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Big roll off roof too heavey?

cgarry

By cgarry
in DIY Observatories

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cgarry

cgarry

Posted
Posted

I am looking into getting an obsy and after much reading of threads on here I have come to the conclusion that bigger is better.

With this in mind I asked for a quote for an 9 foot x 9 foot ROR obsy. However, I was warned that the roof on this would be' extremely heavy', so I am now taking some time to think about this.

What are the general views on this? Do people with obsys of this size have problems? Would the roof be too heavy or just require a pulley system to open it?

Cheers,

Chris

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Helen

Helen

Posted
Posted

My Obs is 11x8 and the roof than the shed people built for me was far too heavy. I did rig up some pulleys, but that was fiddly to use and still meant I was pulling heavy weights when cold and tired in the middle of the night. So after 3 years I bit the bullet and got a new lighter roof built on proper runners. The difference is amazing - one hand operation! I know taking out weight made getting the roof moving easier, but I think investing in a proper rolling mechanism has also made a huge difference to the amount of friction/resistance I have to overcome. I went for gate rollers and track. Details of the roof are here http://stargazerslounge.com/topic/117376-observatory-re-work/page__hl__+helen#entry1162924

Helen

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Gina

Gina

Posted
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Only problem with polycarbonate is it would make your obsy into a greenhouse. Unless you could cover it with black polythene sheet which I guess could be a possibility - or maybe even black plastic paint. If you make a lightweight roof, make sure it's well held down, otherwise a strong wind will suck it off and take it up into the sky. I had that with my wooden roof much to my great surprise and shock! :(

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Gina

Gina

Posted
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My Obs is 11x8 and the roof than the shed people built for me was far too heavy. I did rig up some pulleys, but that was fiddly to use and still meant I was pulling heavy weights when cold and tired in the middle of the night. So after 3 years I bit the bullet and got a new lighter roof built on proper runners. The difference is amazing - one hand operation! I know taking out weight made getting the roof moving easier, but I think investing in a proper rolling mechanism has also made a huge difference to the amount of friction/resistance I have to overcome. I went for gate rollers and track. Details of the roof are here http://stargazerslou...en#entry1162924

Helen

Best option but not cheap. I went for 4" (100mm) hard rubber tyred wheels rolling on 3" x 2" timber, well supported. I can open and close my roof with one hand (just). it's 8ft square and rolls over my 7ft x 6ft warm room.
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pete_l

pete_l

Posted
Posted

The weight of the roof is not an issue (in fact, to stop it blowing away: heavy is good). The crucial factor is the quality of the wheels & bearings on the "roll" part and the smoothness of the track they run in.

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ollypenrice

ollypenrice

Posted
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My biggest one is 2.6 by 2.9 metres which works out about the same area as yours. It also has deep roll off sides attached since we have good clear horizons. I made it from from 2.5cm square section steel tubes (the crossmembers are doubled up and separated by 2.5cm to make girders.) The top is fitted with corrugated steel panels and the sides with ply. It rolls on cheap DIY shop wheels tracking in U section channel and is a piece of cake to open and shut. I'm not very big and use one hand. We get wild mountain weather here when it isn't hot and sunny and it's been as good as gold.

So no, it can easily be done with the right materials.

Olly

ROLLING-3-L.jpg

sides1-L.jpg

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cgarry

cgarry

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Thanks for all the replies, plenty to consider. I think that the roof should be heavy enough so that it does not act like a kite, but I would hope that the weight should not be relied on to hold it in place. I think I am now of the opinion that pulleys should not be required to operate the roof and money invested in the runners and wheels is money well spent.

I am wondering if throwing money at the problem and getting one built for me is the easiest option after all as you don't get to specify these little details.

Cheers,

Chris

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ollypenrice

ollypenrice

Posted
Posted

The fact that the professionals think it will be too heavy does push me towards the self-build route I think. If only I had the time and the skills!

Chris

Couldn't you talk to them about alternave construction methods? They may be stuck in one particular mindset. The steel framed corrugated galvanized roof is easy to make and simply is not too heavy. A fabricator would make one in an afternoon. It took me two days. BTW, any roll off can be made 'captive' very easily so that it can't blow off.

I'm not at all a DIY person but you can learn to do things if you decide to do so.

Olly

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pete_l

pete_l

Posted
Posted

The fact that the professionals think it will be too heavy ...

I'd have a word with them and make some polite enquiries about what they were intending to make the roof from. It sounds a bit like there's a gap in communication - either in their "mind's eye" of what you're asking for or possibly what they consider "heavy" - as if you were planning to lift it off singlehanded.

You'd expect something like this to be either corrugated sheets (pop down to Wickes and give them a heft, they're not too bad) or ply with a bitument/felt top covering. - both with a timber framework to hold it rigid. Even if the roof weighed in at 300 lbs, that's still roll-off-able with suitable tracks/wheels.

Maybe print off some piccies of other peoples' RoRs as it's very unlikely your builders have ever seen one before.

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Carbon

Carbon

Posted
Posted

The weight of the roof is not an issue (in fact, to stop it blowing away: heavy is good). The crucial factor is the quality of the wheels & bearings on the "roll" part and the smoothness of the track they run in.

I agree. I used four 4" v-grooved steel casters riding on 16' long inverted angle iron rails and my very heavy 8'x10' fiberglass shingled roof rolls out smoothly without much effort.

post-23888-0-97624600-1350493112_thumb.j

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nytecam

nytecam

Posted
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This is a common DIY problem eg building a RoR bit by bit then on completion realising how heavy and cumbersome it is to roll aside :eek: The clue is to make the roof strong, lightweight and well anchored to ensure it can't lift in high wind :cool:

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laser_jock99

laser_jock99

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I have a 10' x 10' roll off roof which I estimate is around 100kg. However it glides on 14 rubber wheels so most of the time is a breeze to move (except when the rubber weather flap decides to get trapped under the runners....). So the weight is not the problem- its how well distributed the weight is and how smooth your rollers are that counts.

Dscf4369.jpg

Dscf6262.jpg

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malc-c

malc-c

Posted
Posted

As others have commented, it's not the weight of the roof that's a problem, it's how free the rolling method is. Once you get the thing moving it's not a problem. My roof is approx 8' x 9' and can be moved single handed.

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Freff

Freff

Posted
Posted

As others have commented, it's not the weight of the roof that's a problem, it's how free the rolling method is. Once you get the thing moving it's not a problem. My roof is approx 8' x 9' and can be moved single handed.

Agreed... my roof is 16'x9' and about 700lbs. It's double skinned with 9mm OSB sheet and 0.7mm profiled steel sheet. It sits on 16 x hard poly wheels and once moving can be push one handed.

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Gina

Gina

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I think I'll have to measure the force required to open my ROR sometime. I know I can open and close it with one hand but I don't actually know how strong I am :D Anyway, I'm looking forward to the reversible motor winch coming in the next day or two :)

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