SIP roofs and SIP walls in the building industry are short hand for Structurally Insulated Panels. Basically a layer rigid foam sandwiched between two layers of plywood (typically oriented strand board, or OSB) with integral structural members (2×6, 2×10, etc.). Some companies adhere the finished ceiling material like tongue and groove pine on the inside face as shown below. These panels are made to the specific structural and insulating requirements of your home, the thicker the panel, the greater the R Value. The construction time can be reduced because the panels arrive ready to tilt up or fly in on a crane and are pre-cut to fit.
Photo: Eagle Panel
Photo: Precision Panel
The Following is a discussion on the Pros and Cons of Structurally Insulated Panels (SIPS) by Steve Hancock at The Log Connection up in beautiful BC, Canada. It’s a good summary of some of the SIPS applications and benefits. Thanks Steve for sharing your insights. We specify SIPS on many of our projects and have used Precision Panel locally, Eagle Panel in Illinois, and Enercept in South Dakota.
The Log Connection takes great care to ensure that our homes are handcrafted with the best techniques for ensuring a weather tight seal. The SIP panel (Structural Insulated Panel) system works in very will in some applications and for some people…. but not everyone. A large part of the decision is understanding all of the pros vrs. cons of the product and making sure they work for your design. We have outlined a number of areas that we review and discuss with our clients when making the decision of conventional framing vrs SIP panels.
ROOF PROS:
It’s our opinion that the the use of the SIP panels on the roof system is an efficient way to install a roof system quickly. The more simple the roof line, the more practical the application. In most situations, the panels can be made to easily span between our roof logs and be completely roofed in a just days. The thicker the panel the higher the R-value. If made the same thickness as a conventional roof the rating is about 30% and higher depending on the manufacture. The panels are pre-cut at the assembly plant so the on site waste and clean up is lower with the use of the SIPs
Photo: Precision Panel
ROOF CONS:
Most of our home owners are as interested in the look of their home as they are in the efficiency of the products. On of the largest issues our home owners have is the accent lighing you see in the ceiling of nearly all our homes. It is not yet possible to install a recessed or pot light into a SIP panel. In areas with heavy snow loads the design of long overhangs are be limited to that of the panel.
WALL PROS:
The wall systems stand and install quickly on our post and beam homes and the upper gable ends of the stacked log packages. The pre-cut panels* are ready to install when delivered to job site.
Openings are pre-cut for window and doors, minimal framing or trim work should be required. The on site waste and clean up is lower with the use of the SIPs
Photo: Enercept
WALL CONS:
The largest issue we have with the wall panels is that the exterior sheathing of the the panel is cut flush to the edge. We have a system that allows the exterior sheathing and interior drywall to EXTEND INTO the posts. This creates an impenetrable weather seal and no drafts at the joint. When butting a SIP up against the post there will eventually need to be a weather block/ trim installed to stop the draft. Hanging small pictures will be fine but without heavy artwork and shelving should may not be possible due to no solid stud to fasten. Installing unplanned electrical boxes is a huge hassle and requires cutting and patching of the panels. Pre-plan and you will be fine.
* Rarely will the SIP manufactures visit the job site to acquire and verify the as build measurements. Therefore they will not assume any responsibility if the as built conditions are not 100% CADD prefect.
To sum it all up, the SIP panel it’s a great product when used with the right conditions with reasonable expectations. We encourage the conventional stick build system for our stacked log, and the post & beam homes. The SIP panel is recommended with our timber frame homes.
Steve






the simple fact that wood treatments can dramatically extend the life of the wood is a very “green” attribute indeed—in a life cycle analysis, it lowers the environmental costs of re-harvesting (and re-treating, and re-shipping and re-installing) replacement wood products. However, each wood treatment method has its merits, and each one has features that can make it more or less green. Let’s take a closer look by first reviewing a brief history of wood treatment.
attributes have earned the ProWood Micro formulation 




