Shade Sail Poles

Following the removal of the shoddy pagola area kindly left by the previous owner we now plan to install shade sails, similar to those commonly seen over sandpits at schools etc.

Does anybody know what size gal poles I should be installing. I would think that the wind loads would be on the high side .... I was think along the line of 100-150mm diameter.

Is there any trick to know about positioning the sails for best effects?

Before posting I have done a quick Google search and come up with this ......

"Shade Structure: For each sail two galvanised posts (125mm diameter) were sunk 1200mm deep into the ground and secured with rapid set concrete. A professional tension device was used to tension the sails, however turnbuckles, d-shackles and chains will suffice in a residential space."


Thanks

Sir Stinkalot

Quote:

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Originally posted by Sir Stinkalot

Is there any trick to know about positioning the sails for best effects?

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I think its best if they are off the ground. :D
Hope this helps.
Cheers, Allan

I have just measured the shade sail posts at work and they are 100mm X 100mm square posts with caps. Fittings are stainless and look like the standard boating eye hooks, shakles, turnbuckles and rope.
One post is 2.4m off the ground and is angled away from the sail and the other post is 4.6m, vertical and has a wire stay fixed back to a brick wall. When the posts were installed I did notice the hole was deep but I don't know the depth.
Bunnings sell the sails (5m X 5m x 5m) under Colorado (I think) branding so you may be able to get some info off the box.

I put up a shade sail using some 76x38x1.6 galv patio tubing. Had it powdercoated and it works a treat. The posts are 3.3m long, sunk 800mm into a 300x300x900 concrete footing. Gives me 2.5m clearance under the sail. They've been put in so that their 76mm axis is in line with the load.

The posts do spring a bit under tension but ithey're as strong as!! They're not going anywhere and I've been able to put on enough tension to get the sail looking nice and taught and totally eliminate any kind of flapping. Moves a bit, but not much.

I do think that 100mm posts are more than is needed for a domestic shade sail. I can appreciate the need for larger posts in a commercial scene where the sails are usually pretty big, but for the average 5mx5mx5m triangular sail or 3.6m square sail, the patio tubing is just the trick. Anything else, in my view, is over-specifying.....and expensive

Cheers



By the way, the Bunnings shade sails are Coolaroo brand. That's what I've got.

Forces on shade sails can be mysterious iindeed, and quite large, by way of example, my neighbour has had an 8mm eye bolt straightened in a squall, replaced it with a 12mm one, so far so good!.

Not too many structural engineers are comfortable designing them and as a result many seem to be over-engineered.
Basic principals are:

1) if it breaks it probably wasn't strong enough.

2) if it doesn't break, you probably could have saved some money and built it a bit lighter.

Cheers,

P




:( :o :( :D

Sails should be angled for good looks - a dead horizontal sail does not look good.
Poles should be slanted slightly back from the sail for strength.

Tracer wires can be used to move poles further out or too allow attachment to walls that are further away from the corner of sails.

Note that it is more than the diameter of the pole that determines its strength - there are also different wall thicknesses.

Sir Stinky...

I have installed a couple Shade Sails in the past and can give you a couple of hints:

Pole size should be approx 100mm dia (galv post) with a 5-6mm wall thickness - I picked mine up from a scrap steel yard and only had to pay by the Kg.

You will need to sink it in at least 900mm (1000mm better) and fill it right up with concrete - when you set the posts in, lean them over on a slight angle, AWAY from the centre of the sail (if you set them straight, the tension that pulls them in will make them look crooked - but if you lay them over a little, they look like they are meant to be that way and they hold the tension better) make any sense?

Go for a sail with a stainless steel wire around the outside (proper custom made) - they can be tensioned almost trampoline tight - the off the shelf ones flap like crazy, and cant be tensioned much at all.

Custom made sails are well priced if you do all the work installing etc. (most will probably do a good price if you pay Charlie ASH;) )

I think I used 10mm Stainless fittings ?? whatever they are - they handle the Summer thunderstorms OK.

Dont fit turnbuckles to all corners - use one turnbuckle as security and use that 4-5mm "silver" rope (wind it through both the sail ring and your fixing point - several times) it acts like a tensioner, then tie it off. Turnbuckles will "Jar" and be quite noisy when the wind moves the sail up and down.

Aluminium sail track is nice to use if you want a flush finish against your house - cheap as chips from an aluminium supplier - you only need to specify what side you want to fit into the track, and your sailmaker will do his thing- and the big advantage is it spreads the load across the entire length (instead of just two points)

If you are fitting to your facia on you house - go absolutley crazy re-inforcing the back of it!!! you cannot have too much back there!! You need to have whatever fitting there - tied back so the tension is pulling on the roof joist/rafter, and not on the facia.



I hope some of this helps - Both sails I have done (one about 5m x 8m with sailtrack - one about 4m x 7m with high point up through a roof tile) are still shading nicely 6 years on.

Best of luck...

Dohboy....

G'day Stinky - There is a new sail maker recently moved in to the factory a couple of doors up from us at 71 Little Fyans St Sth Geelong. I reckon it would be worth paying them a visit for info.

Cheers - Neil :D

Ok,

I have managed to buy some posts on the cheap. I investigated 100mm gal poles with a wall thickness of around 3mm, I needed 4 posts at 4m meters each ..... the price was $25.00 p/m.

Not happy with this I went to the local demolition yard and picked up some old fire pipe for $5.00 p/m. The pipe is 110mm diameter with a wall thickness of 4mm.

As you can see from the photos it needs to be cleaned up. I plan on using the angle grinder and wire brush to remove the surface rust and then paint on a rust repellent and then a few coats of exterior house paint. I will need to fill the small holes with automotive bog.

Does anybody have any recommendation for the rust repellent undercoat? Also is there anything I can do about the rust on the interior of the pipe? I plan on capping the top so water can’t enter, or will it take so long to weaken the 4mm thickness that I shouldn't worry about treating the interior walls?

Thanks

Stinky.

Stinky, don't use the rapidset concrete, it's not actually structural.

Mick

Mick,

The bloody holes are so deep that I will need to mix up my own concrete the old fashioned way :)

Stinky,
Don't forget to weld a couple of cleats on the bottom of the post to give it more bearing area in the concrete.

Mick

Paint:

Have a talk to a galvanising company. The cost of getting stuff hot-dipped is often not much more than the cost of buying the paint, and the blokes that do galvanising will sand blast and "pickle" the posts first as well.

After galvanising, you can choose whether to paint or not.

Rusting from the inside:

Drawing a long bow here, but the weakest spot from observation is the line at ground, right where the concrete shrinks away microscopically, just enough to hold water most of the time. Recent experience says 4mm will be rusted through in 15 years in a coastal environment if not maintained. At least you can see it happening and shouldn't get a surprise!

A bit of epoxy tar on the below ground part should fix that for your lifetime at least.

Concrete

Take Mick's advice regarding cleats on the bottom, and make the footings twice as deep as you think you'll need. Last one I was involved in was not large, and engineer specified footings 1200 deep by 600 diameter, belled at the bottom.

It's the uplift you see ..........
or so I'm told!

Cheers,

P

Stinky,
to help prevent rust at ground level like P warns about, be sure to have your footings slightly above finished ground level and the concrete high around the post and falling towards the edges.

Mick

Stinky,

I'd look at getting a quote from a powder-coater. Could galvanise first too, I suppose.

What's your budget again??

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Originally posted by q9


What's your budget again??

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Budget???? whats that again. The garden budget went out the window yonks ago :)

The footings for the posts are going to be 400diamx1200mm. I plan to weld on some pokie outie bits on the bottom to allow for better connections to the concrete.

After the problems associated with getting them home I will not be taking them off site to be treated. The rust on the surface isn't that bad so I will give them a quick wire brush, wack some kill rust stuff on and then a top coat. I don't plan on being in the house in 15 years time so if they fall over then that will be fine with me.

Good advise about the tapering of the concrete away from the post .... this is something I will need to look out for.

Stinky.

Oh well, if you really MUST do the hard yakka yourself.:D......

Try rust converter first. I did have the workings explained to me, but it turns the red stuff into a more or less inert black stuff and seems to work well enough.

Get a wire brush for your 4" angle grinder and get rid of all the loose bits first. (Wire brush works best if you don't have a shirt or shoes on, but you must have your eyes closed at all times :D :D :D -only joking kiddies ) Don't worry about the inside though!

My boat trailer similarly treated then top-coated with good old industrial strength hammertone has lasted in the weather for four years with no sign of deterioration.

Cheers

P

stinky check out wattyl super etch as an undercoat.

Years ago telecom used to coal tar epoxy any thing that went below ground.
cheers

Budget? what's a budget? Anyone that's had any dealings with architects knows that they are sensitive "artistes" whose grand creative vision must be untramelled by plebian, narrow minded concerns over mere money. :D :D (And of course all tradesmen are illiterate, beer swilling yobbos without an aesthetic bone in their bodies, who wouldn't recognise a thing of beauty if it jumped up and bit them on the bum). Sorry Stinky, couldn't resist, don't let me get started about architects and money.

Mick

Mick,

Are your own true colours showing?:

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all tradesmen are illiterate, beer swilling yobbos without an aesthetic bone in their bodies, who wouldn't recognise a thing of beauty if it jumped up and bit them on the bum.

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There was a time when "proper" tradesman couldn't even spell aesthetic. Have you been reading arty farty magazines under the sheets at night? :) :)

At this point, I must confess to sharing your sentiments AND in a former time, Stinky's profession, which in part goes to explain my propensity for priming everything, and why I do other things to actually make a living.

On an architect's salary, it's a wonder Stinky can afford to pay attention!

Don't let the big bad tradie's get to you Stinky, bite off more than you can chew and chew like heck!!!

Cheers,

P

for removing rust & paint there is a new grinder wheel out that looks like a corse toffie covered scotch brite.

I tried one they are great whips the paint & rust off leaving shiny metal.

you will want to grind any nasty flaky stuff & those welds first.

beats a wire brush by a mile if you actualy want clean metal.

not real cheap & you will need a few for that job but worth every penny

cheers

dont worry 1 in 10 architects is a real person.

BitingMidge,
At this point I must confess that in a previous life (at least it seems that long ago) I went to art college and then worked in graphic arts before realising Ididn't want to work in an office and that I was more practical/mechanical than artistic. Hence not only can I spell "aesthetic", unlike most architects I can tell the difference between it and "cost plus".:D

Mick

BTW, Stinky, I'm dissapointed that the title of this thread isn't shade sail polls .:)

Mick

Hi there... not sure if anyone is still reading this thread, but I have a question.

I plan on installing two 5x5m sails purchased from bunnings at my home.

I will be fixing most of the fxing points to the house facia, using pergola mounting brackets which bolt directly to the roof struts.

I am hoping I can get away with using two posts, rather then three. The post in the middle I have planned to hopefully hold two fixings from a corner or each sail, rather than a seperate post for each corner. Does anyone see a problem with this?

I am interested in hearing your thoughts....

Hmmm,

When I had my patio installed, the company flatly refused to install a shade sail attached to the facia. The engineer recommended that the be installed only to poles, or if need be, to an un-eaved wall with some large 4-bolt plates. Apparently the bunnings versions have a history of ripping facias and patio gutters off after home handyman jobs. Even claimed that a huge shadesails had been known to rip holes in improperly mortared walls. Hmm.

The easterly wind gusts where I am are frightening, I'd leave shadesails to someone who knows what they're doing if you're in a windy area.

The only problem that I have where I want to put them is that I do not need posts as the sail will be going right upto the house. Walls are not high enough to fix to mortar/bricks etc, so was going to get the brackets.

The brackets that I am talking about are the ones that go through a hole cut into the aluminium facia and then bolt directly onto the roof beams inside under the roofing. Not directly to the facia panel itself.

Hi All,
Two vague observations I'd make are:
1. I have Bunnings sails (I think they are Coolroo brand) and they stretch a long way so allow an extra 500mm at least on your original spacing. I didn't and it was going to be difficult to move the house to make the distance bigger to retension the sales, so I built an extension instead. :)
2. I secured my sales to the facia of the house with a huge steel brace inside the roof that secured the eye bolts back to the wall and trusses. While it never moved and was as strong as anything, the costant flapping of the sail vibrates through the house (Steel frame) and was very annoying.

So doing it again, which I intend to with our extensions complete, I am going to use poles to suspend the sail over the deck so that they do not contact the house at all and I will get some custom sails made so they don't stretch and sag which looks terrible. Incidently, with some of the stronger winds we have experienced I have seen the one pole (100mm with 4mm wall) I had in place flex as much as 50mm, thank goodness it was in the ground 1200 and angled back!!

My 2c worth....
Anthony

Hey thats cool, thanks for your 2c worth...... The feeling that I am getting is that there is alot of planning that I need to consider, as you said with the stretch factor of the sails.... the flapping in the wind (allthough we plan to pull down during winter to let the light inside when needed.) etc etc. The problem that we have also is the limited budget......
We had a price on a proper sail installed by a custom sail company, but it was like $5000 for what we wanted.... with the proper facial beam to spread the load accross all the trusses not just a single one etc etc......

Do not know what to do now...

Hi MystikWeb,
Sorry to put a dampner on things. I just remember being really dissapointed with the result. While the sails were up they were really functional and made our deck area a great place to be. It's just the they sagged a bit and the noise they made was a bit annoying. We also took them down for winter so the bulk of storms had no effect.

If you have the sails, allow heaps of 'stretch' space and put them up. At worse you'll loose the roof ;) , at best (more likely!) you'll have a great place to sit and have a beer!

In the roof, get some cheap steel and you can tech screw it across a number of trusses to help the load and also get nice big eye bolts. Another possibility is to put a big rubber ring in between the sail and eye bolt to help soak up the jarring but I'd make sure the sail is well secured around that as well. Please note that I am not an engineer though and while I was happy with my over engineered braces it will be different for your roof!

Just some more thoughts! Like I said, at best you'll have a great place for a beer!

Anthony

Thanks for the comments.

The braces that I am looking at using, require me to cut a hole in the alum facia's. The brackets are like a t-peice with a 45 degree kink in them. which slots in through the cut hole, and allows you to bolt the main stem of the brace directly to the roof truss.

I was also going to get some cheep steel to place on the other side of the bolts, to also dampen the load when bolting to the truss, kinda like a sandwich of metal with the wood truss in the middle. its kinda hard to explain without pictures if you know what I mean.....

So what your also saying is that if we get 5mx5m sails, that would stretch to 5.5x5.5? plus making allowances for foxing points, could really bump em up to 6x6??

Hi All,
I was at the zoo recently and noticed that shade sails used above the orangutang enclosure had ia cool idea whereby the cables were connected to hand operated boat winches mounted to the poles which allowed the sails to be re-positioned according to the summer or winter sun patterns.
Cheers
Todd :)

Hi MystiWeb,
I know it sounds a little extreme but I started out with 3 X 3 triangles and 400mm(approx) gaps. After about 2 months I was running out of adjustment. I would say that you can always take up the slack of a large gap but it is difficult to tension the sail after you have run out!

To start with you could position your sails to the house side (or side that is needed to block the sun) and then as they stretch tension them to be more even.

The brackets sound OK, I guess my test would be will they easily support my weight swinging about because with a full sail of wind the forces would be high. Once again, being the non-engineer that I am, this is the technical process.... :)

Good luck!
Anthony

Stinky,

How big are those holes in the tube, and where will they end up on the finished product?

If possible keep them close to the top of the poles, or embedded well below the top of the concrete footing.

Given your coastal environment I'm in favour of galvanising. Rust stains can look really poxy, even if there is little structural damage.

Ian,

I filled the holes with auto bog ..... they were fairly small ... about 20c size. I then applied a few coats of special primer ..... I cant recall the make as it was done quite some time ago. Then there was about 3 coats of exterior house paint. I then put the poles with the holes into the ground where possible. I used a mini mixer to fill the holes which took less than half an hour. I wouldn't have a clue where the remainer of the holes are now to be honest ... there were only about 7 or 8 in total of the four poles. I still need to cap the top but other than that they are looking fine. We are a fair way from the coast so I am sure that the posts will last 20+ years.

Stinky

Guys,

I've been installating shade sails in Melbourne since 1996.

I am happy to share my professional experience on shade sails, poles, brackets etc.
Just be aware that with the climate changes your shade structure should be very solid - otherwise you are asking for trouble.

To get my details visit:http://www.quick-shade-sails.com

Yours.Brian