Re-Roofing a Geodesic Dome

[jloomis]

I am working on a Geodesic Dome Re-Roof. I did the construction several years ago to 2 attached buildings. (both vented with cora ridge and doing fine) 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

[ransley]

Foam roofing is a way to go. If there is no moisture damage he probably doesnt need it.

[RicodJour]

Spray applied polyurethane foam roofing is good stuff if the building is designed to deal with the moisture from inside the building. It totally changes the look of the building, and maybe that's wanted or not. Whether the additional expense and change in appearance is desired is up to the owner.

big caveat is that moisture from inside the building will condense inside the batt insulation or, more likely, right on the plywood sheathing. If extreme care was taken to seal all gaps and penetrations, and a vapor barrier paint was applied to prevent moisture from migrating into the insulation space, there'd be a fair chance that it would have good longevity.

R

[Edward Hennessey]

JL:

If you are primarily looking for exterior ventiliation solutions on the new re-roof, here are some things to think on. I have seen wind turbines on domes, though the look flattering. Solar chimneys would also help with the venting and cooling. There are as well various passive, thermostatically-triggered panel openers which are used in the greenhouse industry which may be of interest to you directly or as a modficable base. If someone hasn't already adapted them to geodesics, it would be surprising. There may be a combination dormer/light pipe and, if not, it wouldn't be hard to vent some available light pipes which would also, of course, help with illumination; lastly, think of flat, shielded fan units.

Regards,

Edward Hennessey

[Dick Keats]

Would installing an air exchanger help?

Foam roofing is a way to go. If there is no moisture damage he probably doesnt need it.