Roll Off Started

[avandonk]

Here are a few pics of the roll off I have been busy building and more to come. The roof will be 50mm thick polystyrene with colourbond on each surface here

http://www.solarspan.com.au/solarspan/home.htm

Bert

[h0ughy]

looking good

[leon]

Great stuff Bert, :thumbsup: hope you got a permit for that thing :lol: :lol:

Leon :thumbsup:

[avandonk]

Rule 303!

Bert

[HCR32]

I admire you craftsmenship Im the type that would just go out and pay someone to build something like that. Only because I could never trust my own extensive building skills (NOT).:lol:

[avandonk]

You misjudge me Peter my mate who is a cabinetmaker+++ and works in my backshed is the person I have been 'helping' to do all this. I am a mere retired scientist. The design was a joint effort.

Bert

[AlexN]

Bert, How are you planning to flash the center of the roof? or are you allowing enough overhang of the upper section so that rain couldnt possibly get in?

[avandonk]

Correct AlexN the worst weather comes from the southwest (from the right side in the drawing) in Melbourne and the west half of the roof will shield the join. It is all under control. I do have further options with custom flashing to control any potential leakage.

Bert

[acropolite]

Looking good Bert, there's a lot of satisfaction in standing back and admiring work you've done with your own hands. Keep the pics coming .:thumbsup:

[Ric]

Well done Bert, a fine looking structure.

How long until first light?

[rmcpb]

Great choice of roofing. That stuff will be a huge help in keeping the obs at ambient.

[avandonk]

Bit more done. The frame rolls easily with one hand. There will be 600mm of eave on the north side to keep the Sun off the wall in summer. Radiant heat is the problem in summer and the Solarspan should minimise this.

Bert

[avandonk]

Getting closer with this mornings effort.

bert

[Matty P]

Looks great Bert, it is coming along nicely. :thumbsup:

I am just about to start construction of my ROR observatory hopefully by next week or so.

Keep us posted. :)

[rogerg]

Nice observatory :thumbsup:

[rmcpb]

If you pack the north wall with batts before lining it then heat buildup from the sun will be MUCH smaller. Actually, it is worth insulating all of the walls and inserting some vents in the corners of the floor and some under your eves to keep moisture at bay while you are on the job.

Looking great :)

[alan meehan]

lovely job bert the roof design is brilliant should work fine ,looks like you could use a bit of a chainsaw job on those trees behind the shed .
well done

[AlexN]

I second the idea of cutting down some trees :D I suppose though, If they dont block anything you wish to look at/photograph, then dont worry about it...

[avandonk]

In between the rain got a bit more done. Both roofs are safely held down in all positions so the wind cant take them away.

Bert

[theodog]

Looking Good Bert.

[avandonk]

Thanks for that theodog. Here are a couple more..

[Ric]

I'm interested in those rollers Bert. What size and type are they?

How do you find them for with ease of movement

[avandonk]

Ric I got them from Bunnings about $12 each. They have roller bearings and are rated at 140kg each. I can move the both roofs at once with one hand with ease.

Bert

[Ian Robinson]

Have you given any thought to securing the roll off roof against storms ?

The weight of the roof alone will not be enough to stop if being blown off.

See attachment , this is what I will do - eventially - if I ever build a roll off roof shed, I've seen southerly busters here take roofs off car ports that were not properly secured, the wind can generate a lot of lift on a standard shaped roof.

wrt The plywood overhangs at the centre end (see picture 2) straddling the rail-trough . plywood is strong in compression but not in axial tension, would be better and stronger if this was reinforced by steel angle.

[avandonk]

Thanks anyway but the reinforcing and locking has not been installed yet.

Bert

[avandonk]

More progress.I have started to put some gear in. That is mick on the right in his workshop in my backyard.

bert

[mrsnipey]

Whoa, that's bigger inside than it looks from the outside.
Plenty of room to move around without having to step over cables and avoid bumping cameras.
Great work.

[avandonk]

Yes inside it is 3.3x2.8m or 11x9 feet. The walls are 1.8m high to the 'rail'. The unit inside has been cut into two bits as it was too high. It is just the right amount of room. It has all worked out rather well.

Now if the clouds would go away for a few nights.

bert

[leon]

Bert, this is looking bloody fantastic, :eyepop: you would have to be happy with that.

I bet you are stoked. ;)

Leon :thumbsup:

[avandonk]

Yes Leon it works like a charm. Here are a few more pictures with the Solarspan installed. It started coming down just after we installed the Solarspan and not one leak. The insulation is great and should stop any radiant heating in summer. Note the 600mm overhang to the north.

Bert

[avandonk]

A few more images. The roof will be great to stop radiant heat from the Sun in summer as it has 50mm of polystyrene sandwiched between two layers of white colourbond steel.

Bert

[mrsnipey]

Bert, Do you need to seal the polystyrene at all?

[avandonk]

Yes I still have to fit side covers and some flashing. I wont bother with the lower ends where the water runs off. These can be folded or bent down.

Bert

[avandonk]

A few more

[leon]

Bert It is great looking Ob, :thumbsup: however I am a little concerned about the weight those extended rails have to carry the roof when it is open. :scared:

Do you intend to put some vertical support under then later, I think they may need it. :whistle:

Leon :thumbsup:

[Matty P]

Looking great Bert! A lovely design and well put together.

When will be first light? or has it already past?

Just look at the cloud cover in your images.

Well done :thumbsup:

[theodog]

I think you will have to do something with the lower ends Bert, I bet those bloody sparrows will love it.

Hey looks like a very professional project.
Any chance of an article and some plans?:D

[avandonk]

The whole concept for the design was based on the properties of the Solarspan and the size of the deck we started with. Solarspan is self supporting for up to five meter spans and 500mm unsupported overhang. It is very strong yet only weighs about 10kg per square meter. Both roof structures are about 300kg in total so each wheel has nearly 40kg load on average. The Solarspan holds the roof frames rigidly so you can push them from either side without flexure. The beams at their extremities easily support my weight 80+kg. So there is no problem there Leon.

The total area of Solarspan is 17 square meters. The 600mm overhang on the north side ensures the north wall is shaded from the sun in summer. This wall will be well insulated. Having the central opening at the highest interior point will give very good ventilation from the open decking below in summer if opened without allowing the suns direct radiation in. This will ensure the interior is at ambient air temperature and no higher at all times so no cool down is needed at sunset. I will monitor this to see if it behaves as expected.

The major enemy of your optics is excessive heat. Radiated heat in summer is the most difficult to minimise passively. Condensation can be controlled with adequate ventilation. Time will tell if I have thought of everything.

The whole structure evolved from the drawing very early in this thread. Standard building practises were used where possible.

The design is a mixture of Micks building and cabinetmaking knowledge and my requirements for an imaging observatory with good thermal properties especially in summer. I also liked the idea of a split roof as this gives more protection against wind interfering with autoguiding and pesky neighbours lights.

Bert

[avandonk]

theodog I dont have detailed drawings and have no intention of doing them. There are no sparrows in Eltham or at least where I am. Feel free to use any ideas. Each situation has its own optimum solution.

Matty P I have not taken one image for two months due to the weather. The next will be a combination of narrow band and full colour taken with the Canon 5DH in the temperature controlled fridge on something dim like the Helix Nebula for MEGA data.

Tomorrow we paint the whole thing white weather permitting. The bits that are not white already that is.

Bert

[theodog]

OK Bert
I'm a builder by trade and have built my own simple roll-off-roof obs so I'm aware of the issues involved in designing and construsting one's own obs.
I'm always interested in others solutions to the obs problem.
Split roof looks good, practical and a great idea.
May it serve you well.
Well done.

[avandonk]

Got some paint on the observatory yesterday. Here are a few pics and an animated gif with a cameo appearance. I made it white to reflect heat.

Animated gif 3.7MB

http://members.optusnet.com.au/~fmlee/obs01.gif


bert

[leon]

Just love it, and the Animated gif, nice going Bert.

leon

[Ric]

Nice animation Bert.

A quick question, do you have a weather seal between the two halfs when they but up together or does the overhang provide enough protection combined with the roof angle.

Cheers

[bmitchell82]

That was my thoughts exactly, im from northern territory, and let me tell you that sometimes no amount of overhang will protect from water getting in, especially when backed by a nice stiff breeze! :D if it was me ide be making something like a weather strip from a door to flap over. Just like heat electrics and optics do not fare well with water! :) so soft and smooth is dear water but so ever harsh!

[avandonk]

You are all correct. Even though nearly all rain in Melbourne comes from the south west it can give nasty surprises.

I intend to put a flat piece of flashing against the bottom roof top edge and seal it with silastic to form dams at the top of the valleys. The upper roof will have flashing that covers its top end and just clears the lower roof. This will ensure the drip line from the upper roof is well down the lower roof.

In image one the lower flashing would cover the visible timber. In image two you can see how well this would all mate.

Water can flow uphill with the wind behind it and get in where you least expect.

Bert

[AlexN]

Your camera setup is CAH-RAY-ZEE!!

I love it!! :D

[avandonk]

After a full summer the hottest the inside got was about 4C below outside temperature. Even on the worst day where it was 47.5 outside it was only 43.2. That was black Saturday.

Normally the inside temperature is well below outside. It is only sustained hot days that the inside temperature is only 4C below.

The natural cooling of having a wooden porous deck and a well insulated roof really works.

The good thing is once the roll off rooves are opened, every thing is at ambient very quickly.

Bert