A Stately Pleasure-Dome

[samuel coleridge]

I am interested in building an adidtion to my home. Basically, it is a pool house, but due to zoning regulations it will be structurally connected to the main house. I want the design to be domed. Here is a link to a conservatory with a dome to give a general idea: http://www.oakleafconservatories.co.uk/categories/104/default.aspx

The differnce is that the conservatory is designed for England, where sunshine is a rare and precious commodity, and I live in California. A glass roofed conservatory is the last place you want to be during the pool season - you would burn to crisp. So I plan a solid dome with insulation, probably a copper roof, and windows in a drum beneath the dome, so that the windows will catch direct sun only in the morning and evening when it is not so hot, and not during the hottest part of the day.

So my dome will have to be framed, sheathed and insulated. I am thinking an octagonal dome, 8 or 10 foot wide across parallel sides. I am looking for guidance on how to do this in a cost effective way. By making the base octagonal rather than circular, I eliminate compund curves, so sheathing in plywood shoud be a snap. The framing is more complicated.

One way to build this would be stressed skin plywood, using "stich and glue" like a boat hull. That would probably be strong enough, but I doubt if my local building inspector will sign off if there is no framing.

Another possiblility is Radius Track, which supplies kits with custom built curved steel frames, tension and compression rings, connectors etc. Here is a link: http://www.radiustrack.com/domes.asp
I think this would work jsut fine, but it is not very cost effective for such a small dome - they are geared up for bigger projects.

Another possibilty is a kit with glulam frames from Roof Domes LLC http://roofdomes.com/map I have no doubt their product would work just fine, but have not been able to get them to respond to a request for a quote yet, so I am not sure how cost effective it would be.

Another possiblity is to purchase custom made glulam beam from a glulam manufacturer, and do the rest myself. This doesn't seem like too big a job, and likely to be very economical. So far, however, I haven't been able to get a manufacturer to reply to my request for quotation. Does anyone have ideas on who would manufacture a small run of custom curved glulam beams at a resonable price?

Finally, does anyone have other suggstions for how to frame this dome at a reasonable cost?

Many thanks to all.

[djswan]

I picked a bad week to quit "stich and glue"

Building an upside down boat, eh?

I've never tried a "stately look", sounds like fun.

[djswan]

How about a cold molded dome out of reclaimed redwood? cedar? Does the job pay for a trip to the south east coast to find some cyprus knees?

are there other options?

[barryhunter]

You might consider a fiberglass dome such as at Shalimar
http://www.strombergarchitectural.com/projects/shalimar

Reminds me of one of my favorite poems by Colridge

"In Xanadu did Kubla Khan
a stately pleasure dome decree
Where Alph the sacred river ran
Through caverns measureless to man
down to the sunless sea"

[Kiley Jin]

Samuel,

I think steel frames are the way to go. If you really think that the dome would be strong enough built frameless "stitch and glue," then you can't possibly go too light on the frames, so light steel framing is the way to go.

Check out Priceless Perfect Curves: http://www.pricelesssteel.com/New/CurvedProducts/CurvedProducts.html

They sell curved steel track which they tout as being suitable for domes if you put it on its side. They will bend to your specifications and offer it in various gauges. 20 gauge and above is considered "strcutural," but they sell it all the way up to 12 or 14 gauge.

If you make each rib of the dome out of double pieces of the curved track, with the open side of the track faceing out (sideways), you can run ordinary steel studs between the ribs (ring frames) to get the 16 inch centers you need. With an octagoanl base as you propose, and no compound curves for the sheathing, the studs will not need to be curved at all and you can buy stock material and cut to length on site.

By the time you screw together steel ribs and ring frames, then screw plywood sheathing to them, the whole is going to be very strong. Think of an interior wall built with light steel framing, which is solid if constructed properly. Then think that you are using 20 gauge or thicker frames as oppossed to the 25 gauge often used for partition walls, plywood rather than drywall, and add the inherent strength of domes and the arches which the ribs form. It'll be plenty solid and done with pretty convential materials and design, so your building inspector should be happy.

Those studs will be very cheap. The curved track is going ot be a little more expenssive, but I think still a lot cheaper than custom curved glulam, not to mention lighter and easier to work with.

Overall, I think this is going to be the cheapest way to get what you want, and construction should be pretty straightforward. I love the idea - it will definitley look distinctive. Maybe you can post photos when you get it built?

Kiley

[samuel coleridge]

baryyhunter - Yes, you have correctly outed me on my screen name and the source of the stately pleasure dome! That line is burned into my brain for some reason. The formality of the language of the poem doesn't match its content. I envision a classic, if not formal, structure, but intended for leisure and recreation, so "stately pleasure dome" sort of sums it up. I suposse fiberglass would work, but I prefer more traditional materials.

djswan - Undoubtedly cold molded would work, but it would be a lot of work, and I would still have the framing problem. I don't think the building inspector is going to sign off without framing.

Kiley - Eureaka! You have found it! I think steel framing is the way to go. The link you posted looks promising. If you or anyone else knows of an alternative source for curved steel framing like this, I would love to know about it and compare prices. I will post photos when I have them, but don't hold your breath - it may be a couple of years. Thanks, Kiley!

[djswan]