Originally written: Mar 2004
In my small corner of the world we are seeing much more interest in SIPs both from the consumer and the architectural sectors than we ever hoped for. It is poor science to make projections on such a small statistical sample, but interest from another entirely unlikely quarter gives me good reason to have my heart soar like an eagle when thinking of the immediate future of SIPs.
I (we, the SIP Brotherhood) have received endorsement from none other than Frank Lloyd Wright. Well, not exactly. He is dead. In fact, very dead, having passed away to the great Architect in the Sky in the spring of 1959. However; to the extent that he continues to live through his works and ideas, he is not only still alive, but arguably still remains the most progressive architect out there.
Wright, after the long drought of the Great Depression, in 1935/36 in his mid sixties, spread on the table for us all: Fallingwater, The Johnson’s Wax Building – each one of which could be seen as the zenith of one’s career – and a small $5,000 house; the Jacob’s residence. Not in any way to detract from the contribution of the other two, I believe the little 1500 square foot building was his greatest work. It launched his “Usonian” series and contained so many “firsts” that it makes your head spin;
1. First radiant hydronic slab heat
2. First carport
3. First plywood panel non-load-bearing walls
4. First “composite/built-up” roof system
5. First lighting/electrical raceway built-in
6. First compact central “chimney” kitchen
And that’s not all! But this is more than enough for our purposes. (I really recommend you do some research and check out these little Usonia jewels!)
…I guess you get the idea. A real architectural and technological breakthrough!
Yes, I know this is an article about SIPs. I’m getting there, a little patience, please.
So the items of great interest for us are numbers 3 and 4.
Wright actually designed these babies to built “upside down;” that is, from the roof down! There were masonry piers and short walls – usually brick – that were built first on top of the slab and then the plywood and plank composite walls were to be inserted under the roof. Apprentices who “cheated” on Wright and reversed this process and were caught were severely dressed down and sometimes – fired! These walls were seen as enclosing panels that completed the thermal envelope, but were not structural where clerestory glass ribbons sat between them and the underside of the roof. They were of sandwich composite construction, comprised of horizontal 1 x 12s and battens screwed together over a ¾” plywood core. Today, I’m certain Wright would have welcomed SIPs as superior thermal enclosures that would accept the fastening of his unique exterior weather-skins and interior paneling. Wright was clearly into the large sizes his composite wall panels could attain, and I’m sure he would have great affinity for the jumbo SIPs.
Most interesting of all are the Usonia roofs, number 4 on our “Hit Parade” of firsts. Wright developed a “composite” roof structural system consisting of three layers of 2 x 4s with the center layer perpendicular to the other two adding up to a nominal 12 inch deep structure. This enabled him to have a wooden space-frame-like “panel” that could span in both directions or even work with his hexagonal grids at 60 degrees. These roofs were the technological “key” to the Usonia designs. Glass could go from floor to ceiling and other traditionally required beams, girder, purlins and framing was – for the most part – eliminated. This system allowed for glass clerestories to be located at the top of almost all walls. This “floating ceiling” effect was exploited by Wright to create paradoxical spaces that, with their thick roofs and large overhangs, conveyed a powerful sense of shelter and security, yet at the same time, with the eye travelling from inside to outside along the ceiling plane, delivered a sensation of strong engagement with the outside. When Wright proudly proclaimed that he had “destroyed the box,” he was really saying that his spaces did not have the overwhelming sense of containment that was the hallmark of traditional western building.
Now it’s perfectly clear to me that there are d—n few roof framing systems out there that give you the opportunity to catch ‘em up and support ‘em wherever your fluid plan just happens to let you! One can see why Wright had to invent such a system when you experience his buildings. A brick pylon here, a short wall there, a chimney, a post wherever! Not much in any regular position holding up the roof! I have tremendous sympathy for those apprentices who, out of frustration, thought to put the walls up first.
Aside from a true space frame or curved shell construction SIPs can deliver this kind of span capability without even breathing hard. I know in my heart of hearts that Wright would have loved ‘em! His Usonia designs are so magical because they deliver experiences and sensations that ordinary stick framing just can’t economically match. The proof is that these built-up bi-directional roofs were trouble for Wright and his clients. Their structural performance depended upon the strength and stiffness of the connections between the layers of 2 x 4s and the stability of the wood framing members. Toe-nailing wasn’t a great way to achieve a really good connection and the wood itself experienced considerable shrinkage across the grain equal, of course, to the 12” of total depth. While the concept was more than clever in that it also allowed Wright to specify pitch into the build up so as to avoid ponding water on the roof, deflection due to connection movement would be excessive. Thus SIPs would have performed beautifully for Uncle Frank ( as we affectionately refer to him in our office ) as none of these problems would have occurred. I guess this is a clear example of being ahead of his time.
It wasn’t the only time Wright designed and detailed for materials that weren’t yet available. The Johnson’s Wax building had skylights and clerestories of glass tubes sealed parallel to each other. Too bad this was well before silicone caulk/sealant was invented. They leaked like crazy until they were finally sealed, decades after Wright’s death, with the silicone we now take for granted.
The issue here is that modern buildings, which are defined as those that don’t have a particularly strong sense of containment ( a solution based on the presumption that the outside world is not hostile ), and that encourage the occupants to engage their environment, use glass and opaque planes under a “floating” roof. SIPs excel as thermal and structural wall planes, but they can also be utilized as multi-directional roof planes. Supported on seemingly random points, as Uncle Frank would say, “ As a waiter supports his tray on the tips of his fingers,” SIPs can help you to create a home with a terrific sense of shelter, but also one that is in tune with the contemporary social outlook.
Originally written: Mar 2004
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