Key Components of a Grade I Installation

While it is commonly known that buildingÌýinsulation is a criticalÌýcomponentÌýto achieveing optimal energy efficiency in homes and buildings,Ìýmany people don’t realizeÌýthatÌýtheÌýinsulationÌýinstallation is almost as important as the insulation itself.ÌýPoor installation practices can lead to a host ofÌýperformanceÌýproblems,Ìýranging from not meetingÌýenergy efficiencyÌýrequirements to creating theÌýpotentialÌýforÌývapor drive that leads to condensation.ÌýBeyond that, there is an international push to drastically improve energy efficiency in our homes and buildings, and this push reliesÌýonÌýcorrectly installedÌýinsulation as one of the critical lynchpins toÌýsuccess.ÌýÌý

As a result, the industry has developed a standard grading method forÌýinsulationÌýinstallation practices, with GradeÌýIÌýInstallations being the best and GradeÌýIIIÌýInstallations being the worst.ÌýIn many cases, anything less than a GradeÌýIÌýinstallation will not be sufficient to meet energy efficiency requirements set by Energy Star, DOE Zero Energy Ready Homes, utility incentive programs, and Home Energy Rating System (HERS) index.ÌýAdditionally, anything less than a GradeÌýIÌýinstallation wastes moneyÌýfor the contractor and the building owner.ÌýÌý

With that in mind, it’s important to understand exactly what differentiates a GradeÌýIÌýinstallation from the other grades, and what installers, inspectors, and homeowners should know about meeting GradeÌýIÌýinstallations.ÌýÌý

TheÌýinstallationÌýgrading system is set by RESNET,Ìýthe Residential Energy Services Network. The score depends on how well the installation meets the insulation manufacturer’s installation instructions. It also covers all types of insulation, includingÌýfiberglass,Ìýspray polyurethane foam (spray foam) ,Ìýmineral wool,Ìýand cellulose.ÌýÌý

A Grade I installation requiresÌýthe material to uniformly fill each cavity completely, from side to side and top to bottom. There cannot beÌýany gaps or voids around obstructions (such as blocking or bridging)ÌýorÌýaround wiring and other services in the cavity. This type of installation will not only improve energy efficiency, butÌýitÌýwillÌýalso prevent callbacks for the contractorÌýandÌýcode officials. A Grade I insulation calculates that 100% of the area to be insulated has been filled.ÌýBear in mind, that in some casesÌýand depending on the type of insulation being used, the area to be insulated may not include the entire depth of the wall cavity, though it would still include allÌýfourÌýsidesÌýandÌýthe top and bottom.ÌýÌý

For example, if the application requires an R-13, installers could achieve this R-value with 2 inches of closed-cell JMÌýCorbond®ÌýIII or JMÌýCorbond®ÌýIV spray foam. Installers would need toÌýensure thatÌýthe cavity was uniformly filled onÌýall sides with 2 inches of insulation; however, they would not need to fill the entire depth of the cavity (3.5 inches) with insulationÌýto achieve theÌýrequiredÌý
R-value.ÌýÌý

The pictures above show a Grade I installation with fiberglass (left) and spray foam (right).
The pictures above show a Grade I installation with fiberglass (left) and spray foam (right).

The second-best type of installation is a Grade II installation. In Grade II installations, there is some allowance for imperfections, such as gaps around intrusions or an incomplete fill. A Grade II installation identifies that 98% of the area to be insulated has been filled to the required R-value and that 2% of the area remains uninsulated.

Grade III installations are the lowest grade, and they are described as having “substantial gaps and voids.â€� In this type of installation, 95% of the area to be insulated is considered filled, while 5% of the area remains uninsulated. This does not mean that the installation delivers 95% of the intended R-value, but rather that only 95% of the area that should be insulated has been insulated. The remaining 5% of the area may have some insulation or no insulation at all, but it has not been sufficiently insulated to the proper R-value.Ìý

The pictures above show a Grade III installation with fiberglass (left) and spray foam (right).
The pictures above show a Grade III installation with fiberglass (left) and spray foam (right).

The visual difference between a Grade I installation and a Grade III installation is apparent, and inspectors who view installations on a daily basis will easily be able to identify one from the other. Learning to deliver a Grade I installation doesn’t benefit just the building owner by ensuring optimized energy efficiency; it also saves the contractor money by ensuring that they won’t be called back to do rework.

That said, it is clear that a Grade I installation requires more technical know-how and a greater emphasis on quality control. If you would like to learn more about how to deliver a Grade I installation, visit , or you can contact JM’s TechConnectSM TeamÌýto speak with someone directly.Ìý