I am building a custom observatory with a warm room and I'm having some trouble designing the interface between the dome and the flat roof. I've included a rendering of the overall design, my plan for framing the roof, and how I'm thinking about securing the mounting ring, so let me know if they seem like they would work.
I was planning on making the opening in the roof 91in, which is what Explora Dome says the diameter of the mounting ring is, and placing the ring on top of the roof sheathing (so the ring is flush with the opening) and then fastening it to the roof joists with metal straps like with the 10x10 metal building. However, I notice the the instructions for the 10x10 wood building (which I am not building) calls for a smaller roof opening at 86in instead of 91in. Is this purely to accommodate the plywood mounting ring? I got a call from ED saying it would be 12 weeks until it was ready so I have time to figure things out.
Also, my dad has a commercial roofing company in Florida and since it's a small building he said he would come up and do a liquid urethane roof for me, so it would be professionally flashed and sealed. I'm just wondering what others have done when installing an 8' ED onto a custom flat roof. More specifically, what diameter is your roof opening, and how did you secure the aluminum mounting ring to it? Or would I be safer to just build the wood mounting ring?
(Drawings/diagrams/photos would be very helpful)
Thanks in advance for your input!