A Brief History of SIPs
What are SIPs?
Structural Insulated Panels Panelized Building System High Energy Efficiency High Strength Fast and Simple Construction High Quality
Conventional SIPs
Developed over 50 years ago. Typically composed of expanded polystyrene (EPS) foam insulation sandwiched between two layers of plywood or OSB.
Used extensively in Europe and the Northeastern US, Alaska and Canada SIPs are particularly effective in extreme thermal climate zones such as high mountain, snow country and deserts. The high insulatiing value and minimal thermal bridging make them very energy efficient. Manufactured to exacting standards under controlled conditions. Even conventional SIPs have also withstood severe structural loading conditions such as earthquakes and hurricanes.
A Brief History of SIPs
• • • • • • • • • • • • 1935- The Forest Products Lab (FPL) builds the first in a series of experimental SIP houses in Madison, WI. 1947- FPL builds the Experimental Sandwich building, which is tested and monitored for 31 years. The structure is still in use today. 1952- Alden P. Dow builds SIP homes in Midland, MI. 1958- NAHB builds demonstration research homes with SIPs. 1959- Koppers Corp. starts SIP plant in Detroit. 1962- APA Lab Report # 193 on Sandwich Panels published. 1967- APA Lab Report # 193 first appears in the Model Building Code- UBC. 1969- APA Supplement Four on Sandwich Panels is released. 1970USDA Forest Service Research Paper FPL 144, Longtime Performance of Sandwich Panels in Forest Product Laboratory Experimental Unit, is published. 1973- Oil embargo- fuel prices soar. 1981- Oriented Strand Board (OSB) manufacturing begins. 1990- Group of SIP manufacturers form the Foam Core Panel Association (name later changed to Structural Insulated Panel Association). 1991- SIP market study published. Spotted owl habitat threat reduces old growth timber availability. 1994- SIPA Strategic Long Range Plan developed. OSB oversupply brings OSB prices down. 1995- 1997- Industry production increases by 50% per year. Current estimates are that SIPs will account for 1 1/2% to 2% of the total residential market for 1997. Estimates run from 2% to 3% for 1998. Industry goals are for around 10% by 2001.
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Types of Insulation used in SIPs
• Molded Expanded Polystyrene (MEPS) Foam Board Polystyrene pellets are mixed with various chemicals to liquefy them. A blowing agent is then injected into the mixture, forming gas bubbles, which produce a closed-cell material that are then molded into large sheets. Commonly known as beadboard, it has an R-value of about 4 per inch of thickness. Extruded Expanded Polystyrene (XEPS) Foam Board Extruded expanded polystyrene insulation is similar to MEPS, but the foaming, thick liquid is forced through a shaping die. Polyurethane and Polyisocyanurate Polyurethane and polyisocyanurate are both closed-cell foams that contain a low-conductivity gas in the cells (usually one of the HCFC or CFC gases.) These heat-resistive gases provide higher R-Vales of around R-7 to R-8 per inch.
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Advantages of Using SIPs
• • Energy Savings - Typical savings of 35-50% on HVAC vs. conventional stick framing systems. Environmentally Responsible - Reduce reliance on wood-based products.
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Speed of Construction - Reduced labor costs; contractors can do more jobs over the same amount of time – Typically shortens envelope construction timetable by 50% or more.
High Quality – Precision manufacturing results in tighter tolerances, better quality. Increased Strength - SIPs offer increased strength over stick or other wood construction. Reduced Management - With SIPs, the frame of the building and the thermal envelope are one and the same, which simplifies the supervision and coordination of the various aspects of construction. Pre-cut electrical & mechanical chases simplify plumbing and electrical tasks. Increased Building Season – Quick erection of building envelope lengthens the building season in many parts of the country.
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Reduce or Eliminate Job Site Waste. High-performance building envelopes help builders qualify for and obtain EnergyStar and LEEDs points and requirements.
Advantages of SIPs
• Quieter Structure – EPS sound attenuation qualities reduce noise pollution.
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Design Flexibility - SIPs can simplify construction by integrating structure with insulation. Panels can be used for walls, roofs, and floors, window and door openings are already in place, headers are pre-engineered and installed. Versatility – Many types of SIPs can be used as either load-bearing or “skin” applications, allowing use in a wide range of construction projects.
Economical – Most types of SIPs compare very well on a materials cost basis with other types of construction. The real savings comes from reduced installation costs and energy cost savings over time.
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Reduced HVAC Requirements – Often enables use of smaller units.
Lumber Quality
• A major reason for expanded interest in SIPs is the poor quality of lumber available for residential construction in the U.S. today. Most framing lumber is green, typically with a moisture content of about 19%, and quite often has other defects such as excessive knots, warping, mold, etc. Use of this poor quality material for the primary structure of a building can result in many serious problems.
– – – uneven walls and ceiling nail or screw “pops” in drywall toxic mold
Light – Gauge Steel Framing
• • Cold-formed steel members are used for studs, joists, rafters and headers. Steel mills produce galvanized sheet steel, the base material for steel members. This steel is roll-formed into shapes used for framing. It is zinc coated (galvanized) to prevent corrosion. Many shapes are available, but the primary shapes are the C-shape stud and the U-shaped track. Framing members are generally produced in thickness of 12 to 24 gauges with 3-1/2” to 12” widths. Manufacture of steel framing members adheres to strict tolerances, which results in consistent strength, straightness, and dimensionally stable members. Steel framing provides excellent design flexibility due to the inherent strength of steel, which allows it to span longer than wood, and also resist wind and earthquake loads. LG steel framing has been used for many years in the commercial arena and is a well-proven construction method. Only recently has steel become more common in residential construction.
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Light – Gauge Steel Framing Advantages
• • Superior Strength – Highest strength to weight ratio of any conventional building material. Flexibility -- The variety of sizes and thicknesses of steel contribute to flexibility. For example, to obtain a desired design you can reduce the width of a joist but compensate with a heavier gauge steel and not change the spacing of members. Durability – Steel will not shrink or warp, resulting in fewer call-backs for nail pops or split seams in gypsum board. Also, steel is inorganic and therefore, it is resistant to mold, insect or rodent infestation and will not rot, warp, split, crack or creep. Dimensional Stability-- Since steel is a processed material rather than organic, it is straight, uniform and consistent in quality.
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Fire Resistant– Steel is non-combustible. It does not burn or contribute fuel to the spread of a fire, and may contribute to lower insurance rates.
Advanced SIP Systems
SIPs have evolved considerably over the years, and now include a wide variety of materials and designs.
HY-R Building Systems
HY-R Building Systems incorporate all the advantages of SIPs and light-gauge steel framing in one product.
HY-R framing method is conventional steel framing encapsulated in EPS foam insulation, which eliminates thermal bridging problem associated with steel members. HY-R’s design and engineering departments ensure that architects, designers and engineers don’t need to change anything on their end. We convert standard drawings to panelized versions and certify engineering of our systems. HY-R systems are designed to meet or exceed code requirements for any area. HY-R systems usually do not require any specific testing certifications, as both the framing and insulating technologies are already covered under IBC. HY-R provides an on-site, factory-trained technician on each job to train installation crews and to ensure our products are erected properly and in conformance to codes.
Superior customer service and support results in on-time, onbudget projects every time.