Roll Off Roof Observatory

[JTEC]

The Society I belong to wishes to rehouse its permanently mounted scope - a 20” fork-mounted Newtonian - in a well constructed roll-off roof observatory 4m x 4m square.  Can anyone recommend a good UK supplier/builder of this sort of observatory please?  

[malc-c]

I think you'll struggle to find a company that specializes in custom observatories that can meet your specification.  Have a read through the DIY Observatories here as there is lots of information on how people built their own, or companies used to build and supply traditional shed designs with roll off roofs.  Mind you 4m x 4m will require some engineering to be able to span that width and roll.   If you come across a company called Home Observatories UK DONT place an order.  There is a long thread where members have gone as far as court action to get back their deposits following failed orders.

The alternative would be to contact Pulsar who produce Dome observatories - I'm sure they must have used reputable builders to work with when siting a dome on a large structure.   Or contact a local builder who could draw up plans and quote for its construction.  You will need planning permission for a building that size, especially if the site is a third party (I had to get planning permission when our society wanted to build their observatory on land owned by an open farm in Letchworth.)

Good luck and I would suggest documenting your project in the DIY section so that the next person asking a similar question can learn from your experience, plus it will make for an interesting read

 

[Grifflin]

Worth having a look at https://outsideology.com/  .  Not cheap but I'm pretty sure they will build to whatever spec you are needing.  Also have good after sales support for snagging etc.

Neil

[JTEC]

Many thanks both!  Yes, it is quite big with consequences for roof design, manageability, etc.  Depending on outcomes, I’ll be sure to report anything of general interest.  Thanks again 👍🏻

[malc-c]

Can't believe that it was around 30 years ago ! - Here is a little background on the Letchworth & District observatory, which currently houses a 14" LX200.   I was recovering from a fractured wrist and had my arm in a cast at the time, but still managed to lay the foundations single handed, not only due to the cast, but no one else could get the morning off.   We met up every weekend to build frames in a barn and transport them up to the site at a top of a field (I'm the guy in the hi-vis jacket).  I was also the main administrator for the project, dealing with planning permission, leases, rent, etc.  There is more to setting up a society observatory than just the construction, that was the easy part.  The main issue is the appointment of an Observatory manager who will be responsible for training any members how to use the scope and that all the Heath and Safety procedures are followed.  Our manager handles all booking requests, and work parties to maintain the building and surrounding site. 

The site we chose was on land owned by the local council and forms part of a working open farm, so we had use of their car park which was ideal for public star parties as we could also use the on site cafe.  However at the time we were based in Stevenage and our society name reflected this, so one of the criteria for this project to move forward was that the society needed to be based in Letchworth and our name changed to reflect the move.  Even though the two towns are less than 10 mile apart we lost a few members, but then gained some new ones.

In addition to planning permission and designing the observatory to meet acceptance form all parties (the farm manager, the council / corporation, and our committee) you need to look at insurance.  Not only for the obvious things like theft of / damage to the scope or equipment, but public liability insurance to cover any accidents or injuries.  It maybe worth contacting the Federation of Astronomical Societies and make your club / society an affiliated member as I'm sure they offer public liability insurance at a reduce rate due to so many societies signing up (I'm no longer an active committee member these days so things may have changed ).

Hope that helps

[JTEC]

Many thanks, Malc. That’s very useful and interesting.  The scope has been housed in a dome for maybe 30 years, but the structure is beyond repair and needs to be replaced.  Disuse during lockdown didn’t help. A new dome is not affordable, so for that and other reasons, we’ve been looking at run-off options. We have a smaller run-off on the site that accommodates an imaging facility, based around a small refractor, and that we built ourselves.  A 4m square roof, though, is a different proposition, structurally and in terms of mass, etc.  The walls are not hard to source from good local shed suppliers but nobody wants to do a rolling roof. We’ve looked at buying the walls and building the roof ourselves and have considered various materials for it: wood, aluminium, plastic, etc.  Ideally - to save time and working around exposure of the instrument, electrics, etc, during a drawn out build (which, given the kinds of availability issues you mention, it would be!) we’d like to have it all done and dusted for us by a single provider.  We’re looking at a few.  Outsideology, who, judging from testimonials, seem to provide a decent product, quoted us ‘about 30K’, which is way beyond our resources.  We’re waiting for other quotes and will then have to see what approach is most practical and affordable for us.  Thanks again - anything interesting I’ll share. 👍🏻

John

[Carbon Brush]

A company based in Worksop have featured in a couple of SGL threads.
From what I recall they are flexible about designs, features, etc.

http://www.shedshedsheds.co.uk/portfolio-item/home-observatory/

[malc-c]

The biggest expense will be time, especially if you contract a builder to do the job.  I know cost have changed since a decade ago, but I built my 2.2m x 4.8m ROR observatory for under £2,500 and that included the hiring of a mixer and the purchase of a chop saw, with the quality T&G cladding costing £400.  My build thread is in my signature, and covers the construction of a 4 course dwarf wall, suspended joists and traditional studwork for the walls and roof.  Even making a 2.5m x 2.2m roof from studwork and 18mm OSB the roof is heavy to move.  A 4.m roof made in the same way would need some form of power assistance to move.  I dare say that the use of aluminium would lighten the roof, but then the cost will be higher.

Personally I wouldn't look at using sheds.  There are very few sheds that will be strong enough to support the roof, and saving a few bob now might lead to a costly expense in a few years when parts need replacing.  Companies that offer wooden workshops or garden houses may be more accommodating to constructing something more sturdy.  Again, your circumstances may be different but as we needed planning permission we had to submit building plans at the time.  Now these don't need to be full blown architectural drawings.  So long as they are clear and have the various elevations and material specifications you can draw them up yourself.

Now again I can't compare costs of when we built our observatory in Letchworth, but our estimated costs was around £3000 in 1993, and we secure a grant for 50% of the budget provided we raised the other half.  With some rejigging of finances our treasurer soon had the bank statements demonstrating that we had met that condition and the grant was deposited shortly after.  Using an inflation calculator that £3000 equates to around £7,800.

Good luck with your research, and please keep us posted.  Detailing the steps you go through may well be helpful for the next person / society wishing to do the same.

[JTEC]

Thank you very much for the information and insights Malc and C Brush.  Our investigations and discussions are still ‘ongoing’ - I’ll post again when we have something useful to pass on.

ATB

John