What is a SIP [Structural Insulated Panel]?
What is a SIP?
Written by: Dave Stevenson
Welcome to Dave Stevenson’s inaugural SIP blog.
I happen to be one of those unfortunate members of the X generation, graduating in the ‘80’s and just barely missing the boat at the beginning of computer revolution. I bought my first computer at age 31 and have been frantically trying to catch up (and keep up) with all the hardware, soft ware, web portals, chat rooms, abbreviated lingo, ‘apps’, and social media sites, ever since. I would never have imagined myself participating in an on-line ‘blog’ a month ago, let alone being the author of my very own. I’m sure that many of you older builders out there reading this now can empathize with my plight and will allow me some time and leeway to develop this blog into something we can all gain valuable knowledge and expertise from.
This blog will be dedicated to Structural Insulated Panels (SIPs), or stress skin or sandwich panels as they are also commonly known. It is not my intent to use this blog as just another ‘on line’ sales avenue pitching the virtues of SIPs to a younger, more tech savvy group of builders; although no doubt many of these virtues will be touched on and will surely lead to rigorous and engaging topics of discussion for our forum. No, the main purpose of this blog will be to assist those builders who are already building with SIPs and want to add to their knowledge and refine their methods, and also to provide the confidence to those builders who have not tried SIPs yet to take the leap, by providing the best information and expert advice to ensure a successful completion.
Building with SIPs is certainly different than building with ‘stick frame’ systems as most builders have experienced on past projects. It’s comparable in some ways to my introduction regarding computers. It is a relatively new technology for many of you, and for this reason it is important to understand things like suitable SIP applications, design limitations, installation methods, and how other building materials interface with the SIPs; just to mention a few potential topics.
So let’s begin at the beginning –
A Structural Insulated Panel is composed of a solid, continuous core of rigid insulation that has been laminated or expanded between two sheets of substrate sheathing. The most common type of core insulation used in SIP fabrication is expanded polystyrene (EPS). The most common sheathing material is Oriented Strand Board (OSB).
The look of the OSB/EPS composition, or standard Plasti-Fab Insulspan SIP, is something akin to a giant ice cream sandwich. Regardless of the composition or ‘ingredients’ of the panel however, the common result is a strong, energy efficient building component that can be used for walls, floors and roofs of single family homes, multi-unit complexes and light commercial buildings.
Insulspan SIPs come in 5 standard thicknesses of 4 ½”, 6 ½”, 8 ¼”, 10 ¼” & 12 ¼” with a nominal R-value of R-4 per inch, and large sheets of OSB allow us to laminate ‘jumbo’ panels of up to 8’ x 24’. Although the panels can be manufactured and sold as ‘blank’ rectangular panels, the majority of Insulspan SIPs are pre-cut to exacting tolerances using 3D modeling and CNC fabrication. Edge relief as well as lumber spline connectors and headers are then incorporated into the panels to create a completely ready to assemble, pre-fabricated package.
There are some obvious benefits to SIPs when comparing against standard ‘stick frame’ construction. The panels are generally much quicker and easier to install and also provide superior thermal performance and air-tightness. The panels are fabricated in a controlled environment adhering to more stringent quality control than is possible for on-site stick frame construction. The Insulspan SIP manufacturing process includes a strict ISO 9001-2010 quality assurance program, which includes third party certification of the manufactured product, and all the project designs are sealed by a professional engineer who confirms the structural capacity of the panels in accordance with the applicable code requirements. The Insulspan SIP System has also been independently evaluated for code compliance – CCMC Evaluation Report 13016-R for Canada and ICC-ES Evaluation Report ESR-1295 for the United States.
The list of advantages goes on and on, but for the time being I just want to get the conversation started. No doubt, there will be plenty of comparisons made for and against SIPs, as well an endless supply of questions that should help keep the forum informative and compelling to participate in. I plan on uploading a new blog topic every 3 weeks, so please stay tuned for the next edition ‘Appropriate SIP Applications’, and in the interim I encourage you to join the conversation by posting your questions and sharing your experience and expertise.
Whew! I really didn’t know what a ‘blog’ was until they made me do it.
— Dave Stevenson
Plasti-Fab, Ltd.: Manufacturers of Insulspan SIPs