I Want To Use SIP Panels on My Next Project. Are They Covered in Building Codes?

I Want To Use SIP Panels on My Next Project. Are They Covered in Building Codes?

When deciding if SIP Panels are a good choice for your next construction project, it is good to know they conform to building codes, are incredibly strong, and extremely energy efficient, and used to build hundreds of millions of square feet of buildings each year.

Over the years, products are accepted or rejected by a combination of  public opinion, research, and practical application.  All play a role in determining if a product stays or goes.  Fortunately for SIP panels, the verdict has landed squarely on the side of sticking around.  They are not perfect, but they do enjoy very positive levels of acceptance. SIP Panels are, all in all, a great building product, technically sound, and written into the major residential and light commercial building construction codes. Even the international codes.  So, if you are wondering if SIP’s will “hold up” and produce a technically sound structure the short answer is yes.  As a matter of fact, if SIP Panels were not viable, then the 100’s of millions of square feet of building space built using SIPs each year wouldn’t exist.  

SIP Panels do have some drawbacks you should be aware of, however; these drawbacks are predominately production related constraints making them unavailable to most of the world and we outline those drawback in this article: Rationale for Building your own SIP Panels if you are in construction, especially internationally!

To better understand if SIP Panels are a good choice for your construction project you must have a rudimentary understanding of what SIP Panels are.  They are primarily made from two materials: a foam core and sheet material (sheathing) that serve as the interior and exterior walls.  The skins are bonded to the core and thus, the three pieces become a single structural composite panel.  After the panels are made they are cut to size and transported to the job site and assembled to create the building envelope.  The assembly process is very quick, a small house can be assembled in as little as a few days.  Here is a little primer document with sketches and graphics depicting the varied SIP Panel configurations and uses.  

Basic SIP Construction 

How strong are SIP’s and are they safe?

Sip panels are incredibly strong.  They behave much like an I-Beam and the thicker the panel the stronger it is.  In addition, SIP Panels offer great shear and out of plane flexural loading.  Their ability to resist bi-axial bending and lateral shear makes them acceptable for roofs and floors as well.  As a matter of fact, SIP Panels are acceptable as shear walls in all seismic design categories1.   

These performance characteristics also ensure high wind load and snow load resistance and the tallest structures constructed exclusively of SIP’s is 4 stories.  This means when you are building with sips, no secondary framing is needed except in the case of large open expanses of a building.  This makes them ideal for most typical small house designs where open expanses are not present and the structure is typically 1 or 2 stories tall.

To ensure safety, SIP Panels continue to undergo testing and inclusion into building codes.  The acceptable use of SIP panels can be found in the following codes and standards:

  • 2012 International Residential Code Section R613: Structural Insulated Panel Wall Construction
  • APA, The Engineered Wood Association (2007). “APA Product Guide: Structural Insulated Panels”
  • NTA Inc., “Evaluation of Code Compliance with 2006 and 2009 International Building Code and 2006 and 2009 International Residential Code”
  • Structural Insulated Panel Association, “SIPs in the IRC”

What applications are covered by codes?

“Structural insulated panel walls are included in the IRC for wall panels that are 4.5-in. and 6.5-in. thick and up to 10-ft. tall. In addition, the building site must be limited to a maximum design wind speed of 130 mph”; a maximum roof snow/live load of 70 psf 2.

Use this map as a guide, consult local conditions and codes for compliance.  If you are in a wind zone rated at 130 mph or less then SIPS can be used in your project.

 building code wind map

What are the benefits of having SIPs included in the building codes?

“For buildings inside the IRC Section R614 parameters, the stamp of a licensed engineer is not required for approval in jurisdictions that have adopted the International Residential Code. The IRC recognizes structural insulated panels as equal to other building systems in the Residential Code.” 2

Will I be able to produce code-approved SIPs without an ICC-ES evaluation report?

Manufacturers are not required to have a registered ICC-ES evaluation report to produce SIPs for applications within the parameters of Section R614. Although an evaluation report is not required, Section R614 requires that all structural insulated panels be manufactured under a quality control program approved by a third-party quality assurance agency that is accredited by the International Accreditation Service. 2

How thermally capable are SIP’s?

SIP Panels are one of the most widely used and generally accepted products to use to achieve high insulating value in buildings.  SIPS are constructed with foam cores and these foam cores provide most of the insulating properties. The two types of cores most frequently used are polystyrene and polyurethane.  Of the two, polyurethane has the higher rating.  Also, SIP Panels are used to produce LEED certified housing and “net-zero” housing.

 

Thickness EPS PUR
Density in Panel (lb/ft3) 0.90 2.3-2.5
4-1/2″ 13.1 22.7
6-1/2″ 19.9 35.1
8-1/4″ 26.0 46.0
10-1/4″ 32.9 NA
12-1/4″ 39.8 NA

 

When purchasing panels or making panels using the IADDIC system, you will be getting polyurethane construction foams.  Not only do these construction foams provide excellent insulation values but they are extremely condensed expanding 20-40 times when used.

One question we often get about codes is from people wanting to understand the codes in their area.  It is impossible to know about codes everywhere especially internationally.  However, if your building complies with the IBC/IRC then the use of SIPS is allowed. It is up to you to determine if the building meets your local codes.  If the building meets the code then the panels should meet the code as well.

Notes:

1.0 National Institute of Building Science “http://www.wbdg.org/resources/sips.php#rcas” 2.) SIPs in the IRC “http://www.sips.org/technical-information/sips-in-the-irc”

Richard Grabowski
Adequate housing and shelters are more than just products; they provide security, enable sustainable development, unite families, and help establish stable communities. Our focus at IADDIC is to bring the best technology, at the lowest cost, in the highest volume we can to make affordable housing indeed affordable.
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