It's Finally Time To Build My Observatory

[JayTee]

Greetings,

It's finally time to start building my observatory. This observatory incorporates a unique design feature. One that I have yet to find on the internet. Based on my searches, it appears that what I'm doing has not been done before.

This Observatory will be a 10’ x 15’ building. The observatory side will be 10’ by 10’ and the warm room side will be 5’ by 10’. This obsy will be placed on a 16’ x 16’ concrete pad.

The unique feature of this Observatory is using a rollup garage door as the retractable roof for the observatory side, while the warm room side will have a fixed roof. These garage doors are constructed by the manufacturer to be weather resistant which isn't exactly weather-tight but it should be good enough. They are made to withstand hurricane-force winds.

The building itself will have a sloped roof with the north wall being the high wall and the south wall the low wall, The south wall will be 4' tall and the north wall will be 7' tall.
Reference the pictures below.

The sloped roof design is used to accommodate a winter snow load of approximately 24" to 30" of fresh wet snow. The roof pitch is 16.7 degrees or 3.6 / 12. A removable center support beam running from the north wall center down to the South Wall center will be used to provide extra support for the closed garage door when it is under a snow load.

The observing room will have a fixed pier for my iOptron CEM70 mount. Its location is 45” from the West wall and centered on a line drawn from the North to the South wall. The remaining space will be used for my CPC 1100 to be used for visual work and planetary imaging. All the appropriate trigonometry was used to make sure the roof will close without hitting/touching any of my scopes attached to the CEM70.

The build for this obsy has four main parts: Pouring the footing and pedestal for the pier, pouring the concrete pad for the building (not touching the pedestal), building the observatory structure, and finally, installing the garage door roof. Two separate contractors will be used for the concrete pad and the obsy build. The business building the structure will also install the garage door roof.

Please critique the heck out of this design so that I don't build something that doesn't work down the road. Thank you all for your participation and for helping me construct the best observatory I can.

Cheers,

[KathyNS]

Interesting design!

The biggest challenges will involve the orientation of the roll-up door. Since it is designed for vertical installation, and yours will be closer to horizontal than vertical, one thing that comes to mind is drainage. Will water still run off it adequately? Or will tilting it back like that allow water to seep down through joints in the door structure?

You mention snow loading and have a plan to reinforce it with a removable centre beam. While that will cut the span in half, do you know if the door segments will support the snow load at half their span? Obviously you can't ask the manufacturer, since this is an "off-label" use of their gear.

Will the motor be powerful enough? Tilting the door back will mean that the motor is not doing a dead lift as it would in a standard installation. However, it is now fighting friction from the weight of the panels (and snow) on the tracks. That might be enough to actually increase to load on the motor in spite of not having to lift the weight vector. Will you be putting rollers in the tracks to mitigate this load?

I would recommend making the pad an inch smaller than the building's footprint. This will facilitate drainage and will avoid giving rain an opportunity to seep under the walls. Otherwise, you will have to rely on caulking to seal the walls, and caulking always fails eventually.

I wish you good luck with the build. You will likely be doing some original research for it, so I hope you publish your results for the benefit of others contemplating a similar design.

[Ylem]

Very nice! And a warm room also!

A couple of guys at my club have some similar but without the warm room.

Keep us abreast on your progress

[Bigzmey]

That's exciting!

As Kathy pointed out, my concern even here in California would be that the garage door will not provide the same protection as regular roof from a bad weather. Even if it will hold snow would it provide adequate protection from heavy rain, without leaking over your equipment?

[sdbodin]

Sounds interesting, you sure get a lot more snow load than me being a couple hundred miles southwest. I never get more than 6 inches.

I did not isolate the pier footer from the slab, just a cubic yard under the pier, with re-bar and j-bolts. Did a test when finished with videocam and barlows for 12000mm efl maybe equivalent to 1000x on a star, and only a noticeable 'bump' if I jumped up and down forcefully, normal walking is unaffected. And in 15 years, no noticeable effect on my imaging.

Just my 2 cents,
Steve

[Juno16]

JT,

That is awesome!
I can’t help with the observatory design, but I am really excited for you!
Sounds like a dream come true project and I’m really looking forward to seeing your progress reports!
Best of success and have fun!

[pakarinen]

Cool design! I have no experience with home obsies, but I'd take a close look at the weight of the door and load it will put on the structure if you haven't already. JMO.

[Unitron48]

Interesting design! I too would be concerned with the operation and soundness of the "roof off" roof.

Wishing you the best, and looking forward to updates!

Dave

[bobharmony]

JT - good to see you settling in to your new digs. Like some of the others, I am interested to see how that roof works for keeping the rain and melting snow out of the obsy. I am curious about having to support 24-26" of fresh wet snow. Around here if we get that much snow in one shot it will be the dry fluffy kind, it is very rare to get as much as 12" of the wet variety in a single storm.

Maybe investing in a roof rake would be a good idea. Given the low height of the roof it would be pretty easy to just pull the snow off the roof after it lands there. A low-tech solution to the problem can sometimes be used

Bob

[chris_g]

Hi @JayTee

I'll be hoping for follow up reports as this design is exciting to me to say the least! It's something I could do with some help! I don't have to worry about snow where I'm at, but we do get a lot of rain and potential for hurricanes. So, like everyone else, I wonder about the garage door panels keeping rain out when it's acting as a roof.

Best of luck and hoping for lots of follow up reports!

Clear Skies,
Chris

[jrkirkham]

My questions are going to go in a different direction. What will you use the warm room for? From the look of your design I assume you will link in the computer from the warm room and will mainly need a chair and a desk. I assume this will be in your yard, close to your house.

The reason I ask is that my observatory is at my dark site, three miles from my house. My warm room is 8'X12' with two small lofts. I have bunk beds, small tables, storage, chairs, and heater in there. Once I started storing everything I realized that it was barely big enough. Five feet isn't very wide for table, chair, and equipment storage. The low end will be just high enough for storage trays, but you may have to squeeze around the table a lot. The tall end will be almost like a hallway, since it has two doors in it. If your observatory is just a few steps from the house you might not need much extra room out there.

[chris_g]

My questions are going to go in a different direction. What will you use the warm room for? From the look of your design I assume you will link in the computer from the warm room and will mainly need a chair and a desk. I assume this will be in your yard, close to your house.

The reason I ask is that my observatory is at my dark site, three miles from my house. My warm room is 8'X12' with two small lofts. I have bunk beds, small tables, storage, chairs, and heater in there. Once I started storing everything I realized that it was barely big enough. Five feet isn't very wide for table, chair, and equipment storage. The low end will be just high enough for storage trays, but you may have to squeeze around the table a lot. The tall end will be almost like a hallway, since it has two doors in it. If your observatory is just a few steps from the house you might not need much extra room out there.

Thinking about that, I would incorporate the same size walls for the warm room, then build a pitched roof so you can stand up at both sides, gives you more room for storage with shelves and such if you wanted to keep it the same basic size. You'd have figure out the height of the eastern wall so it doesn't mess with any of the mounts views to the south though, so it might not be doable... You could also move the pier mount closer to the northern wall to help compensate for the higher wall to the south but that again would affect your other mount. Perhaps a bigger floor plan with the same design specs, four feet to the east and 7 feet to the west with a 7 foot warm room, depending on how tall you are, you could change the warm room height to 6 feet. That would also help with the southern view...

[chris_g]

I'm curious as to why the building is smaller than the foundation, expanding the size would allow more flexibility in the warm room design.

[SkyHiker]

Will garage doors even roll down when installed on a not steeply sloped roof? Fun idea but I think it will turn out to be a complex solution to a simple problem with unforeseen gotchas. The ripples on a garage door seem perfect for snow to collect and make it collapse or leak. Also, the lower wall is so low that it won't protect against wind. I would just go with a standard solution with like a roll off roof with tall walls or a dome.

[Gordon]

Couple of thoughts.

I have a 'weather resistant' garage door with the seals between the joints. While the seals will keep the moisture out in a vertical position, they do NOT extend beyond the edge of the panels so water would collect in the space between the panels and would most likely seep through over time. Also my garage door faces south so I get most of the direct sun exposure. That door gets REALLY hot with the sun hitting it. I'm not sure if insulation would help much, but it's something to consider.

[sdbodin]

Missed that point, hot in the summer. I also ignored that conventional 'internet' wisdom and insulated mine and added a small A/C. Just enough to keep the inside at nightfall temps and avoid having to cool the scope from 120F to 75F. Plus that seems like too much thermal stress for those expensive optics to go thru every night.

Overly cautious,
Steve

[JayTee]

Interesting design!

The biggest challenges will involve the orientation of the roll-up door. Since it is designed for vertical installation, and yours will be closer to horizontal than vertical, one thing that comes to mind is drainage. Will water still run off it adequately? Or will tilting it back like that allow water to seep down through joints in the door structure? I'm told by the door manufacturer that with the side seals included there should be very little leakage from the tracks. Also, the door is one solid sheet of steel, so no joints mean no leaking.

You mention snow loading and have a plan to reinforce it with a removable centre beam. While that will cut the span in half, do you know if the door segments will support the snow load at half their span? Obviously you can't ask the manufacturer, since this is an "off-label" use of their gear. The door is a 26 gauge corrugated curtain manufactured from full hard galvanized grade 80 steel. If my math is correct this should hold a little under 2000 lbs or roughly 24" of fresh snow. The fresh snow up here is usually pretty dry and fluffy. With the center beam installed theoretically, it should hold double that.

Will the motor be powerful enough? Tilting the door back will mean that the motor is not doing a dead lift as it would in a standard installation. However, it is now fighting friction from the weight of the panels (and snow) on the tracks. That might be enough to actually increase to load on the motor in spite of not having to lift the weight vector. Will you be putting rollers in the tracks to mitigate this load? Initially, it will have just a chain hoist to get a feel for how much force is needed. My thinking is that I'm dealing with less force from gravity than if the door were vertical, so hopefully, it won't be as difficult to move. A motor can easily be added later. Since the door is one continuous sheet of steel there are no rollers involved.

I would recommend making the pad an inch smaller than the building's footprint. This will facilitate drainage and will avoid giving rain an opportunity to seep under the walls. Otherwise, you will have to rely on caulking to seal the walls, and caulking always fails eventually. The building is designed to be affixed to the concrete pad and then caulked to seal it, inside and out. It is easier on the builder if the pad is just slightly larger than the building's dimensions.

I wish you good luck with the build. You will likely be doing some original research for it, so I hope you publish your results for the benefit of others contemplating a similar design.

The builder is quite excited about this project because his company has not customized and configured one of their buildings for this purpose.

[JayTee]

My questions are going to go in a different direction. What will you use the warm room for? From the look of your design I assume you will link in the computer from the warm room and will mainly need a chair and a desk. I assume this will be in your yard, close to your house. All of this is correct. The pad sits about 150' from the main house.

The reason I ask is that my observatory is at my dark site, three miles from my house. My warm room is 8'X12' with two small lofts. I have bunk beds, small tables, storage, chairs, and heater in there. Once I started storing everything I realized that it was barely big enough. Five feet isn't very wide for table, chair, and equipment storage. The low end will be just high enough for storage trays, but you may have to squeeze around the table a lot. The tall end will be almost like a hallway, since it has two doors in it. If your observatory is just a few steps from the house you might not need much extra room out there. Originally, the warm room was only 4' x 10'. I set up a simulation of the space on my garage floor and quickly realized that 4' wide was not enough. 5' is just wide enough for a desk, a chair and a modicum of storage. Every additional foot of building expansion puts the project further and further over budget!

[JayTee]

My questions are going to go in a different direction. What will you use the warm room for? From the look of your design I assume you will link in the computer from the warm room and will mainly need a chair and a desk. I assume this will be in your yard, close to your house.

The reason I ask is that my observatory is at my dark site, three miles from my house. My warm room is 8'X12' with two small lofts. I have bunk beds, small tables, storage, chairs, and heater in there. Once I started storing everything I realized that it was barely big enough. Five feet isn't very wide for table, chair, and equipment storage. The low end will be just high enough for storage trays, but you may have to squeeze around the table a lot. The tall end will be almost like a hallway, since it has two doors in it. If your observatory is just a few steps from the house you might not need much extra room out there.

Thinking about that, I would incorporate the same size walls for the warm room, then build a pitched roof so you can stand up at both sides, gives you more room for storage with shelves and such if you wanted to keep it the same basic size. You'd have figure out the height of the eastern wall so it doesn't mess with any of the mounts views to the south though, so it might not be doable... You could also move the pier mount closer to the northern wall to help compensate for the higher wall to the south but that again would affect your other mount. Perhaps a bigger floor plan with the same design specs, four feet to the east and 7 feet to the west with a 7 foot warm room, depending on how tall you are, you could change the warm room height to 6 feet. That would also help with the southern view... Since the obsy is on my main property there is no need for a great deal of storage and a pitched roof does add additional cost. Also, the location of the pedestal within the obsy room is not cast in stone yet. (pun intended). I'm still experimenting with the floor plan layout in my garage to come up with the ideal location for it.

[JayTee]

Thank you all for commenting. Some very good ideas were provided.

Wrapping up all your great ideas.
I'm assuming that some sort of custom dam will need to be constructed around the rails (without inhibiting the door's motion) to help make the roof a little more weather tight.
The roof will be painted white to fend off some of the daytime heating.
The reason the pad is 16' x 16' (instead of 11' x 16') is that I have always envisioned having small star parties on-site and that extra 5' of space to the south end of the pad is to be used for telescopes set up outside the obsy. Here is a Google Earth picture of where the pad will sit on my property. The yellow square on the right side of the image is the pad's location. North is at the top of the image. Use this image to get your orientation for the Pano below.

And here is the full Pano from that site. My best sky (from a light pollution aspect) runs from northwest to south southeast.