SIPs Structural Insulated Panels What is SIP? SIP is an acronym that stands for Structural Insulated Panel. SIPs represent a revolution in building technology. The large, light, easily assembled prefabricated panels make it possible to erect houses and other buildings quickly and with minimal expense. A BRIEF HISTORY Development of “stressed‐skin” panels for buildings began in the 1930s. Engineering and durability testing was conducted at the Forest Products Laboratory (FPL) in Madison, Wisconsin, a facility operated by the U.S. Forest Service. FPL tested the concept of using skins to carry a portion of structural loads by building a small house in 1937.Wall studs in the panels were 3/4” x 2 ½,” rather than the usual 2” x 4”. First Lady Eleanor Roosevelt dedicated the house, and the structure is currently a daycare center run by the University of Wisconsin. FPL scientists reasoned that if skins could take part of the structural loads, maybe they could eliminate framing entirely. Engineering theory was developed and tested, and a complete structure was built in 1947 using corrugated paperboard. This structure was heated, humidified, and exposed to Wisconsin weather for 31 years. The structure was disassembled periodically for testing to observe changes in panel stiffness, and bowing was minimal. In 1969 foam cores were introduced to form the modern structural insulated panel. What is SIP made of ? Typical SIP Structural Insulated Panels (SIPs) The EPS foam core provides shear strength, while the exterior skins of OSB provide tensile and compressive strength. As compared to an I-beam, the panel skins are analogous to the flanges, while the core is its web. The completed panels offer the utmost in R-value, fire resistance, and ease of construction. They are the key structural component in "one-piece" construction, which is significantly stronger than similarly configured stick-built structures. Oriented Strand Board (OSB) First developed in the 1980's, is a wood panel that has been "engineered to perform" for housing and construction. OSB is not chipboard, flakeboard particleboard or aspenite. It has been specifically designed to be the most dependable, versatile, and environmentally efficient wood panel on the market today. OSB uses only freshly harvested trees from sustainable fast growing forests or tree farms. The trees are processed into precise strands averaging 4 inches long and 1 inch wide. The strands are oriented length-wise on the exterior and cross-aligned on the interior. The alternating layers are then bonded with resins under high heat and pressure. The resulting product is very strong and uniform and shares many of the same properties as plywood. Because of its great versatility and performance, we have chosen OSB in all areas of our homes where strength, stiffness, and durability are required. Expanded Polystyrene (EPS) EPS has proven to be the most cost-effective panel core insulation material available. EPS has the highest R-value per dollar invested. Its R-value per inch is much higher than fiberglass or cellulose insulations. "R" means resistance to heat flow. The higher the R-value, the greater the insulating power. EPS is also physically stable, unlike fiberglass or cellulose, which tend to settle with time, creating voids and many thermal breaks. Unlike most insulation products, the R-value of EPS increases as the temperature drops. EPS is an inert, organic, recyclable material. It contains no CFC's, HCFC's, or HFC's, will not rot, is resistant to mildew, and provides no food value to animals (including rodents). New materials in SIPs production OSB is not the only finish surface available for SIPs. Interior and exterior skins can also be varied metals, fiber cement board, plywood or magnesite board (MGB), to name a few. In production of SIPs new and better materials could be used that outperform both OSB and EPS. XPS (Extruded Polystyrene) or PUR (Polyurethane) foam could be used as core instead of EPS. Both of them have better mechanical and insulation properties than EPS. Magnesite boards (MGB) that are water-proof and fire-proof (A1) could be used instead of OSB. SuperSIP is a registered trademark of EUROPANEL ltd. (Tallinn, ESTONIA) What is SuperSIP made of ? XPS (Extruded Polystyrene) Composition XPS is a cell plastic, which is primarily made of polystyrene. Structure XPS excellent characteristics are based on its cell structure. XPS cell structure is completely homogenous and sealed. It differs significantly from the cell structure of EPS. Due to its sealed and uniform cell structure, XPS functions also as vapor barrier. The insulation boards are not subject to water capillarity and they do not need to be separately protected against moisture or freezing temperatures. EPS 100 (18 kg/m3) XPS 300 (32 kg/m3) Magnesite boards (MGB) Composition: Mixture of first grade raw materials i.e.: inorganic substances, natural silicates Si02, CaC03, MgO, MgCI, glassfiber mesh. 100% asbestos free, non-toxic, safe, durable and can withstand fire, water, moisture, insects, vermin, fungi, termite and mildew. Typical applications: MGB is used in a wide range of external and internal general purpose building applications for all type of establishments. Fire resistance: Class A1 Emission : Class M1 Why is SuperSIP super compared to regular SIP ? SuperSIP panels are super compared to regular SIP panels due to the raw materials which are laminated together. Regular SIP panels consist of 3 layers – OSB+EPS+OSB - and are sufficient in normal conditions. However, in severe and demanding conditions, better materials should be used and combined. SuperSIP panels are made in various types and designed according to these needs. Fine insulation materials are polyurethane foams (PU), but they cost more. XPS is superior to EPS and cheaper than PU, but more costly than EPS. In tropical and wet climate OSB is not a good option for sheathing. SuperSIP offers a much better combination here – MGB+XPS+MGB When stronger panels are needed, regular and filmfaced plywood can be used as exterior structural skin material. Also Edge Glued Timber (EGT) panels. To make a special SuperSIP panel that looks finished and is extremely weatherproof, additional exterior sheathing of Aluminum-Composite (ALC) or Fiber Reinforced Plastic (FRP) materials can be used. Calculating the resistance to heat flow in SuperSIP panels Specific heat conductivities: For XPS λXPS = 0,037 W/(mK) For MGB λMGB = 0,139 W/(mK) 170 mm SuperSIP panel (12 mm MGB + 146 mm XPS + 12 mm MGB) RXPS = 0,146 / 0,037 = 3,946 m2K/W RMGB = 2 * 0,012 / 0,139 = 0,173 m2K/W RΣ170 = 3,946 + 0,173 = 4,119 m2K/W K170 = 1/ RΣ170 = 0,243 W/m2K Conforms new Finnish standard for external walls 265 mm SuperSIP panel (12 mm MGB + 241 mm XPS + 12 mm MGB) RXPS = 0,241 / 0,037 = 6,514 m2K/W RMGB = 2 * 0,012 / 0,139 = 0,173 m2K/W RΣ265 = 6,514 + 0,173 = 6,687 m2K/W K265 = 1/ RΣ265 = 0,150 W/m2K Calculating the resistance to heat flow in SuperSIP panels for “Passive house” Specific heat conductivities: For SEPS λXPS = 0,031 W/(mK) Silver EPS For EGT λEGT = 0,14 W/(mK) Edge glued timber (Cross fibre) 342 mm SuperSIP panel (19 mm EGT + 300 mm SEPS + 19 mm EGT) RSEPS = 0,300 / 0,031 = 9,677 m2K/W REGT = 2 * 0,019 / 0,14 = 0,271 m2K/W RΣ342 = 9,677 + 0,271 = 9,948 m2K/W K342 = 1/ RΣ342 = 0,101 W/m2K Conforms min. standards for external walls for so-called “Passive House” 442 mm SuperSIP panel (19 mm EGT + 400 mm SEPS + 19 mm EGT) RSEPS = 0,400 / 0,031 = 12,90 m2K/W REGT = 2 * 0,019 / 0,14 = 0,271 m2K/W RΣ442 = 12,903 + 0,271 = 13,17 m2K/W K442 = 1/ RΣ442 = 0,076 W/m2K Conforms min. standards for ceiling and floor for so-called “Passive House” The advantages of using SIPS are many: Imagine Assembling Your New Home Kit In About 3-4 Days. Even the novice handyman will be able to build the home of their dreams with these affordable and easy to assemble housing packages. These homes are manufactured with Structural Insulated Panels (SIPs), a factory manufactured wall system that replaces standard stick framing and batt insulation with a solid one piece wall section composed of two sheets of oriented strand board (OSB) that has been adhesively welded to a thick rigid core of Expanded Polystyrene Foam Insulation (EPS). • Simplifies Construction: SIPs integrate structure with insulation. The frame of the home and the thermal envelope are one and the same. • Reduced Labor Costs: SIPs can be erected by novice crews and do it yourself builders. Each 4' by 8' panel weighs 125 lbs (some 30 kG/m2), so no crane is usually required for wall panels. Average erection time for exterior wall panels is usually half a day, for a 3-man crew. • Flexibility: There are fewer restrictions to design and more choices to customize from cabin to castle. • Finishes Apply Easily: OSB surface provides a sturdy and continuous nail and screw base to which exterior and interior finishing materials can be attached. • Easily Wired: Pre-cut electrical chases have been built into every panel so that the wiring of the outer walls can be easily done. • Superior Strength: Monolithic shell can withstand seismic forces better than stick built. Our panels are rated 3-5 times stronger than 2´x 6´ (50 mm x 150 mm) construction. SIPs are also tested against tornados and proved to be an excellent building system. SIPs are usable with wind speeds up to 130 mph. • Comfort: Panel homes are quieter and cleaner: The thick solid insulation reduces noise and dust infiltration. • Reduced Energy Use: By virtue of its solid walls and monolithic construction, you are able to eliminate the cracks normally found in the walls of the average stick built home. Heating and air conditioning costs can be reduced by 50%-60% over the life of the home. • Quality: SIPs walls are straight and flat with no bulging framing members. This is virtually impossible to achieve with old-fashioned stick framing. • Safety Much safer in case of an earthquake or a tornado. • Advanced building system Elements are prefabricated, RTA (ready-toassemble). That gives better quality control • Better building environment Cleaner building site, less waste. • Good durability SIPs are usually very resistent to mold and termites. • Environmentally friendly No CFCs, all materials are recyclable. Other Builder´s benefits: * Reduced theft * Lower administrative cost * Faster profit realization * Build year round Other Owner´s benefits: * Can be bought as DIY package of panels – Do it Yourself Kit Saving on foundation. As building made of SIPs are very light, you can save on foundation. Pile or pad foundation are a real alternative. SIP technology gives you an oportunity to get additional space. By replacing a typical exterior wall used in Estonia, 40 cm thick (25 cm light clay construction block +15 cm mineral wool insulation) with 20 cm SIP panel, your exterior wall will be 20 cm less. A 150 m2 house (10 x 15 m) has perimeter of 50 m. On the same size foundation it makes 50 x 0,20 = 10 m2 additional space! SIPs are strong By spreading the structural loads out over large areas, the many individual studs used in stickframing can be eliminated. SIPs structural designs are much stronger than stud walls installed in comparable thickness (even 3-4 times). This strength is similar in principle to the properties of an “I – beam”, in which the strong top and bottom flanges (OSB) are joined by a web (EPS insulation core) A panel acts similar to an I‐beam section. The strength of a panel is determined: • Foam core thickness • Skin tensile strength • Skin compressive strength When a load is applied to the top skin of the panel or I‐beam it goes into compression, the bottom skin goes into tension. Structural Strength of typical SIP (North American) Sheathing – 11,1 mm OSB3 Core – EPS 150 mm thick, 1200 mm wide AXIAL LOAD 64 kN/m when axially loaded 57 kN/m when eccentrically loaded by no more than ¼ of the thickness TRAVERSE LOAD 4 m single span – load at span/333 or 14 mm is 2,33 kN/m2 As SIP works like an I-Beam, traverse loads will increase the more thick the sheathing and the more thick the panel itself. SIP panels are really strong Measures against theft To improve the reliability of outside walls against theft, different measures can be employed: 1. Use different cladding outside • ½ brick wall • Thin ceramic cladding • Metal net + plaster • Wooden cladding • WPC (wood plastic composite) cladding • FRP (fiber reinforced plastic) cladding • ALC (aluminum composite) cladding 2. Use special panels for outside walls, which have metal net inside 3. Use window blinds 4. Always use a reliable alarm system Making a foundation for a SIPs building Due to the fact that SIPs are light-weight, the foundation of such buildings can be downsized and even lighter types of foundations can be used. One option of making a foundation for a SIPs building is to use ICF (Insulated Concrete Forms). These forms are usually made of EPS/XPS By using ICF system when building a foundation you will get: 1) easily assembled planking 2) insulated foundation 3) finished socle House made of SIPs Air leakage in SIP houses More than 50% of a home’s total envelope loss may be due to infiltration! SIPs houses have significantly lower air leakage. The resulting energy efficiency provided generally allows heating and cooling equipment to be downsized, reducing initial capital costs and operating costs. • Low infiltration = shorter duct runs • All ducts inside conditioned space As for the “Passive House”, the air-tightness should be n50 < h-1 according to Blower Door Measurement. Thermal envelope should be well insulated – outside wall U < 0.097 W/m2K, ceiling and floor insulated even better. Energy need for a Passive House is usually less than 15 kWh/m2a Mechanical ventilation is usually a must Due to the typical low air infiltration rate, it is critical that a whole house ventilation system us installed to maintain indoor air quality and control interior humidity levels. We will recommend to install an air-to-air heatpump to recover the heat of the outgoing air. Houses in the future should be built according to the “passive house” concept. How Does Plumbing and Electrical Integrate with SIP Panels? While there are some specific techniques that builders will need to become familiar with, building with SIPs will not create a significant roadblock in your construction. Traditionally, very little plumbing is included in exterior walls regardless of the building style used, and with Structural Insulated Panels (SIPs) most plumbing is located to interior walls. SIPs can be combined with other building elements and systems like: * Engineered joists * Adaptable timber and tube steel framing enveloped with SIPs * Glulam timber beams and frames Simple handtools can be used SIPs application options SIPs can also be used to enclose a structural frame. When SIP wall panels are attached to a structural framework, they are sometimes referred to as “curtain wall” panels. Some buildings incorporate elements of both axial wall bearing load panels and curtain wall panels. These hybride have the efficiency of a structural panel building and they can take advantage of timber framing methods for aesthetic or special load-bearing needs. Structural frame and SIPs An advanced technology of making light hangars (Sweden) Useful literature Building with Structural Insulated Panels (SIPs): Strength and Energy Efficiency Through Structural Panel Construction (For Pros By Pros) [ILLUSTRATED] (Hardcover) by Michael Morley Publisher: Taunton (September 10, 2000) , 192 pages Builder´s Guide to Structural Insulated Panels (SIPs) Joe Lstiburek, Ph.D. More books and information about SIPs can be found here: www.sips.org www.amazon.com www.buildingscience.com www.sipschool.org Connection details according to SIPA Panel connection options I‐Joist Spline • Increases axial and transverse strength • Adds minimal thermal bridging Patent pending innovative frame set, designed by EUROPANEL, is available and ready to be introduced to the market (not described here) Will be produced by some friendly Chinese companies according to agreements. Manufacturing cost already calculated Testing SIPs SIPs as such have been comprehensively tested for mechanical properties, insulation values and fire-resistance in various labs and engineering evaluations are made for construction details. Load charts are also readily available. Due to the light weight of SIPs the dead loads are very small. SIPs and International Codes On May 22, 2007 the International Code Counsil (ICC) voted to incorporate Structural Insulated Panels into the International Residential Code (IRC). The acceptance of SIPs into section R614 of the IRC has been a long anticipated goal of SIPA (Structural Insulated Panel Association) and will undoubtedly bring about significant changes in the SIPs industry. • Builders and design professionals using SIP walls in residential projects will no longer be required to conduct or supply additional engineering to show equivalency to IRC. • Inclusion in the IRC recognizes structural insulated panels as equal to other code approved building systems. 2007 Supplement to the IRC (RB34 – 06/07) Section R614 Applicability limits to SIP constructions - General • • • • • Building Dimensions: Maximum building witdh is 40’ (12,2 m) Maximum building length is 60’ (18,3 m) Number of stories: 2 story (above basement) Basic wind speed: Up to 130 mph (209 km/h) Wind exposures: Exposures B (suburban) Exposures C (open terrain) • Seismic zone: A, B and C • Building height: Maximum 35’ (10,7 m) Applicability limits to SIP floor constructions • • • • Floor dead load 10 psf (0.48 kN/m2) maximum Floor live load First floor 40 psf (1.92 kN/m2) maximum Second floor (sleeping rooms) 30 psf (1.44 kN/m2) maximum Applicability limits to SIP wall constructions • Wall dead load • Load bearing wall height • Deflection Criteria 10 psf (0.48 kN/m2) maximum 10 feet (3 m) maximum L/240 Applicability limits to SIP roof constructions • Roof Dead Load • Roof Snow/Live Load • • • • Ceiling Dead Load Roof Clear Span Roof Slope (Pitch) Rake Overhang 10 psf (0.48 kN/m2) maximum 70 psf (3.35 kN/m2) maximum ground snow load (16 psf (0.77kN/m2) minimum Roof Live Load). 5 psf (0.24 kN/m2) maximum (unsupported) 40 feet (12.2 m) 3:12 to 12:12 2 feet (610 mm) horizontal projection beyond exterior wall Production of SIPs Calculations for minimum needs * Production facility needs to be at least 500 m2. * Two men crew per shift to serve the production line. Additionally a foreman who is also a forklift driver and a storekeeper * The avarage capacity of such production line is ca one 4´x 9´ (1200mm x 2750mm) panel per every 5 minutes. * Some transport and lifting equipment needed, also compressed air. Production line for SIPs 4´ x 18´ (1250mm x 5500mm) maximum To get the best set of equipment and increace the capacity of the production line, some changes should be made to the previous one: * first, to change the vacuum press to a hydraulic one, in which case it would be possible to press a pack of panels at once. * supply/feeding should be half-automated. Production Cost Production line cost starts from ca 300,000 USD Profit margin as high as 100 % Payback time can be as short as 6 months (working in 1 shift) Panels prime production cost (raw materials only) depends on the raw materials used: 120 mm panel = Magnesite board and Expanded polystyrene 12mm MGB + 96mm EPS + 12mm MGB X EUR/m2 120 mm panel = Film faced plywood and Extruded polystyrene 12mm FFP + 96mm XPS + 12mm FFP Y EUR/m2 Additional cost to raw materials (salaries + taxes, amortisation, rent for premises, electricity, heating, etc.): Z EUR/m2 Detailed feasibility study and business plan available on request SIPs in the world The main producers of SIPs today are located in the following countries: USA, Canada, UK, Australia, Japan North-American producers and SIPs system builders have united into an association Today´s market in USA Marketing and Sales Sales can be devided into sales of: • Standard panels • Sets of panels as by DIY principle • Assembled walls with doors and windows • Together with architects and building companies house packages • Technology, know-how and franchise Marketing plan includes use different media: Internet, TV, Books, Training and presentations, Fairs and exhibitions, direct marketing, etc. Marketing and sales plan available on request. After testing and certification according to ETA (European Technical Approval) panels can be sold all over EU. Sales in countries in Asia, Africa and South America, which are not so wealthy, but where there is a hugh need for affordable houses. They usually have state-controlled and guaranteed national housing programms, backed up by local banks. Different types of panels can be used in different climate. Sales of DIY sets in differnt countries all over the world. These sets need minimum skill and only some simple hand tools to erect and are especially suitable for smaller buildings in the countryside – like garages, shelters, workshops and storages. Photos from building sites Buildings made of SIPs You better believe it! SIPs building in Arctic region Panel connection detail drawings Thank You!