Roll off roof observatory help!

I came across 'Building a Roll-Off Roof Observatory: A Complete Guide for Design and Construction' by John Hicks (ISBN-13: 978-0387766034) the other day.

It would be worth getting out of the library, but possibly not worth the £25 that it's going for on Amazon at the moment. It's US centric and isn't as detailed as you would expect from the books title. That said it does give you plenty to think about. Especially when compared to the sky shed plans; e.g. what are the pros and cons of a poured concrete base.

One question though for the people who have built observatories. What, roughly, was the raw materials cost? I know some of you have concrete bases, different roof styles etc. I'm just looking for an idea of how much the wood for the project would cost in a builders suppliers to put a budget for this together.

Hi,

Yes, John Hicks book gives some good ideas, but his plans are for a larger than average size.

Albert, the cost would depend on the size. Mine is 10'x8' (about 3 x 2.4 m) and my budget is about a couple of thousand euro.
I used Sonotube concrete fondations for the building itself. You will also need to factor in tools including electric saws.
The telescope pier will be extra.

John

Al keep in mind that what follows was in 2006.

I cant remember exactly how I can up with the figure but my memory is that it cost me €1200

Timber cost ~€600 about another €400 for the other bits and pieces and I guess the other €200 was cement. The cost of the timber could be brought down by using ply instead of solid planks for cladding. However subsequently I spent 250 on the new roller mechanism which was worth every penny. I guess over time I've added bits and bobs, i.e. security cameras etc but thats something that happens over time. The big shock is the upfront cost of the timber and ancilliaries.

Hi James,
I was wondering how you were getting on with your plans. I am in the planning stage myself. I was looking for a suitable garden shed to convert and I think I found one. I think a flat roof would be easier to roll off. have a look at my site www.imageorion.com/observatory Any comments and ideas for improvements would be useful and welcome.

John

Hi

I am late to this subject as only recently found the web site when trying to get information about roll off roof type and telescope dolly. Like you I aim to observe in the far NW Donegal. As you say the storm issue is very real.
I have built a 1.5 story hut of twin skin breeze block which I can finish with a pier up to the second floor built upon a 600mm diameter x300mm high pier base on top of a re-enforced floor as the structure was build on bog excavated down to rock. This would allow me great standing shelter with walls at 1.85m with a roll of roof opening. I appreciate the need to manage any potential water ingress but my main concern is being absolutely sure that when closed it would not lift off in the frequent severe storms. Even inside my house you are worried when the gusts gust. I reckon a series of toggle bolts or turn buckle type bolts would manage this problem. The roll off would be over steel tracks screwed or welded down onto 8cm box steel section running horizontally on the walls and being supported when rolled off by the box steel supported by steel verticals. As the horizontal box steel sits at around 3.5-4m off the ground I needed a maintenance free option. Wood might not be that durable and as the cost of tracks, rollers and box steel would come in around 1000euro I am stuck with considering a telescope dolly which might with import tax, carriage and cost one in at around 800euro but with a fixed roof there is less fear about losing a mobile roof even with toggle bolted.
What did you finally settle on?
Even though the hut is build and has two floors you could always find some othe use for the second floor area.

Regards

Seamas