Ann Edminster, M.Arch, LEED AP (a long time colleague) is a recognized international expert on green-home design and a principal developer of the LEED for Homes rating system. Here’s a story about Ann’s house in Pacifica, California, in interview format with Jim Gunshinian from Home Energy Magazine. This Q&A originally appeared in Home Energy magazine's January/February 2015 issue. You can view the full article on www.homeenergy.org.
Jim Gunshinan: Ann, Terry Nordbye, a Home Energy author, is consulting on an attic retrofit at your home.
Ann Edminster: I’ve lived in this house for 28 years, and it has been upgraded many times; it started life as a 1947 Sears Roebuck kit. It was pretty simple before I got my hands on it. Not so simple now.
I’ve always wanted to do what’s reasonable here, but not what’s heroic. My attic had a light dusting of something the color of dirt all over it—maybe ancient cellulose? Bits of fiberglass dotted the floor, looking like cake decorations. I’ve done just about everything else in the way of reasonable upgrades, so reinsulating the attic was just a project waiting to happen—waiting for the right people and the right insulation.
JG: How’s the project going so far?
AE: Terry’s been providing guidance for Don Kingery, a general contractor recommended to me by Andy Wahl, a home performance consultant and trainer who has also helped out on the project. I am an advisor for Havelock Wool, a manufacturer of New Zealand wool insulation, and they agreed to supply the insulation for the attic—finally, a product I can get excited about! But before we could lay down the insulation, we had to clear out the attic really well and air seal. We weren’t sure we could lay the wool over the existing knob-and-tube wiring, so we updated the electrical first.
The roof is low slope, about 3:12. It is hipped on two sides. There are skylight wells, a second-story addition, and a parapet wall. Part of the original roof had been chopped to create space for a deck. Like I said, not simple. We decided to take out the eave vents to create space for more insulation and allow for better air sealing, and added a new side vent through the parapet wall to make up for it and to provide access to the attic. This also enabled us to seal off the old ceiling hatch (another air leakage point).
Terry is an air sealing specialist. After the guys vacuumed and swept, Terry and the crew used gun foam and tape to fill in and cover any holes bigger than 1/8 inch or so. That’s where we’re at now.
JG: What’s next?
AE: Terry has a relationship with Western Colloid, and they want to try out a new elastomeric product Terry calls Product X. Terry has found that the gun foam doesn’t hold up so well over time, so to completely seal the attic, Terry is going to spray all over with the elastomeric product. It will take some time to dry, and then next week we’ll install the wool insulation.
This small attic project has turned into a major attic experiment! Terry will have lots of before-and-after blower door numbers to share when we’re done. We’re all quite excited about it. I call those of us who play with our houses this way the Let’s Try It at Home Club. There’s always another project around the corner. We may install a second solar array next. Stay tuned!
SH: I'm looking forward to hearing more about Product X!