Structural Insulated Panels (SIPS) are an Advanced method of Framing and SIP Structures lead the way in Energy Efficiency.
SIPs consist of an inner core of Expanded Polystyrene (EPS) which has been laminated between two sheets of Oriented Strand Board (OSB) using a Structural Adhesive. This Engineered System provides an extremely strong building panel that does not require any additional framing for support. Large Pre-Fabricated SIP panels make the framing process much faster than any other framing method and enables a more airtight, well insulated building for high Energy Efficiency.
SIPs are available in a variety of thicknesses and sizes ranging from 2 to 12 inches thick and in sizes from the standard 4 x 8 to 8 x 24 feet. Panels generally weigh less than 4 pounds per square foot, making them light enough to install by hand. A crane often is used for larger roof panels or for lifting bundles of panels on the job site.
Once the SIPs are installed, you can apply virtually any finish to polish off the exterior — Stucco, Stone, Hardie Plank, Brick or Clapboard
A well-built home using SIPs will have a tighter Building Envelope and the walls will have higher Insulating Properties, which leads to fewer drafts and a decrease in operating costs. Also, due to the standardized and all-in-one nature of SIPs, construction time can be less than for a frame home, as well as requiring fewer tradesmen. The panels can be used as floor, wall, and roof. As a result, the total life-cycle cost of a SIP-constructed building will, in general, be lower than for a conventional framed one—by as much as 40%. The total construction cost (materials and labor) is often lower than for conventional framing appears to depend on the circumstances, including local labor conditions and the degree to which the building design is optimized for one or the other technology.
An OSB skinned system structurally outperforms conventional stick framed construction in some cases; primarily in axial load strength. SIPs maintain similar versatility to stick framed houses when incorporating custom designs. Also, since SIPs work as framing, insulation, and exterior sheathing, and come precut from the factory for the specific job, the exterior building envelope can be built quickly and efficiently.
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A FEW THINGS TO KNOW ABOUT SIPS
SIPs are growing in popularity for all types of homes, but especially structures that are aiming for maximum efficiency and sustainability. Here’s why.
They go up Quickly and Easily. Depending upon the size and design of a home, it can be enclosed with SIPs within days or even hours. This saves money on labor, insurance and financing, as well as energy on the job site.
They’re Flexible. SIPs can arrive at the home site and the panels will be cut exactly to the home’s design at our factory, then numbered for easy installation, which results in less wasted materials and resources.
They’re Energy Efficient. SIPs cut heating and cooling costs by as much as 60 percent over products used for conventional “stick” construction. Even where wall thickness is the same, SIPs outperform stick framing on whole-wall energy performance by 40 to 60 percent, according to a study by Oak Ridge National Laboratory.
They’re Soundproof. SIPs block sound like few other materials—a big perk, especially in bedrooms, dens, home offices and media rooms. This due to the solid construction and lack of air transfer,
They’re Environmentally Friendly. Components that comprise SIPs come from renewable resources. The insulation is a form of plastic, and oriented strand board (OSB) is made from fast-growing trees and shrubs once considered waste by the lumber industry.
WHEN ARE SIPS USED
A key component of the upcoming comprehensive new building code requirements for residential construction is more stringent requirements for energy efficiency in walls and ceilings, and by enclosing your home with SIPs, it’s an easy way to meet those requirements. Plus, SIPs combine a firm wall, exterior sheathing and hearty insulation into one step, making the installation quick and easy.
SIPs are used when:
- a high performance, energy efficient, framing solution is required.
- you want a quick lock up time
- you are in a remote location and a panelized system makes more sense (less transportation of construction materials and waste)
- transportation to the site is limited
WHERE ARE SIPS USED
Typically, the Exterior Envelope is where SIPs are used. Insulated Floors, Walls and Roof.
“Reducing heating and cooling costs plays a major role in construction of any type of building……..thats where SIPs come into play. SIPs create a much tighter building envelope than is possible using other construction methods.
The rigid foam core inside each SIP provides continuous insulation across the panels’ width and length, avoiding the thermal bridging created by wall studs. Also, because SIPs come prefabricated in large sizes (up to 8 by 24 feet), SIPs have significantly fewer joints that require sealing.
Blower door tests find that rooms built with SIPs have significantly less air leakage than stick-framed spaces. Whole-wall R-values of SIP Walls versus stick framed walls are much higher when taking into account energy loss through the structural members, corners, joints, and around windows.
In many applications, SIPs are structurally self-sufficient and do not require additional structural framing. The oriented strand board (OSB) skins and foam core work together as an engineered system with high load-bearing capacity, including axial, transverse, racking, and diaphragm capacities. As such, they can accommodate a wide range of loads, including those from gravity, snow, high winds, and seismic activity.
Compared to stick framing, SIP walls go up much faster since they can be installed in large sections and eliminate the need for separate on-site framing and insulation work.
Other ways SIPs help speed construction is that they come to the jobsite with pre-cut window and door openings, which saves on framing time, and depending on the dimensions, may not require installation of separate headers. They also have pre-cut electrical chases that eliminate the labor needed to drill through studs for wiring.
Because SIPs are comprised of full oriented strand board (OSB) panels, they provide a solid surface across each wall’s entire face, unlike drywall over studs. SIPs stand up well to the bumps and damage that can occur . SIPs are strong, You can’t damage them as easily as conventional framing.
Testing has been completed for SIPs in accordance with ASTM E 72 for transverse load capacity and deflection monitoring. WEST-ECO can provide details on specific load capacities for roof applications with their specific SIPs.
One primary benefit of SIPs in roofs is their long clear-span capability. The large, single-piece panels can typically span up to 20 feet, reducing the need for interior columns or other intermediate structural supports. Design professionals also can use SIPs in roof structures without an engineered truss system. These capabilities work well for vaulted ceilings, large open spaces, and soaring rooflines, which are common in schools, lodging facilities, multi-housing, and other institutional and commercial building designs.
SIPs also work well in cantilevered roof eaves and gable-end overhangs extending up to 6 feet. The monolithic panels can help speed construction of such design features, compared to framing with individual components.
One application that has been growing in recent years is incorporating SIPs as part of living roofs. Because SIPs can accommodate high loads from soil, plants, and water, and have fewer gaps than other roof-framing methods, SIPs can help meet the challenges of a green roof.
Structural Insulated Panels
Although less common than wall and roof applications, designers can also use SIPs in floor structures where they are not supporting load-bearing walls. Additional support below any load bearing wall is required. SIPs are most commonly used where an insulated floor system is required, such as when building on piers or pilings or other unheated areas.
Follow the future of framing like so many other homeowners have! For more than 50 years, SIP roofs, walls and floors have framed homes from the ocean front in Western Canada, to hot temps in Southern Florida, to freezing winters from Alaska to the Yukon.
Decades in the field have shown that SIP homes have stood stronger, straighter and greener than those homes framed with traditional 2×6 lumber and batt insulation.
THE COST OF SIPS
Builders can save money through decreased construction and labor costs. A high performance building envelope often allows HVAC equipment to be downsized and ductwork to be minimized. Builders can also significantly reduce jobsite waste disposal and temporary heat during construction. Homeowners that incorporate other energy-efficient features into a SIP home can see utility savings of 50 percent or more.
FACT: Material costs of SIPs over 2×6 stick framed lumber construction is 0-20% higher (depending on region). ENVELOPE ONLY
FACT: Material costs of SIPs may cost no more than conventional stick framing… IF… the stick framed envelope is build to compare to the same efficiencies as SIPs provide.
FACT: Overall project costs of SIPS over 2×6 stick framed lumber CONSTRUCTION is up to 30% less!
BREAKING IT DOWN
A proven higher efficiency product (SIPs) may cost more, but they help the overall project cost less in most cases. A superior project for the same or less total project cost? WHY NOT?
OVERALL SIPS PROJECT COSTS
How does a building cost less to build if SIPs can cost slightly higher than traditional stick frame?
- Pre-insulated! No need to purchase additional insulation
- Pre-fabricated & precut when delivered to the jobsite: save 20-30% on framing labor
- Electrical is installed 20-30% faster
- Jobsite waste reduced with pre-cut panels — saves approximately 30% on waste sent to the landfills
- Tighter house means smaller HVAC systems — up to 40% savings
- Predictable STRAIGHT engineered product is plumb & square every time = faster install for finish work. Doors/windows/millwork: no bowed lumber = straight walls for faster doors/window/millwork install.
- Floors: level floors and walls = no need to shim
- House is dried in faster, subs can start sooner — fewer wasted “crew” days
- No roof venting required in low slope roofing
- Better indoor air quality, smaller or no air purification systems required in many climates
- Buildings & houses are FINISHED faster. Less interest paid.
With all of these project factors considered SIPs are regularly less expensive than 2×6 framed construction:
|BENEFIT||2×6 R20 CONSTRUCTION||SIPS CONSTRUCTION|
|Energy Efficiency||CODE Required||Up to 48% more efficient|
|R Value||The Department of Energy’s Oak Ridge National Laboratory has studied and tested the performance of entire wall assemblies in large sections. The resulting whole-wall R-value data reveals that a 4.5″ SIP wall rated at R-14 outperformed a 2″x6″ wall with R-20 fiberglass insulation.||Premier SIPs have a 20 year R-Value warranty:
4″ wall 15.0 – 16.0 R-Value
6″ wall 23.0 – 24.0 R-Value
8″ wall 30.0 – 31.0 R-Value
10″ wall 38.0 – 39.0 R-Value
12″ wall 46.0 – 47.0 R-Value
|Strength||Baseline||20-30% Stronger – The structural characteristics of SIPs are similar to that of a steel I-Beam. The OSB skins act as the flange of the I-beam, while the rigid foam core provides the web. This design gives SIPs an advantage at handling in plane compressive loads.|
|Waste Created||Baseline||30% less salvageable structural lumber sent to landfills over stick. SIPS are recyclable and made with a significant amount of recycled content.|
|Labor Costs||Baseline||Up to 55% labor savings. Proven! Read SIPA News Release|
|IAQ – Indoor Air Quality||Baseline||The tightness of the SIP building envelope prevents air from gaining access to the interior of the home except in controlled amounts. A controlled indoor environment is both healthy and comfortable. Humidity can be controlled more easily in a SIP home resulting in a home that is more comfortable for occupants and less prone to mold growth and dust mites.|
Benefits of SIPS
- Structurally Superior: Compared to non-engineered 2×6 lumber.
- Faster construction time: SIP panels come precut from the factory per your custom plans. Much like a jig saw puzzle, SIPs are installed in days rather than weeks. Therefore, a SIP house can be dried in and ready for siding/roofing much faster than traditional 2×6 framed construction with batt insulation.
- Dramatically reduced air transfer through exterior walls
- Less jobsite waste
- Fewer trades to coordinate
- Airtight exterior walls
- Warmer in winter; cooler in summer
- Very low thermal bridging
- Sound Investment: Appraisers now recognize advanced building materials and sustainable features in home values.
- Strong Warranty Offers Peace of Mind (you won’t see this with stick framed lumber).
- Reduced Heating/Cooling Costs: Up to 60% less!
- Better for the Environment: Less energy used, reduces green house gas emissions.
- Healthier Home Environments: Large panels with far fewer joints than stick framed construction mean fewer pollutants are able to enter the walls.
- Indoor Air Quality (IAQ): Tighter and better insulated structures enable the occupants to regulate the air quality with simple ventilation techniques. The EPA also recognizes SIPs role in providing healthier IAQ and outlines some of the reasons why proper ventilation is critical to home occupant’s health here.
THE SCIENCE BEHIND SIPS
Before you start comparing numbers, you need to determine the true energy efficiency of your building envelope. A building’s energy efficiency is more than just an insulation’s tested R-value.The whole-wall R-value is a more accurate measurement of real-world performance compared to the insulation’s R-value alone. Many studies show a building’s airtightness has more of an impact on energy efficiency than the R-value of the materials themselves. In fact, air leakage is responsible for 40% of heat/cooling loss (wasted energy).
Airtightness in SIPs vs Stick Framed Construction In a study by the Department of Energy’s Oak Ridge National Laboratory, two identical test rooms were built side by side. One stick-framed, one SIP-framed. Rooms were tested for air infiltration and the SIP room was FIFTEEN times more airtight, and more energy efficient than the stick-framed room. This alone illustrates how critical airtightness is to a building’s energy efficiency. The science behind air infiltration in framing products explains the key types of air movements and their effect on energy efficiency.
Air leaks through joints in the sheathing and the inevitable gaps between lumber connections and between wood framing and the insulation. SIPs dramatically reduce air transfer within walls and roofs by minimizing these joints and by providing solid, continuous insulation across each panel’s height, width and depth.
SIPs can be manufactured up to 8’x24′ without joints in the OSB, whereas typical stick-frame sheathing is typically only 4′ wide. Air can also leak through electrical and plumbing holes that are drilled in lumber studs.
The airtightness of a SIPs home has been repeatedly confirmed with
blower door tests.
As warm air rises and cold air sinks in a conventionally framed wall cavity, a natural phenomenon called thermal or convective looping occurs, wasting valuable energy. Unless the insulation is a solid material to stop this air movement, it doesn’t matter what the insulation’s R-value is. What good is insulation if heat-carrying air can flow thought it and the cavities in the wall? SIPs solid insulation core helps eliminate this.
Thermal bridging occurs where there is a continuous element (such as studs within traditionally framed walls, and studs within traditionally framed walls, and stud-to-siding connections) between the cold and warm faces of a wall. These wood elements form a bridge between the inside and outside that can allow heat or cold to pass through by conduction. Simply installing R-19 batt insulation in a stick wall doesn’t mean the whole wall will have a R-19 R-value because there is still a significant amount of thermal bridging in traditionally framed stick walls.
Stick-framed buildings rely on lumber at regular intervals to provide structural support. 15-25% of the shell of a stick-framed home is lumber, compared to as little as 3% in the shell of a typical SIP framed home.
Whole Wall R-value (Energy Efficiency)
When all of these factors are considered, it makes sense that the ORNL’s whole wall R-value tests showed the following R-values for SIP versus stick-framed buildings:
|2×6 stick wall with R-20 fiberglass and studs at 24″ o.c.||R-13.7|
|2×4 stick wall with R-12 fiberglass and studs at 16″ o.c.||R-9.6|
SIP maintained their stated R-value in whole wall testing:
|Core Thickness||SIPs R-Value @ 24 degrees Celsius||SIPs R-Value @ 4 degrees Celsius||SIPs R-Value @ -4 degrees Celsius|