Article 1037044 of alt.home.repair: Path: news.misty.com!not-for-mail From: nicksanspam@ece.villanova.edu Newsgroups: alt.home.repair Subject: Re: Radical idea for Supporting Porch Roof Date: 2 Aug 2008 19:46:38 -0400 Organization: Villanova University Lines: 67 Message-ID: References: <3da05816-04b2-4c58-8880-a74e59187617@y38g2000hsy.googlegroups.com> NNTP-Posting-Host: acadia.ece.villanova.edu X-Trace: max.inside.misty.com 1217717061 5742 153.104.44.130 (2 Aug 2008 22:44:21 GMT) X-Complaints-To: abuse@misty.com NNTP-Posting-Date: Sat, 2 Aug 2008 22:44:21 +0000 (UTC) Xref: news.misty.com alt.home.repair:1037044 RicodJour wrote: >What keeps a cable supported porch roof from acting like a huge sail... Leonard Bachman's new Integrated Buildings book describes a house in Almere, near Amsterdam... This radical design was a winning entry in a competition for demountable housing. Most designs for High-Tech residential projects work to identify transferable tecnnology from commercial building systems. This house takes the reverse approach. It is actually a residential laboratory for working out a construction scheme the architects were developing for a commercial project... Working with store-bought pieces, the architects erected the house themselves in only three days. One of them, Jan Benthem, lived in it with his family during the five-year design award period. Foundation: Four prefab concrete industrial floorslabs act as pads to support a steel space frame of 2m bays 2m above the ground with adjustable jacks. The space frame uses thin tube members flattened at the ends and is bolted together on 5 mm octagonal welded steel connectors. Vertical members: Roof is supported on 3 sides by frameless glass walls and supporting glass fins. The glass is made structural by bearing carefully on the large thick panels and then bracing them with fins to prevent lateral deflection. Horizontal spans: Roof span rests on inverted truss of steel angles and tension cables. Roof grid is vertically tied back to floor by 2 interior cables to resist uplift. Roof: Loose laid EPDM membrane on 50 mm extruded polystyrene insulation over profiled steel metal deck... The roof is supported by 3 tensioned stainless steel cables spanning from the deck side wall to the enclosed bays and 2 more cables spanning the other direction. This makes a 2 meter grid of cables under the metal roof deck matching the joints of glass and supporting fins. It both holds the roof up and holds it down. Pairs of steel angle run under the exposed metal deck on the same grid. Adjustable struts lift the middle of the roof from the 6 intersection points of the cables, forcing down against the cables and up against the steel angles. The cable, struts and angles form a shallow and whispery 2-way tension truss, preventing deflection in the roof and perhaps introducing positive camber to insure rainwater drainage. Additionally, the center two strut points are tied back to the floor in the middle of the room by vertical steel cables to counter wind uplift forces. These 2 tieback cables pull directly down from the adjustable struts and are secured to the floor at points where it is directly supported by the space frame undercarriage. Brief: The competition emphasized a concern about the impact of permanent architecture. It asked if society would not be better served by having a portion of its buildings designed as deployable temporary structures to be erected, disassembled, warehoused as components, then erected again. This was postulated as a more intelligent response to changing needs and land use patterns than heavy investment in monumental buildings which constantly become obsolete and burdensome. Accordingly, the guidelines stipulated that entries must be removable in five years and leave no scars on the site. To assure the ease of construction and commissioning, the rules required that the houses could readily be assembled by the user... Nick