in praise of field modifications

Our steel erectors are back for a few days to finish up some details. John (left) and Mike put up the last pieces of trim along the top ridge of the upper roof. They modified the trim to act as a raceway protecting the cables for the photovoltaic panels, eliminating the need for the clunky PVC box that normally accompanies the Uni-solar panels. This improvisation is one of the best field modifications in the project, so far.

utilities and services

Earlier this week, our photovoltaic (solar-electric) installer connected the wires for the p/v panels through the holes we'd carefully drilled through the steel trim at the top of the upper roof. These wires will be concealed beneath, and protected by, the final piece of trim that gets installed as a cap over the top edges of the roof's standing seams. Once the cap trim is in place, the roof will be finished.

trim

Our steel erectors, Mike and John, have finished installing most of the steel trim on the outside of the house. The trim provides a clean finish at places where the building materials have been cut roughly and where we've used expanding foam insulation to fill the gaps between the walls and roof. Trim is generally a decorative element, whereas flashing is used to keep water from infiltrating the house. At tin box, both the trim and the flashing are made from sheet metal which has been finished in the same Kynar coating as the wall panels.

international style

Eytan Fichman, my undergraduate thesis advisor - and the very model of a mentor whose example as an educator is never far from my mind - sends this photo of "the Vietnamese precedent for tin box" in Haiphong. It's nice to see so many of our formal gestures, like shed roofs and deep overhangs, appearing in a building that seems to be designed around functional concerns and the simple modular dimensions of available materials.

Boy do I wish we could have ducks, too.

fenestration

Big day at tin box today. Astor Windows began installing our windows. Along with Steelcom completing the installation of the exterior wall panels, this is a huge step forward for us.

We'll write about the windows and doors at length, soon, including Holly's trip to the CGI factory. For now, we're just reveling in our gorgeous fenestration...

peeling

The insulated wall panels have a layer of plastic on the exterior side that protects the finish. Peeling it off is somewhat addictive, and makes for a fun, Saturday afternoon family activity.

color

A quick site visit this evening with friend of tin box, Peter Lang. It was an unusually overcast afternoon in Miami, but that gave way to a beautiful sunset, which gave us a chance to see the house's silver skin react to the rapidly changing crepuscular colors. When we decided on a silver metallic finish, we anticipated that it would respond elegantly to the changing light conditions. So far, so good.

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.

more wall panels

The insulated steel wall panels are going up at the garage and the front porch, and by the end of next week we should have most of the wall panels in place. We'll write about the installation process (and sing the praises of our installers) later. Right now, we wanted to share some photographs of the panels in different light conditions, to show how the color and texture change with the weather and time of day...

wall panels, continued

The erection crew put up the first two wall panels this afternoon, in between solving one problem (the screws provided were too short) and running into another (the third panel would line up in a spot with no supporting girts or other structure). Nonetheless, the installed panels give us a good idea of how the exterior is going to come together. The silver finish (seen here with Holly peeling back the protective plastic wrap) is really beautiful. Because it reflects so much of the ambient light around it, the silver finish appears to change color as the viewer moves. It also changes as the light fluctuates between direct sunlight and the indirect light of an overcast sky.

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 panels complete

Late this afternoon, the steel erector installed the last of the insulated roof panels. There's still a lot of work to do on the roofs, including trim, gutters and photovoltaic panels, but it's really nice to see all the panels in place.

roof, again

An addendum to our earlier post about the upper roof. The first photo shows the upper roof with its b-deck sheathing, while the lower image shows the insulated roof panels installed. One difference is reflectivity; the galvanized b-deck is almost mirror-like, and reflects light much more brilliantly. In fact, it casts the kind of harsh glare that caused the Miami Marlins to revise the finish on their new stadium in Little Havana (see below). The duller finish of the galvalume paint on the roof panels, however, moderates the amount of sunlight reflected into our neighbors' houses, which is a good thing.

The other difference has to do with grain and pattern. The wider spacing of the standing seams in the roof panels makes the roof - and the house as a whole - seem less broad than it did when the roof was covered with just b-decking.

We're curious to see how the roof changes when we install the photovoltaic panels. In the meantime, bonus photos of Miami's biggest tin box, the new Marlins stadium:

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:

lumber

We've designed the house to avoid using softwood lumber as much as possible. This is the kind of wood that's typically used for framing (as 2x4s and 2x6s) or furring (the thin pieces of wood used to attach gypsum drywall to concrete block walls) in conventional construction. The two major problems with using softwood lumber in Miami are termites and mold.

However, it turns out we need to use a few 2x4s in 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:

partitions, p.2

In the week since we wrote about laying out the interior partitions, Pedro and his crew have completed most of the framing. The light gauge studs and track, which were supplied as part of the prefabricated system (along with the heavy steel frame and the insulated exterior panels), go up pretty quickly. The studs are easy to cut, carry and fasten, and they have holes in them to allow plumbing and electrical lines to be laid easily. The metal studs also have the environmental advantage of being made largely from recycled steel.

action photos

Steel construction makes for some pretty cool photos.

Here, one of the erection crew is trimming some of the roof decking. Of the scores of panels of B-decking used in the house, only two needed to be trimmed. This efficiency - less material used, less waste on site, lower transportation costs - is one of the advantages to prefabrication.

One disadvantage is the need for specialized (read: expensive) machinery, like boom cranes...

roof decking complete

The erectors completed the roof decking this morning. We're now ready for the insulated roof panels to go up (then wall panels, then windows and doors). The house is looking pretty cool.

decking

Our erector started installing the roof decking yesterday. These gorgeous corrugated sheets are High Shear B Deck (HSB-36), a structural roof decking that comes in 36" wide and 1.5" deep sheets. The decking is fastened to the z-purlins with TEK screws (which don't need a pre-drilled hole), and will act as a structural diaphragm under the insulated roof panels, which are also structural. Together, the decking and roof panels will deal with the combination of tensile, compressive and shear forces generated by hurricane force winds. They will also support the weight of the vegetated roof that we plan to add someday.

The B Deck will also make for a great ceiling, in combination with the z-purlins...