Sustainable Building Sourcebook
Chapter: Materials
 
Structural Insulated Panels
 
CSI Numbers: 07410 Preformed Wall & Roof Panels
 
Introduction:
 

Structural insulated panels (SIPs) are typically two outer layers of structural sheathing material separated by an insulated core. They are made in different sizes according to the job's requirements, and are typically referred to as Structural Insulated Panels (SIPs) or stress-skin panels.

Also see the Green Building Factsheets for introductions to this and other green building topics.

Structural Insulated Panel, Fig. 1

Typical structural insulated panel

 

 
At-A-Glance Notes:
 
Technology:
Many manufacturers make structural insulated panels. Quality control is becoming more consistent in the industry and product development is continuing.
 
Suppliers:
Available locally and regionally. Builders experienced with panels are available in Austin, although construction is fairly easy to learn for any standard builder.
 
Cost:
$1.75 to $2.75 per square foot or higher (material only). This can be slightly higher than conventional framing costs.
 
Public Acceptance:
Good
 
Regulatory:
Not all panels have been tested for code compliance. Make certain that the panel as a whole is code compliant, not just the components of the panel. This information is provided by the manufacturer.
 
Considerations:
 

Structural insulated panels replace the standard stud/insulation/sheathing wall system. Some panels have sheetrock mounted on the inside portion, and/or siding on the exterior. Most have sheathing such as OSB (oriented strand board) for facings.

Panels can be fabricated with three types of foam cores: expanded polystyrene (EPS), extruded polystyrene (XEPS), and urethane (polyurethane and polyisocyanurate are types of urethane). There are several options for facings: plywood, OSB, sheet-rock and metal.

Some suppliers offer exterior surface materials such as T-1-11 or fiber-cement siding. XEPS and most urethane foams use CFCs or HCFCs as blowing agents. EPS do not use any ozone-depleting chemicals. For credit from the Green Building Program for this option, EPS insulation or an alternative that has no ozone-depleting chemicals must be used.

OSB is an efficient use of wood and polystyrene is an effective insulation. However, this product is still very petroleum intensive in the final product. This product can also be a problem for chemically sensitive people. And there is the issue of deconstruction, as the laminated products cannot be easily separated.

Stuctural Insulated Panels, Fig. 2

This SIP has OSB as an exterior and interior sheathing material.

 

There is anecdotal evidence of insects burrowing in foam insulation as a way to find food. Some companies use borates as an insect barrier in the foam insulation. This is a preferred strategy for protecting the panels. Borates are also topically applied to the facings by some companies.

Structural grade adhesives should be used to bind the facings to the foam core. Use the manufacturer warranty as a gauge of the quality of the product. Poor adhesive qualities can cause panel failure. Select panels that are certified to meet building codes.

Structural panels offer very effective insulating qualities, rapid and sturdy installation, and consistent quality (minimizing waste). The use of OSB for facings is considered a positive use of wood resources. Panels are also used very successfully in roofing applications.

Structural Insulated Panels, Fig. 3

SIPs are generally lightweight and quickly erected.

Structural Insulateed Panels, Fig. 4

Using SIPs in a roofing application

 

 
Guidelines:
 

Ordering panels

  • Specify EPS with borate treatment for insulation or other non ozone-depleting insulation.
  • Use OSB facings. These materials do not contain urea formaldehyde.
  • Window and door openings can be provided by some manufacturers.
  • Some manufacturers produce pre-mounted drywall. Some panel manufacturers also offer exterior wall surfaces, typically T-1-11 or fiber-cement board.
  • Sandwich panels (two facings) and unfaced panels are available. Unfaced panels typically have studs in the insulation. Facings are added on-site.
  • Use panels that have structural grade adhesive linking the cores with the facings.
  • Panels can also be used as infill in a post and beam structure.

Panel details

Each manufacturer has their own method of panel connections: spline, interlocking stud, cam-lock, etc. Examine panel details from the manufacturer regarding installation because many variations exist. In connecting panels, choose systems that do not compromise the thermal qualities of the panel by creating a thermal bridge or "short circuit." There should be a small gap between panel sections so facings have room to expand. Wiring chases are typically provided by the panel manufacturer at specified distances along the panel. Caulk guns are a necessity. An oversized saw is useful for cutting panels.

If openings are not factory-supplied, a hot knife, hot wire, or router is used to make a channel for the wooden 2X inset framing. With EPS this is most quickly done with a router and a hot knife in the corners. This is a slow process with only a hot knife.

While storing panels, protect them from rain and keep them ventilated (particularly in hot, sunny locations) by using "sleepers" or spacers between panels. Stack panels so that the sequence of removal accommodates the order in which they need to be erected.

Structural Insulated Panel, Fig. 5

Sectional diagram of an SIP wall assembly

 

 
Resources:
 
Professional Assistance:

See "Engineers - Structural" in Yellow Pages

For SIPs Builders, use search term "SIPs" in the online Green Building Professionals Directory

 
Components/Materials/Systems:

Manufacturers using EPS (for other manufacturers see General Assistance section); some may also offer other foam insulation; not all may be interested in serving the central Texas area.

Agriboard Industries
8301 E. 21st St. North, Suite 320
Wichita, KS 67206
866-247-4267
316-630-9223
sales@agriboard.com
www.agriboard.com
Full-service panel fabricator using compressed straw between sheets of OSB

Enercept, Inc.
3100 9th Ave. SE
Watertown, SD 57201-1902
(800) 658-3303
info@enercept
www.enercept.com
Offers fully customized panels

Extreme Panel Technologies
475 East 4th Street
Cottonwood, MN 56229
(800) 977-2635
info@extremepanel.com
www.extremepanel.com
Manufacturer and supplier of SIPs, also offers design and construction support

The Fischer Group
1843 Northwestern Pkwy.
Louisville, KY 40203
(800) 792-7477
sales@fischersips.com
www.fischersips.com
Made with recycled materials

Foam Laminates of Vermont
P. O. Box 102
Hinesburg, VT 05461
(800) 545-6290
info@foamlaminates.com
www.foamlaminates.com
Online SIP manual available

Foard Panel
53 Stow Dr.
West Chesterfield, NH 03466
(800) 644-8885
info@foardpanel.com
www.foardpanel.com
Design and installation support, customized panels and other services

IB Panels
P. O. Box 723
50 West 100 South
Jerome, ID 83338
(888)-799-1398
www.ibpanels.com
Foam floor panels, wall panels and roof panels available

Insulspan
P. O. Box 38
Blissfield, MI 49228
(517) 486-4844
insulspan@insulspan.com.
www.insulspan.com

Regional Insulspan Sales and Services:
Panel Choice Inc.
211 Industrial Blvd.
Moore, Oklahoma  73160
Phone : (405) 799-8911
kent@panelchoice.com
www.panelchoice.com
Ready to assemble packages

Insul-Kor of California, Inc.
22230 Ottawa Rd
Apple Valley, CA 92308
(760) 961-0900
www.insulkor.com

J-Deck Inc.
665 North Hague Avenue
Columbus, Ohio 43204
(614) 274-7755
info@j-deck.com
www.j-deck.com
Roofing panels, company recycles manufacturing waste into panels

Korwall Industries, Inc
326 N. Bowen Rd.
Arlington, TX 76012
(817) 277-6741
info@korwall.com
www.korwall.com
Full-service panel fabricator, Korwall, Korfloor, and Kor-Roof with a variety of skins

The Murus Company
3234 Route 549
Mansfield, PA 16933
(570) 549-2100
info@murus.com
www.murus.com
Polyurethane foam with no formaldehyde, CFCs, or HCFCs

The Panel Factory
326 N. Bowen Rd.
Arlington, TX 76012
(817) 277-6742
info@panelfactory.com
www.panelfactory.com
Full-service panel fabricator, blank SIPs, processed SIPs, home packages and other structures

Precision Panel
1447 E. State St.
Eagle, ID 83616
(208) 939-2610
info@precisionpanel.com
www.precisionpanel.com

Precision Panel manufacturer in Texas:
Precision Panel South
Conroe, TX
(936) 499-5289
Paul_Knouse@PrecisionPanel.com

Premier Building Systems
3434 W. Papago St.
Phoenix, AZ 85009
(800) 240-6691
pligon@premier-industries.com
www.pbspanel.com
Largest SIPs manufacturer and exporter in North America

R-Control EPS
24000 W. Hwy. 7, Ste. 201
Excelsior, MN 55331
(800) 474-2074
www.r-control.com

R-Control SIPs manufacturers in Texas:
Chapman Building Systems
5275 Highway 27 East
Kerrville, TX 78028
(830) 792-5050
support@sips-chapman.com
www.sips-chapman.com
Full-service panel fabricator, also builds modular homes

Therma Foam LP
2324 Franklin Drive
Forth Worth, TX, USA, 76161
817-624-7204 phone
800-333-3626 toll free
sales@thermafoam.com
www.thermafoam.com
Molder/manufacturer and fabricator

Structall Building Systems
350 Burbank Rd.
Oldsmar, FL 34677
(800) 969-3706
www.structall.com
Full-service panel manufacturer, aluminum and steel skins available, also builds modular homes
San Antonio Service Center:
(800) 880-4198

Transcon Steel of Texas, Inc.
2200 Church Street
Georgetown, TX 78626 USA
512.930.0066
512.680.6560 mobile
gjennings@transconsteel.com
www.transconsteel.com
Light-weight panels with steel skins

Winter Panel Corp.
74 Glen Orne Dr.
Brattleboro, VT 05301
(802) 254-3435
sales@winterpanel.com
www.winterpanel.com
 
General Assistance:

APA-The Engineered Wood Association
7011 South 19th Street
Tacoma, WA 98466
(253) 565-6600
help@apawood.org
www.apawood.org
Resources for engineered wood products

US Department of Energy
Energy Efficiency and Renewable Energy (EERE)
Consumer's Guide
www.eere.energy.gov

Structural Insulated Panel Association
P.O. Box 1699
Gig Harbor, WA 98335
(253) 858-7472
help@sips.org
www.sips.org

ToolBase Services Technology Inventory
www.toolbase.org