Structural Insulated Panels (SIP) can create a strong, well-insulated, airtight, building envelope. They can, however, be unforgiving when it comes to moisture management. Most SIP dry slowly if or when they get wet, so back-vented claddings, robust flashing details, meticulous sealing of penetrations, and effective spot/whole house ventilation are all essential.
SIP Corner Details
Three different options for panel overlap at corners are shown here. Corner Detail A is the easiest, while Corner Detail B affords a somewhat tighter seal against moisture and wind. Corner Detail C shows the use of a short panel section to form the overlap. Depending on your framing system, this detail may enable you to use materials more efficiently. Note that in Corner Details A and C, holding the top panel back 1/4-inch from the other panel can yield a better space to inject foam sealant to make an airtight joint.
NOTE: The GBA SIP details consist of 90 pdfs. Currently, the details are not available as dwg files. These 90 details are copyrighted by Green Mountain Panel and included in the GBA Construction Detail Library with express permission from Green Mountain Panel. All of the SIP Details were drawn by Steve Baczek and reviewed by Peter Yost for Green Mountain Panel, the same team that developed all of the other GBA details.
To see the SIP details with the step-by-step installation procedures, download the Green Mountain Panel Installation Manual.