Frequently Asked Questions

What are SIPs?

Structural insulated panels (SIPs) are high performance building panels used in walls, roofs and floors for residential and light commercial buildings. The panels are made by sandwiching a core of rigid foam insulation between two structural OSB facings’.

SIPs are manufactured under factory controlled conditions and can be custom designed for each project.

The result is a building system that is extremely strong, energy-efficient and cost effective.

Building with SIPs will save you time, money and labor

How much faster can I build with SIPs?

SIP homes go up much faster than traditionally framed buildings. A properly trained SIP installation crew can cut framing time by 55 percent compared to conventional wood framing, according to a third-party study conducted by R.S. Means. Panels are manufactured as big as 8- by 24-foot, so entire wall and roof sections can be put up quickly, reducing dry-in time. SIPs are ready to install when they arrive at the jobsite, eliminating the time needed to perform the individual jobsite operations of framing, insulating and sheathing stick-framed walls. Electrical chases are typically provided in the core of panels, so there is no need to drill through studs for wiring

How much money can I save with 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.

How Strong are SIPs?

The structural characteristics of SIPs are similar to that of a steel I-beam. The OSB facers act as the flange of the I-beam, while the rigid foam core provides the web. This design gives SIPs an advantage when handling in-plane compressive loads. SIPs are used for high wind designs in excess of 180 mph and are approved for Florida’s strict High Velocity Hurricane Zones (HVHZ). The load-bearing area of SIPs is equivalent to building with 2 x 10 framing at 16 inches on center.

How do I size HVAC ?

A high-performance SIP building enclosure often allows smaller HVAC equipment to be specified. It is important to work with a qualified HVAC professional that can accurately estimate the low levels of air infiltration in a SIP home or commercial building. Proper HVAC sizing is crucial because an oversized HVAC system will fail to reach the steady operating rate the equipment was designed for. Short cycling HVAC equipment will be less energy efficient and require more maintenance than properly sized HVAC equipment.

How important is ventilation?

SIP buildings are extremely airtight with air leakage rates well less than 3 air changes per hour at 50 Pascals of pressure (3.0 ACH50) and require mechanical ventilation. Ventilation systems bring fresh air into the building in controlled amounts and exhaust moisture laden and stale air to the outside. By limiting air exchange to controlled ventilation systems, SIP homes allow for all incoming air to be filtered for allergens and dehumidified, creating better indoor air quality. Proper ventilation is important in all homes to preserve indoor air quality.

How do SIPs improve indoor air quality?

The airtightness 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

How do SIPs react to a fire?

Like all wood frame buildings, SIPs present a manageable fire risk when their construction meets the fire precautions listed in the building code. Residential codes typically require the application of a 15-minute fire-resistant thermal barrier on the interior for all residential structures, accomplished by applying 1/2-inch-thick gypsum board or a material of equivalent thermal performance. Light commercial or multi-use buildings of Type V Fire Rated construction often require a one-hour fire rating and/or sprinkler systems.

How are Electrical wiring and fixtures installed?

Electrical wires are pulled through pre-cut channels inside the core of the panels called “chases.” Chases are added during the manufacturing process according to the electrical design of the home. Electricians can feed wires through panel chases without compressing the insulation or drilling through studs

Does a SIP building roof need to be ventilated?

The area inside a SIP building envelope is considered conditioned space and will be ventilated by the building’s HVAC system. There is no need to provide a vented attic beneath a SIP roof, and doing so would compromise the conditioned space of the building. Some building science experts recommend venting the roof by providing an air space between the SIP roof panels and the roofing material (known as a “cold roof”). Although this best practice is not a requirement for SIP buildings, it is a sensible extra measure to improve the durability and moisture resistance of the building.

Do roofing manufacturers warranty asphalt shingles?

Some roofing manufacturers warranty asphalt shingles over unvented SIP roofs, while others void their warranty because of higher shingle temperatures. Research conducted by Building Science Corporation reveals that although asphalt shingle temperatures increase slightly (2 – 3 degrees F) in an unvented roof assembly, the color of the shingles and the roof orientation have a much more profound impact on the durability of shingles. According to the Builder’s Guide to Structural Insulated Panels (SIPs) published by Building Science Corporation, the typical reduction of shingle life over an unvented SIP roof assembly is between one and two years. Builders seeking to comply with roofing manufacturer warranties can choose from a variety of more durable, non-asphalt roofing materials or provide a venting space between the SIP roof panels and the roofing material (known as a cold or ventilated roof).

Are SIPs code approved?

SIP construction is recognized by the International Code Council body of building codes, which are used by most jurisdictions in the U.S. SIPs are also approved by the State of Florida for High Velocity Hurricane Zones (HVHZ). For residential buildings, specific construction practices for SIP wall systems are included in Section R610 of the 2018 International Residential Code. For applications beyond the scope of Section R610, the building inspector will typically require a licensed engineer or architect to approve the building plans prior to construction. An engineer’s approval is always required in high wind areas, high seismic zones and commercial building

How are SIPs supported, are there studs in the panels?

For most applications, SIPs are structurally self-sufficient. The structural characteristics of SIPs are similar to that of a steel I-beam. The OSB facers act as the flange of the I-beam, while the rigid foam core provides the web. This design is extremely strong and eliminates the need for additional framing. In cases where a point load from a beam or header requires additional support, a double dimensional lumber spline or engineered wood spline is field-installed at in-plane panel connections. SIPs are also used as curtain walls for steel frame or timber frame structures. In large commercial applications SIPs can minimize the amount of structural support needed and reduce material costs. In roof applications, SIPs rely on beams and purlins for support. SIPs can span long distances, allowing a minimal amount of structural supports to be used. Embedding I-joists into the SIP roofs can also easily increase roof spans and loads