Stan Dimmick - Structurally Insulated Panels

Stan Dimmick, the President of Korwall Industies, Inc., has been touting the virtues of structurally insulated panels, or SIPs, since 1958.  He has weathered the storm of criticism against the use of SIPs as nothing more than a cheap, experimental building material to be used for mobile homes, to the painfully slow acceptance of the use of SIPs as a legitimate building system, offering clear advantages to traditional “sticks and bricks” construction.  

The origins of the first SIP dates back to the 1930’s when engineers from Forest Products Laboratory (FLP) in Madison, Wisconsin theorized that by sandwiching insulation between two boards or skins and adding additional framing, you could pre-make panels for construction to be used as load bearing walls.  The first prototype was created and  for the next 30 years SIPs were manufactured and sold in the marketplace.  


Frank Lloyd Wright was one of the first known architects to use SIPs on his Usonian houses, and in the early 1950’s one of Wright’s students, the son of the founder of Dow Chemicals, decided to use Styrofoam between the skins resulting in the first foam core panel.

                                                         Usonian House

Stan Dimmick and his partner jumped into the foam panel market in the late 50’s by manufacturing lightweight sandwich panels with a honeycomb core and plywood skin for the mobile home industry.  Over the next 20 years the building industry changed, and by 1973 the Korwall product had evolved into a panel made of “two layers of wafer board laminated under pressure to a core of expanded polystyrene (foam).”  The trademarked Korwall, Korfloor and Kor-Roof products are in use today for residential and commercial applications. 

Korwall invested a great deal of time and money in the testing of its SIPs including the hiring of an engineer to administer a number of structural integrity, load bearing and durability tests, and to submit all findings and data to a several  professional groups including the Council of American Building Officials (CABO) in an effort to help satisfy any reservations about using SIPs for construction.   With the help of believers like Stan who have stayed the course of their convictions, the building industry began to embrace the use of SIPs as an alternative construction material.   

Some of the Benefits of SIPs:

Two to five times stronger than conventional materials

Continued savings on heating and cooling cost

Lifetime warranty (offered by Korwall)

Easy to construct, short learning curve

40% shorter construction time, less labor cost

50% less framing results in lower cost on materials

Less construction waste

Minimal thermal loss for added indoor comfort and moisture control

Stan says that it has taken him 44 years to get the “attention of home buyers and architects” about the benefits and legitimacy of SIPs.  Some might say the industry has finally caught up to Stan.  With a growing awareness in some of the key principals outlined in the LEED rating system, such as, energy efficiency, reduced waste and building materials, durability and maintenance, today’s homeowner is more savvy about the “true cost” of homeownership and is interested in making the right choice in building materials for the life of the home not just the construction of the home.      

Stan understands this growing awareness, and while his story is now told to a more receptive audience, he has been a pioneer in the SIPs industry for years and an inspiration to others interested in sustainability.  For those who believe in the people and businesses that are conscientious about their work and their impact on the world, we owe Stan a debt of gratitude for being a visionary who stayed the course. 




Korwall Industries, Inc: http://www.korwall.com/SIPs/PanelHomes/Default.htm

Structurally Insulated Panel Associations (SIPA) - http://www.sips.org/