Replies

1. 
   wisjim | Feb 07, 2018 09:31pm | #1

   What kind of dome? Geodesic made of standard lumber sizes? Sprayed concrete on an inflatable form? Type of construction makes a difference in your options. I've know people who have built them, and the geodesic dome using standard lumber meant lots of cutting to fit fiberglass insulation in all the odd triangular spaces, with the end result being a mediocre job that I would not want to attempt again. The concrete dome ended up with spray foam which was expensive and hard to deal with when done. Both of the types had LOTS of wasted space because most people want vertical partitions and walls.

2. GBA Editor
   Martin Holladay | Feb 08, 2018 04:09am | #2

   Fortneri,
   If you bought a dome kit from a manufacturer, you should contact the manufacturer for advice.

   If you are following instructions form the early 1970s -- the era of Lloyd Kahn's Domebook 2, a resource which is available online here -- or if you have inherited a dome from that era, the short answer is that the hippie dome-builders were inexperienced and making up the details as they went along.

   These hippie dome-builders were neither roofers nor insulators. They tried fiberglass batts, they tried rigid foam, and they tried spray foam. As you might guess, spray foam was the most effective from a thermal performance standpoint, but presented finishing and fire safety issues.

3. Expert Member
   Dana Dorsett | Feb 08, 2018 12:58pm | #3

   I'm aware of at least one concrete dome home that was insulated with a continuous exterior layer of 3lb spray polyurethane foam.