“Stewart Speaks” is a monthly educational piece written by Stewart Elliott, our resident timber frame expert. Stewart Elliott has been Woodhouse’s Senior Team Leader for the Midwest and Western Regions since 2014. One of the longest standing members of the original Northeast timber framing community, he is known as the “groovy grandfather” of the industry. His historical knowledge and expertise captivates and enlightens our customers, staff, and building partners.

This month, Stewart will touch base on what Structural Insulated Panels (SIPs) are and the benefits of building with them.

What are Structural Insulated Panels (SIPs)?

SIPs are kind of like a “building sandwich”: there are two rigid oriented strand board (OSB) skins holding together an inner layer of polystyrene or polyurethane. SIPs help Woodhouse homeowners by improving not only the overall quality of their homes, but also their quality of life – they reduce construction time, lower energy costs, create an allergen-free environment, and safer in the event of an accident.

To better understand how SIPs are made, think of really sturdy cardboard that is hard to bend. This rigidity comes from the corrugation (or the tight ridges that look like wrinkles) between the two pieces of cardboard paper. Each side of the cardboard is supported by the other, making them very hard to bend. Airplanes, surf boards, snow skies, and countless other products follow the same manufacturing method of simple laminated rigid skins (metal, OSB, fiberglass, vinyl, concrete) and a separating core (made from rigid foam, honey comb paper, straw, or light weight wood such as balsa).

Building with SIPs

There are many benefits to building with SIPs; for starters, they are very versatile. The strength of the panel is directly related to the thickness of the panel, resulting in many varieties of SIPS to be used for a variety of scenarios. For example, highly insulated panels keep heating and energy costs down, so they would be used in a northern climate as opposed to warmer locations. SIPs can be made from various materials, such as polyurethane and EPS foams, which can allow lighter SIPs to be stronger and heavier SIPs to be weaker. A good analogy to keep in mind is the snuggly warmth of a down jacket versus the functional warmth of a wool coat.

You can arrange to have SIPs arrive at the building site pre-fabricated or precut by CNC machines, which reduces installation time. These SIPs range in size anywhere between 4ftx8ft to 8ftx24ft and can be cut to the sizes and shapes needed to create a structure.

For more in-depth information about SIPs, check out our other SIPs feature, the “The Inside Story of Structural Insulated Panels (SIPs)” which further explains the reasons they are so highly acclaimed and why Woodhouse uses them as a standard feature in their designs.