What are SIP's?

SIPs are high-performance building panels suitable for walls, roofs and even floors in residential and commercial buildings. The most common SIPs use expanded polystyrene (EPS) foam insulation sandwiched between two structural skins of steel or oriented strand board (OSB). The result is a building system that is very strong, predictable, energy efficient, and cost effective. Of the two systems, the superiority of the steel system is indisputable.

Steel SIPs (structural insulated panels) are engineered panels made from a dense core of EPS (expanded polystyrene) sandwiched between two exterior layers of factory painted galvalume steel, resulting in a solid one-piece component that provides structural framing, insulation, and exterior sheathing. Approximately 4’ wide, the interlocking panels are strong, light and easy to handle.

The technique of sandwiching a foam core between metal skins has been used in refrigeration technology for decades and many screen room additions and carports have been built using the panels. What is relatively new is their acceptance and approvals nationwide by building departments as a material suitable for home construction. SIP systems are now recognized by all major code organizations and have received the highest seismic rating available from California.

The panels are put through extensive and rigid testing to insure they continue to meet and exceed building code requirements for wind, live and dead loads, racking, and impact. They have been “hurricane tested”, and have proven to be stronger than block or wood frame construction, sustaining only very minor exterior siding damage in winds exceeding 140 mph, with no structural failures.

What are OSB SIPs compared to STEEL SIPs?

Presently, more people are familiar with OSB SIPs than Steel SIPs. They were the first SIP systems readily available, due to the use of inexpensive OSB and workability with conventional carpentry tools. While far superior to conventional framing, they still have some inherent shortcomings.

Unlike Steel SIPs, OSB SIPs must be meticulously sealed against water penetration, requiring messy two part foam sealing and a vapor barrier wrap. Also, the OSB skins are subject to termite damage. Because of their weight, expensive crane rental is incurred at the job site. Due to length limits and dead loads of OSB, the spans are limited without additional structural support.

Steel Skin SIPs eliminate all of these problems. They are light weight, impervious to moisture, termite proof, and offer increased span capabilities.

It is known that the wood framing in a building contributes more to flame spread than any other source except for furnishings. In strict fire testing of the steel skin insulated panels, the metal skins performed extremely well under the intense heat conditions and the fire-retardant expanded polystyrene foam core did not contribute to the spread of the fire.

In addition to the standard required testing, it is important to note that the solid core construction eliminates the "chimney effect" that causes fires to spread quickly through conventionally framed walls.

All testing was done in strict accordance with ASTM and UL testing procedures.