huangyhg

structural insulated panels
i've been reading about sips (structural insulated panels), and they seem very impressive for use in walls, floors and roofs. has anyone got any good or bad experience with these to share? different foams are used for the core, most use osb for the exterior, although some now come with sheet rock or exterior cladding already mounted. any insights appreciated.
check out our whitepaper library.
i was brought into a problem with a structure in australia constructed almost entirely with "sandwich panel" as we usually call this product. walls, floors, support beams and columns were all made of the same material.
however because it was a building having 16 sides, and because there was no facility for movement within the wedge-shaped roof segments it had a serious (and continuing) roof leakage problem, caused by thermal diurnal movement. the metal deck facings heated up very substantially during summer days and expanded. but there was no means of relieving this expansion movement. the facings buckled in some areas; sheared in other areas at junctions with parapets (actually the radial support beams) and generally created a nearly insurmountable structural problem.
another problem was the large thermal gradient across the panel which caused, variously, complete separation of the upper face from the polystyrene core, distortion of the panel by warping and where spearation occurred to those radial support beams there was a loss of beam integrity.
this all sounds like the story of a bad product but this isn't so. the problem was with the architecture and engineering. by redesigning to allow proper control joints for thermal movement the building could have been structurally sound and innovative.
i guess it's no surprise, i was acting for the solicitor in a legal case against the d&c team!
anthony tugwell
project director & consulting engineer - just relocated to australia
i agree with anthony...you must certainly understand the thermal characteristics and their interrelation with the structure for sips.
panelized construction has been around for quite a while in various forms. within the past 5 years or so, wood panelized construction has been pushed by the awa-the engineered wood association. you might check their website for some additional info.
pay particular attention to jointing (thermal shorts) and connections (thermal shorts, bending loads in fasteners that normally carry shear only). look also at the curling effects of thermal gradients across the panels.
careful an thoughful design can make this system workable.
ron

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]