I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

"jloomis" wrote in message
...
I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis
Not an uncommon problem here in the "Frozen North". Causes are different but
the results are the same. Replace the batts with closed cell rigid foam. If
that is not possible, ensure that the vapor barrier is in good repair. Seams
taped, tape around the switch and plug boxes. Be sure to use good waterproof
tape, such as freezer tape that is impervious to moisture and cold. Well
perhaps in your area the cold is not a problem. Installing a good
dehumidifier on the heating system is a good way to go. Consider installing
an air handler that will exchange the interior air with outside air on a
regular basis. Some will do that as ofter as once each 24 hours, depending
on the size of the structure. Any air exhange or pure venting system coupled
with a good dehumidifier should reduce the problem to manageable levels...
Good luck... Nice looking dome BTW...

Dave D

Call Bucky and see if he has any ideas...

David.

He's dead......I tried....Apparently he died from "mold"
jloomis
"David F. Eisan" wrote in message
...
Call Bucky and see if he has any ideas...

David.

It may be too late now, or it may be done already. But...

If the sheet rock on the ceiling doesn't have a vapor barrier, it
should. Most of the water vapor in an attic area comes from the air in
the living space coming through the ceiling sheet rock. The water
barrier sheet rock has aluminum foil glued to the hidden surface.

Other fixes... Paint that surface with a water vapor paint. Or, paint
the inner surface of the ceiling with water barrier paint. The last is
the easiest to do.

Some history... I've built two houses and used the foil covered (alo
fire rated) sheet rock in both. In both cases the city building
inspectors told me it would cause the rafters to rot. They also disliked
foil covered insulation in an attic for the same reason. I think they
are wrong. Water vapor doesn't come into the attic from the outside and
go through the sheet rock to dissipate. The motion is normally in the
other direction. I have plenty of vents to the outside and much less
vapor coming through because of the foil. Our current home is 28 hears
old and the trusses are just fine.

I wonder if it would be effective, when building a geodesic dome,
drilling a number of holes through the triangular wood framing of the
roof and installing vents in some. The holes wouldn't significantly
weaken the structure and would allow air to move from one to another and
find its way out a vent. How did Bucky deal with this problem?

Bill

jloomis wrote:
He's dead......I tried....Apparently he died from "mold"
jloomis
"David F. Eisan" wrote in message
...

Call Bucky and see if he has any ideas...

David.

"jloomis" wrote in message
...
I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?

Don't do a thing. Think of it as job security.

B.

Good Questions.
I am not building this dome but re-roofing it. Many people think that the
roof leaks when it actually is condensation on the inside. We normally
provide an airflow above the insulation and out through the roof vent or
whatever vent you have.....ridge vent. In this case the existing dome, is
completed.....Interior and exterior.
The shingles are old and weathered.....(comp type) Moisture damage is found
under the old shingles....
By installing batt insulation and not providing any insulation, we have a
problem. (past construction techique)
I like the idea about foil backed rock......trouble is, it is already
in......
I like the idea of painting with a good quality moisture sealing paint.....
Now that may be an answer......
Thought about drilling holes, but that is like shooting a shotgun at the
problem.
We live in a cool moist climate, and with the warm air inside, lots of
moisture is created......
It does get into the ceiling areas.......especially non vented types.
I have repaired many houses with faulty venting situations, and badly
installed insulation.
I am still puzzled with the dome.......It is not a good design for "batt
insulation" needs venting.
Thanks for the thoughts......
jloomis
"Bill Rubenstein" wrote in message
...
It may be too late now, or it may be done already. But...

If the sheet rock on the ceiling doesn't have a vapor barrier, it should.
Most of the water vapor in an attic area comes from the air in the living
space coming through the ceiling sheet rock. The water barrier sheet
rock has aluminum foil glued to the hidden surface.

Other fixes... Paint that surface with a water vapor paint. Or, paint
the inner surface of the ceiling with water barrier paint. The last is
the easiest to do.

Some history... I've built two houses and used the foil covered (alo fire
rated) sheet rock in both. In both cases the city building inspectors
told me it would cause the rafters to rot. They also disliked foil covered
insulation in an attic for the same reason. I think they are wrong.
Water vapor doesn't come into the attic from the outside and go through
the sheet rock to dissipate. The motion is normally in the other
direction. I have plenty of vents to the outside and much less vapor
coming through because of the foil. Our current home is 28 hears old and
the trusses are just fine.

I wonder if it would be effective, when building a geodesic dome, drilling
a number of holes through the triangular wood framing of the roof and
installing vents in some. The holes wouldn't significantly weaken the
structure and would allow air to move from one to another and find its way
out a vent. How did Bucky deal with this problem?

Bill

jloomis wrote:
He's dead......I tried....Apparently he died from "mold"
jloomis
"David F. Eisan" wrote in message
...

Call Bucky and see if he has any ideas...

David.

On Fri, 4 Apr 2008 18:33:26 -0700, "jloomis" wrote:

I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

No suggestions, just a question:
Where is it located? The surrounding country is fantastic!


mac

Please remove splinters before emailing

jloomis wrote:

I am working on a Geodesic Dome Re-Roof.
snip

Just curious, you by chance realted to a guy named Lionel Loomis?

He was a neighbor of mine at one time back in Cleveland.

Lew

Hello Lew,
Have relatives in Pennsylvania......
Wilksbarre. Thats where my grandpa lived.....coal miners....
Not sure about Cleveland....
jloomis
"Lew Hodgett" wrote in message
news:4cYJj.725$4Q1.185@trnddc06...
jloomis wrote:

I am working on a Geodesic Dome Re-Roof.
snip

Just curious, you by chance realted to a guy named Lionel Loomis?

He was a neighbor of mine at one time back in Cleveland.

Lew

Hi Mac,
That is 10 mile river area.....very rural part of northern calif.
North of Fort Bragg, just past 10 mile bridge on highway 1.
The area is very rural, cow pasture, sheep, deer, salmon and steelhead
stream.
Mountain lion and bear also live back up in the hills.
The coast is very steep along highway 1, and very panoramic. Small town of
Westport north of there is a stopping spot when I go surf fishing this
spring......
jloomis
"mac davis" wrote in message
...
On Fri, 4 Apr 2008 18:33:26 -0700, "jloomis" wrote:

I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

No suggestions, just a question:
Where is it located? The surrounding country is fantastic!


mac

Please remove splinters before emailing

On Sun, 6 Apr 2008 07:15:46 -0700, "jloomis" wrote:

WOW.. I was thinking that the scenery looked like Tennessee or something..lol
I used to run through Fort Bragg on bike rides from the bay area, years ago..

Rode the skunk train once and that was enough tourist stuff for me..lol

We use to take a bike-camping vacation every year and usually started by taking
the 101 up north and crossing over to hiway 1 at Fort Bragg...
Wonderful route to the Oregon coast, if you like winding roads and rugged
coastlines.. (we did)

Hi Mac,
That is 10 mile river area.....very rural part of northern calif.
North of Fort Bragg, just past 10 mile bridge on highway 1.
The area is very rural, cow pasture, sheep, deer, salmon and steelhead
stream.
Mountain lion and bear also live back up in the hills.
The coast is very steep along highway 1, and very panoramic. Small town of
Westport north of there is a stopping spot when I go surf fishing this
spring......
jloomis
"mac davis" wrote in message
.. .
On Fri, 4 Apr 2008 18:33:26 -0700, "jloomis" wrote:

I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

No suggestions, just a question:
Where is it located? The surrounding country is fantastic!


mac

Please remove splinters before emailing



mac

Please remove splinters before emailing

"jloomis" wrote:

Hello Lew,
Have relatives in Pennsylvania......
Wilksbarre. Thats where my grandpa lived.....coal miners....
Not sure about Cleveland....


Lionel was a transplant, but I forgot from where.

Very easily could have been Pennsylvania or even "West By God".

Lew

"mac davis" wrote in message
...
On Sun, 6 Apr 2008 07:15:46 -0700, "jloomis" wrote:

WOW.. I was thinking that the scenery looked like Tennessee or
something..lol
I used to run through Fort Bragg on bike rides from the bay area, years
ago..

Rode the skunk train once and that was enough tourist stuff for me..lol

We use to take a bike-camping vacation every year and usually started by
taking
the 101 up north and crossing over to hiway 1 at Fort Bragg...
Wonderful route to the Oregon coast, if you like winding roads and rugged
coastlines.. (we did)

Oh Yes,
I moved to Fort Bragg in 1975
Bought a 5 acre parcel up in the "boonies" all redwoods and no
neighbors......
Raised 2 boys here, and still travel and love to come home.
I know about the windy roads....We say it keeps the rif raff out.
Lots of bikers up here and my son works in Eureka, up north, @ a bike shop
as a mechanic.
He is into downhill bicycle, and racing, and trail.....
Yep, Fort Bragg has changed but not alot.....
Skunk Train is still running, and the steamer is out this summer.....
they are going to do "the skunk run" bicycle ride.....race......fun.....
jloomis

On Sun, 6 Apr 2008 17:10:04 -0700, "jloomis" wrote:

Very pretty country...
About the only thing I miss since moving to Mexico is big trees....

One of the places we traveled to one last time before we moved was to the Avenue
of the Giants...

"mac davis" wrote in message
.. .
On Sun, 6 Apr 2008 07:15:46 -0700, "jloomis" wrote:

WOW.. I was thinking that the scenery looked like Tennessee or
something..lol
I used to run through Fort Bragg on bike rides from the bay area, years
ago..

Rode the skunk train once and that was enough tourist stuff for me..lol

We use to take a bike-camping vacation every year and usually started by
taking
the 101 up north and crossing over to hiway 1 at Fort Bragg...
Wonderful route to the Oregon coast, if you like winding roads and rugged
coastlines.. (we did)

Oh Yes,
I moved to Fort Bragg in 1975
Bought a 5 acre parcel up in the "boonies" all redwoods and no
neighbors......
Raised 2 boys here, and still travel and love to come home.
I know about the windy roads....We say it keeps the rif raff out.
Lots of bikers up here and my son works in Eureka, up north, @ a bike shop
as a mechanic.
He is into downhill bicycle, and racing, and trail.....
Yep, Fort Bragg has changed but not alot.....
Skunk Train is still running, and the steamer is out this summer.....
they are going to do "the skunk run" bicycle ride.....race......fun.....
jloomis



mac

Please remove splinters before emailing

"jloomis" wrote in message
...
I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

It's long been a dream of mine to build a geodesic dome house. My wife has
been balking at the idea, but she just took a cursory glance at your photo
and said, "Looks nice," and walked away. Rock and roll!

I'm sorry to hear about the water problem, especially since I live in Ottawa
where cold air meeting warm is a serious issue. I've actually been
wondering about having two concentric domes, just so there's room for
insulation and "breathing". I spoke casually with an architect friend a
couple of weeks ago and he discouraged the idea of using shingles, favouring
metal instead. In your case that would only exacerbate the problem.

Until now my biggest concern was fire, since I heard it can spread quickly
in this kind of structure. The water issue might just trump that one by a
fraction. But somehow my gut tells me there is a good solution to all of
these problems. Just not sure what it is yet.

Thanks for your post! I'd love to hear and see more, if you're inclined to
share it.

- Owen -

Hi Owen, I have worked on many homes, ventilated and not......
The "not" are the problem homes.....
I now provide a good "air space above insulation" and that can be done by
providing air flow with lightweight plywood over the insulated
structure.....
Also new building codes are making it hard to create this space due to
fire.....
so, solid insulation is the next step......
It is a tough building aspect........
jloomis
"Owen Lawrence" wrote in message
...
"jloomis" wrote in message
...
I am working on a Geodesic Dome Re-Roof.
I did the construction several years ago to the 2 attached buildings.
The Geodesic Dome is nasty.....There is no ventilation in the traingle
shapes....It was insulated with standard batt insulation and sheetrocked
interior......No place for the water vapor to vent.....
The owner knows it, I really cannot fix the problem other than re-roof
it.....
What a job......
All the cells are enclosed.......
What can you do?
any ideas welcome....
jloomis

It's long been a dream of mine to build a geodesic dome house. My wife
has been balking at the idea, but she just took a cursory glance at your
photo and said, "Looks nice," and walked away. Rock and roll!

I'm sorry to hear about the water problem, especially since I live in
Ottawa where cold air meeting warm is a serious issue. I've actually been
wondering about having two concentric domes, just so there's room for
insulation and "breathing". I spoke casually with an architect friend a
couple of weeks ago and he discouraged the idea of using shingles,
favouring metal instead. In your case that would only exacerbate the
problem.

Until now my biggest concern was fire, since I heard it can spread quickly
in this kind of structure. The water issue might just trump that one by a
fraction. But somehow my gut tells me there is a good solution to all of
these problems. Just not sure what it is yet.

Thanks for your post! I'd love to hear and see more, if you're inclined
to share it.

- Owen -

"Owen Lawrence" wrote

It's long been a dream of mine to build a geodesic dome house. My wife
has been balking at the idea, but she just took a cursory glance at your
photo and said, "Looks nice," and walked away. Rock and roll!

I'm sorry to hear about the water problem, especially since I live in
Ottawa where cold air meeting warm is a serious issue. I've actually been
wondering about having two concentric domes, just so there's room for
insulation and "breathing". I spoke casually with an architect friend a
couple of weeks ago and he discouraged the idea of using shingles,
favouring metal instead. In your case that would only exacerbate the
problem.

Until now my biggest concern was fire, since I heard it can spread quickly
in this kind of structure. The water issue might just trump that one by a
fraction. But somehow my gut tells me there is a good solution to all of
these problems. Just not sure what it is yet.

It has been many years since I looked into Geodesic domes. I even met
Buckminister Fuller once without even knowing it was him.

The solution that one builder used that I talked to was to just spray
everything with fiberglass. He would go to a local boatbuilder, rent one of
those cherry picker tools that would allow the sprayer to position himself
over the structure and let him spray it. You can pick any color too!

And fiberglass, being what it is, deteriorates over time. So you need to
restore it every so many years. But you can put it on extra thick at first.
I am certain that fiberglass has improved since the time I looked at this
option.

As for the insulation, how about the sprayed foam insulation? I have no
ideas how it would handle the water/condensation issue. But is a super good
insulator, makes the structure very quiet and can be applied quickly.

You might look at these two ideas if you want to build a dome.

"Lee Michaels" wrote in message
. ..

"Owen Lawrence" wrote

It's long been a dream of mine to build a geodesic dome house. My wife
has been balking at the idea, but she just took a cursory glance at your
photo and said, "Looks nice," and walked away. Rock and roll!

I'm sorry to hear about the water problem, especially since I live in
Ottawa where cold air meeting warm is a serious issue. I've actually
been wondering about having two concentric domes, just so there's room
for insulation and "breathing". I spoke casually with an architect
friend a couple of weeks ago and he discouraged the idea of using
shingles, favouring metal instead. In your case that would only
exacerbate the problem.

Until now my biggest concern was fire, since I heard it can spread
quickly in this kind of structure. The water issue might just trump that
one by a fraction. But somehow my gut tells me there is a good solution
to all of these problems. Just not sure what it is yet.

It has been many years since I looked into Geodesic domes. I even met
Buckminister Fuller once without even knowing it was him.

The solution that one builder used that I talked to was to just spray
everything with fiberglass. He would go to a local boatbuilder, rent one
of those cherry picker tools that would allow the sprayer to position
himself over the structure and let him spray it. You can pick any color
too!

And fiberglass, being what it is, deteriorates over time. So you need to
restore it every so many years. But you can put it on extra thick at
first. I am certain that fiberglass has improved since the time I looked
at this option.

As for the insulation, how about the sprayed foam insulation? I have no
ideas how it would handle the water/condensation issue. But is a super
good insulator, makes the structure very quiet and can be applied quickly.

You might look at these two ideas if you want to build a dome.

I like the idea of "quiet", since I want to put a grand piano under this
dome. One goal, however, is that the structure be easy to maintain. My
only experience with sprayed foam insulation is with my new windows. It's
time consuming cutting through that stuff if you must, and it never really
comes off any surface it touches.

Whatever approach I use, I'd like to build a prototype, first a shed, and
maybe a new workshop. First, I'll need land, which isn't getting any easier
to find now that the baby boomers are all retiring.

- Owen -

On Wed, 9 Apr 2008 07:46:08 -0400, "Owen Lawrence"
wrote:


"Lee Michaels" wrote in message
...

"Owen Lawrence" wrote


As for the insulation, how about the sprayed foam insulation? I have no
ideas how it would handle the water/condensation issue. But is a super
good insulator, makes the structure very quiet and can be applied quickly.

You might look at these two ideas if you want to build a dome.

I like the idea of "quiet", since I want to put a grand piano under this
dome. One goal, however, is that the structure be easy to maintain. My
only experience with sprayed foam insulation is with my new windows. It's
time consuming cutting through that stuff if you must, and it never really
comes off any surface it touches.

Whatever approach I use, I'd like to build a prototype, first a shed, and
maybe a new workshop. First, I'll need land, which isn't getting any easier
to find now that the baby boomers are all retiring.

- Owen -

Came in 1/2 way thru this thread so have no idea if my observations
have already been suggested/reported. You do need ventilation for
whatever roof structure you propose to use.
What are your plans for finishing the interior of the dome? Drywall,
panelling, T&G wood?- They're all going to be time-consuming
major pain-in-the-ass installations, given the geometry of the
construction; or did you intend to leave the insulation exposed?
If the insulation is to be left exposed you're still going to need a
vapour-barrier to prevent moisture from within the house (cooking,
showers etc.) from entering the insulation and defeating its purpose
unless you plan to use the sprayon the OP was mentioning.




At any rate you need a roof ventilation system- check with your
local government as to what is required by your local building code.
We are in the final stages of completing a new house (acting as our
own general contractor) and what is required by code here- British
Columbia, Canada- is a continuous venting system from soffit to
roof peak. There's a formula regarding number of vents based upon the
square footage of the roof. I realize that with a dome there aren't
going to be any soffits but a continuous path for roof ventilation
can still be easily provided; just install roof vents as low on the
side of the dome as you feel comfortable with, and install more vents
closer to the "peak" of the dome.
That being said, you'll still require channels to conduct the
colder, outside air across the upper surface of the insulation layer
and out thru your upper vents. In our case (conventional woodframe
construction but with vaulted ceiling throughout) we accomplished this
airflow by having the insulators install pieces of small ductwork to
the interior side of the roof decking. I cannot for the life of me
remember what this ductwork is called but it comes in pieces 4' long
and in widths to accomodate the distance between the roof trusses and
provides a tunnel, as it were, between the interior side of the roof
decking and the exterior side of the ceiling insulation. The
fibreglass batt insulation we used (R-28) is a crush-fit to the
ventilation tunnels which are about 1 and 1/2 inches deep.


Sorry if any of this has been covered before, but best of luck
with your project. I know when we took the decision to build it
seemed a daunting task but has turned out to be a truly rewarding
experience.

Paul

Existing Dome......
Already been done.......in 1980
It is a mess, and I roofed it, giving the owner some ideas concerning the
problems.
It is sheetrocked, and insulated.....
The Dome builders must have built many of these before they started getting
complaints.
I told the owner to call Oregon Domes and relay the problem to them.....
They built it, and are still in business but I am sure with better improved
ways to vent the roof.
All roofs need venting............except for solid insulation installed
tightly.......
jloomis
wrote in message
...
On Wed, 9 Apr 2008 07:46:08 -0400, "Owen Lawrence"
wrote:


"Lee Michaels" wrote in message
m...

"Owen Lawrence" wrote


As for the insulation, how about the sprayed foam insulation? I have no
ideas how it would handle the water/condensation issue. But is a super
good insulator, makes the structure very quiet and can be applied
quickly.

You might look at these two ideas if you want to build a dome.

I like the idea of "quiet", since I want to put a grand piano under this
dome. One goal, however, is that the structure be easy to maintain. My
only experience with sprayed foam insulation is with my new windows. It's
time consuming cutting through that stuff if you must, and it never really
comes off any surface it touches.

Whatever approach I use, I'd like to build a prototype, first a shed, and
maybe a new workshop. First, I'll need land, which isn't getting any
easier
to find now that the baby boomers are all retiring.

- Owen -

Came in 1/2 way thru this thread so have no idea if my observations
have already been suggested/reported. You do need ventilation for
whatever roof structure you propose to use.
What are your plans for finishing the interior of the dome? Drywall,
panelling, T&G wood?- They're all going to be time-consuming
major pain-in-the-ass installations, given the geometry of the
construction; or did you intend to leave the insulation exposed?
If the insulation is to be left exposed you're still going to need a
vapour-barrier to prevent moisture from within the house (cooking,
showers etc.) from entering the insulation and defeating its purpose
unless you plan to use the sprayon the OP was mentioning.




At any rate you need a roof ventilation system- check with your
local government as to what is required by your local building code.
We are in the final stages of completing a new house (acting as our
own general contractor) and what is required by code here- British
Columbia, Canada- is a continuous venting system from soffit to
roof peak. There's a formula regarding number of vents based upon the
square footage of the roof. I realize that with a dome there aren't
going to be any soffits but a continuous path for roof ventilation
can still be easily provided; just install roof vents as low on the
side of the dome as you feel comfortable with, and install more vents
closer to the "peak" of the dome.
That being said, you'll still require channels to conduct the
colder, outside air across the upper surface of the insulation layer
and out thru your upper vents. In our case (conventional woodframe
construction but with vaulted ceiling throughout) we accomplished this
airflow by having the insulators install pieces of small ductwork to
the interior side of the roof decking. I cannot for the life of me
remember what this ductwork is called but it comes in pieces 4' long
and in widths to accomodate the distance between the roof trusses and
provides a tunnel, as it were, between the interior side of the roof
decking and the exterior side of the ceiling insulation. The
fibreglass batt insulation we used (R-28) is a crush-fit to the
ventilation tunnels which are about 1 and 1/2 inches deep.


Sorry if any of this has been covered before, but best of luck
with your project. I know when we took the decision to build it
seemed a daunting task but has turned out to be a truly rewarding
experience.

Paul

I was chatting with an architect this morning about your situation. He
mentioned that walls don't have ventilation, yet we make them the way we do
and they work. So why not make the roof that way, too? But whatever way
you do it, you have to make sure your vapour barrier has high integrity.
Even the smallest crack can result in a problem.

- Owen -

"jloomis" wrote in message
...
Existing Dome......
Already been done.......in 1980
It is a mess, and I roofed it, giving the owner some ideas concerning the
problems.
It is sheetrocked, and insulated.....
The Dome builders must have built many of these before they started
getting complaints.
I told the owner to call Oregon Domes and relay the problem to them.....
They built it, and are still in business but I am sure with better
improved ways to vent the roof.
All roofs need venting............except for solid insulation installed
tightly.......
jloomis
wrote in message
...
On Wed, 9 Apr 2008 07:46:08 -0400, "Owen Lawrence"
wrote:


"Lee Michaels" wrote in message
om...

"Owen Lawrence" wrote


As for the insulation, how about the sprayed foam insulation? I have
no
ideas how it would handle the water/condensation issue. But is a super
good insulator, makes the structure very quiet and can be applied
quickly.

You might look at these two ideas if you want to build a dome.

I like the idea of "quiet", since I want to put a grand piano under this
dome. One goal, however, is that the structure be easy to maintain. My
only experience with sprayed foam insulation is with my new windows.
It's
time consuming cutting through that stuff if you must, and it never
really
comes off any surface it touches.

Whatever approach I use, I'd like to build a prototype, first a shed, and
maybe a new workshop. First, I'll need land, which isn't getting any
easier
to find now that the baby boomers are all retiring.

- Owen -

Came in 1/2 way thru this thread so have no idea if my observations
have already been suggested/reported. You do need ventilation for
whatever roof structure you propose to use.
What are your plans for finishing the interior of the dome? Drywall,
panelling, T&G wood?- They're all going to be time-consuming
major pain-in-the-ass installations, given the geometry of the
construction; or did you intend to leave the insulation exposed?
If the insulation is to be left exposed you're still going to need a
vapour-barrier to prevent moisture from within the house (cooking,
showers etc.) from entering the insulation and defeating its purpose
unless you plan to use the sprayon the OP was mentioning.




At any rate you need a roof ventilation system- check with your
local government as to what is required by your local building code.
We are in the final stages of completing a new house (acting as our
own general contractor) and what is required by code here- British
Columbia, Canada- is a continuous venting system from soffit to
roof peak. There's a formula regarding number of vents based upon the
square footage of the roof. I realize that with a dome there aren't
going to be any soffits but a continuous path for roof ventilation
can still be easily provided; just install roof vents as low on the
side of the dome as you feel comfortable with, and install more vents
closer to the "peak" of the dome.
That being said, you'll still require channels to conduct the
colder, outside air across the upper surface of the insulation layer
and out thru your upper vents. In our case (conventional woodframe
construction but with vaulted ceiling throughout) we accomplished this
airflow by having the insulators install pieces of small ductwork to
the interior side of the roof decking. I cannot for the life of me
remember what this ductwork is called but it comes in pieces 4' long
and in widths to accomodate the distance between the roof trusses and
provides a tunnel, as it were, between the interior side of the roof
decking and the exterior side of the ceiling insulation. The
fibreglass batt insulation we used (R-28) is a crush-fit to the
ventilation tunnels which are about 1 and 1/2 inches deep.


Sorry if any of this has been covered before, but best of luck
with your project. I know when we took the decision to build it
seemed a daunting task but has turned out to be a truly rewarding
experience.

Paul