Star Dome 2-C

A 20 ft diameter dome made from 2 x 4 wood and heavy duty pvc hub connectors.
The star window frame is 2 x 6, extending outward and offset beyond the roof and used for checking stength unde snow,wind, and roof loads.

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OSB panels were nailed on, then tar-felt roofing paper and wire mesh were placed on the osb roof deck panels. Next the initial "brown coat" of stucco was applied and let dry. A final waterproof layer of stucco finishes the dome roof.

Owner's Commentary:
Hello, Ernie.
Thought you would like to read this message to the head of the Regional
Building Department.  The crew came in and finished the last bit of "brown
coat."  They will do the finishing coat in a couple of weeks.  In the
meantime, I am going to keep watering the cement to have it cure before the
finishing coat as it won't be getting any more moisture.  Curing will stop.
So now is the time to get it to harden.  Watering a couple of times daily
should do the trick.  The layer is probably one to six inches thick.  Except
below the star, the stucco extends to the edge of the concrete pad,
minimizing the possibility of leaks around the base.  You would not believe
how strong the shell has become.  The weight is much greater than I
anticipated but that should not be a problem.  One thing for sure, it is not
going to go anywhere.  The vertical expansion is most interesting . . .

This shed could be easily converted into a guest house.  It would also be
easy to build a slightly smaller dome inside and to create a double wall for air to
circulate or to provide super foam insulation.

You are going to have to stop by and see it !!  Because of the scaffolding,
there is no way that I can get good pictures now.  That will have to wait
until the finishing coat and the window are in place.  It is an amazing
structure but it would not be for everyone to build . . .  not bragging . .
.  just advising .

Hope all is well.
Date: 22 May, 1999 7:27 AM

Hello, Ron*!
It has been a long time since that get-together with you and Don.  So, I
would like to share some observations with you.  IT'S ALL GOOD!!  Relax and
enjoy it!

Right after the permit was issued, thanks to you, I started installing the
144 panels that make up the "skin" of the dome.  Since I used construction
adhesive together with 2-inch deck screws every four inches or less, I had
to work when the weather did not affect the properties of the adhesive.
The calendar has been clicking.
During that time, we had tremendous winds and I took that opportunity to
make measurements of any deflections caused by the wind.  I could not
detect any despite the fact that I used a long arm down from the apex that
amplifies any horizontal distortion of the dome.  Why simulate a horizontal
asymmetrical load when Mother Nature provides one???  The observation was
sufficiently conclusive for my purpose.

Last week, following a lath inspection by John [good man . . .  keep
him!], we began the application of stucco.  We started with the standard
stucco thickness that would have provided a faceted surface.  I monitored
the three-dimensional displacement of a plumb bob at the end of the x-y
amplifying arm.  The z-axis measurement was not amplified.  After failing
to detect any displacement, I decided to go for the "rounded look" to approach
a perfect 5/8 sphere.  I continued to monitor the plumb bob.  Even with
asymmetrical loading and the amplifying arm, there was no measurable
displacement along the x-y plane.  However, I began to detect a rise along
the z-axis . . .  How could that be??? . . .  The next morning, the plumb
bob had dropped . . .  What's happening???? . . .  What to do ???  Like
Patton said: " if in doubt, charge" !!!  So, we charged as I monitored the
plumb bob.  After the sun came up and we began the second  horizontal slice
of stucco [there are four] , the plumb bob started to come up . . .  Ah,
there was no need to be concerned . . .  the z-axis motion [about one
quarter of an inch] is directly related to temperature!! . . .  Since then,
I have monitored the plumb bob several times daily and that is what is
happening.  Since the frame is made of wood and essentially unaffected by
temperature variations, the stucco must be sliding - however slightly -
overthe OSB panels.
Now that the dome is covered with stucco, it has an even greater feeling of
strength and solidity.  The weight has increased appreciably but my
"floating thin concrete slab" is holding up very well without fissures of
any type . . .  no hairline cracks . . .  unlike the slab in my basement
poured by a licensed contractor.

So, I am very pleased with that type of structure which reminds me of the
trulli [plural of trullo] homes in southern Italy.  Italians have been
building those for centuries but I bet that the Building Code does not
cover them and your staff would be hard-pressed to approve them.  I mailed you
some articles and pictures covering those interesting structures.  No, I am
not going to apply for a permit to build trulli!

However, if I were to build a new house in a disaster-prone area such as
South Florida, California and Oklahoma, I would really be tempted to
combine the Trullo concept with the Bucky geodesic dome approach.  Several
interconnected domes surrounding a courtyard come to mind.  That would
provide safety, light, airiness and simple construction.  I would use
thicker struts to provide greater insulation or go with a double wall.  Oh
well, maybe in my next life, after I see what they have in heaven !!

Enjoy your week-end and let me know when you need to take a lunch break
awayfrom your office.

*Fictional names are used to protect privacy.