construction & set up).

i'm thinking of using 4 pieces of 2x2 redwood, 7' long. which will be ziptied to 3ft rebar stakes (~half exposed above ground), with upside down bowls on top, and separated 7 ft apart in both directions... then draping the aluminet over these, with ~2.5 ft over hang at the long ends which will be guyed down to the ground (using all grommets along those sides to spread out the load).... and running rope in x's between the 2x2's to prevent sagging.

with this, the 2x2's wont bear any of the support for the aluminet. they'll just prop it up. I've used this simple design before with camo netting, but i'm an aluminet noob and it looks like it will catch a lot more wind.

what are the weaknesses in this idea?

[DoctorIknow]

Just this afternoon I am fashioning 2x2 redwood to be zip tied to straight rebar.

I've done this a lot with light things such as aluminet, and no worries, the aluminet doesn't act so much like a sail: it will billow out of course, but, especially if you clamp the aluimnet onto the rope, you can release the clamps if things ever get hairy...

Of course, you do want to guy down the 2x2's in both needed directions, 90 degrees to the stress. If one edge of the aluminet can be secured to the yurt, then you'd only need 4 guy lines at the opposite end of the aluminet.

Why 7' 2x2's? Doesn't it come in 8', and the extra height is very good as when it billows down, there is headroom, at least more than if it was 7'.

I take a 10' 2x2 and nail a plastic bowl on the end to prop up the center. The 2x2 can fall down in windy conditions, so has to be watched. I've never secured the prop up 2x2, although it wouldn't be hard to do with some clamps around the edge of the bowl.

You have a pretty small surface area on that piece of aluminet....much different than if it was a 10' x 20' piece...

Good luck

PS: I see I just said some of the same a year ago in this thread. Yeah, old man me has consistency !

[Papa_Legba]

i appreciate your response!

Of course, you do want to guy down the 2x2's in both needed directions, 90 degrees to the stress.

even if the aluminet isn't attached to the 2x2's? i envisioned guying the net down at 3 stakes on each of the long ends that will extend past the 2x2's, and using the 2x2's to just prop it up... i guess i could just attached the net to the poles and have a flat structure, but i thought my plan would provide a little side shade with the overhanging portions

Why 7' 2x2's? Doesn't it come in 8', and the extra height is very good as when it billows down, there is headroom, at least more than if it was 7'.

typo or mental lapse. 8' is the plan

thanks again!

[DoctorIknow]

I've zip tied the 2x2 onto rebar stakes before, and this year decided to use a router and cut out a curved depression 1/2" deep which will stop movement that zip ties by themselves can never stop.

In the pic, the stake (not rebar for this usage) is resting in the groove.

WIN_20150819_070151.JPG