batt insulation

We've had most of the interior walls filled with batt insulation. We're using the insulation to help reduce sound transmission from room to room. We're expecting a 5 point increase in the STC rating (of sound transmission) due to the additional mass in the walls. The Johns Mansville fiberglas batts are made without formaldehyde, which is important for maintaining our health, and are made with glass that is at least 25% recycled.

The insulation has also produced some nice spatial effects...

foam insulation, continued

Spent some quality time Sunday with the family at the site, trimming back the expanding foam insulation that we've use to seal the gap between the wall panels and the roof panels. The foam cuts fairly easily, and the ladders help give us better leverage for peeling off the remaining plastic protective layer on the wall panels.

foam insulation

We spent much of Thursday and today spraying foam insulation into the gap between the wall panels and the roof decking. Normally, the insulated steel panel system completes the weather seal (and insulated envelope) with a boxed-out soffit detail at the roof, but we thought this configuration would make the roof look too thick and clunky, so we decided to use expanding foam  insulation to provide the moisture and thermal barrier between the wall and roof. So what is this stuff made of?

more wall panels

Our installer is making progress on the wall panels. They've put up about half the panels, but still have some tricky areas and a lot of trim to do in the coming weeks. For now, we're enjoying having a chance to see the front of the house (left, with the porch in the foreground) and the courtyard (after the break) take shape.

wall panels

For the last few days, our steel erectors have been preparing to install the insulated steel wall panels. At 3" thick, these panels are thinner than the roof panels, but still have an insulating value of at least R-24. Like the roof panels, they are held in place with clips designed to avoid breaking the thermal barrier, and they use two kinds of sealant (gooey stuff from a tube and self-adhesive strips) to maintain a continuous moisture barrier.

Preparing the panels and the frame is taking some time and care...

roof

Our steel erector set the insulated panels in place on the upper roof yesterday. These panels, each 42" wide, run the full 18' length of the roof slope in order to eliminate the kinds of lap joints that might leak. The standing seam joints between the panels also eliminate leaks (by raising the seam well above the roof surface) and hold the panels in place by crimping around the stainless steel clips that are screwed through the corrugated b-deck and into the z-purlins.

The installation process includes two kinds of sealants to complete the moisture and thermal barrier:

ductwork

Our mechanical contractor began installing ductwork this week. The segment in the living and dining rooms (pictured here) is the most prominent piece in the house, and it was the first to go up. It will remain exposed, along with the structure and the electrical conduit.

The ductwork has a layer of insulation between two walls of metal to keep the air as cool or hot as possible between the air handler and the register. This kind of ductwork is more expensive, but the insulation makes the system more energy efficient and prevents condensation building up on the ductwork, and the metal lining inside helps keep the air free of dust and mold.

The ductwork also responds beautifully to the changing light conditions inside the house:

roof panels

Our steel erector began putting the insulated roof panels up this week. Together with the insulated wall panels and the metal trim, this comprises the final layer in the prefabricated shell of the house. The panels themselves are pretty impressive:

roof

From the Kingspan factory in Deland, FL, comes this progress photo of our roof panels. Our roof uses KingZip insulated metal panels with a standing-seam joint. We chose 4" thick panels, which will give us an insulating value of R-32 (exceptional by Florida standards). We could have gone up to 6" thick, which yields R-48, but this would be a bit excessive in South Florida.

Each 42" wide panel will hold two solar panels, which adhere directly to the steel surface of the roof panels. The panels have a galvalume finish whose high albedo value (a measure of reflectivity) means they will reflect most of the sunlight that hits them, minimizing the direct heat gain.

The roof panels are cut to length in the factory, which helps eliminate on-site waste and reduce energy wasted in transit (one benefit to prefabrication). The pieces can come in lengths up to 52', the length of a flatbed truck. Our longest pieces are about 32'. We'll write more about the roof when it starts arriving, early next week.