Figuring out code requirements and picking the right insulation system for your building can be confusing. Our Rmax representatives can review your design and help select a system that will meet or exceed your energy codes and standards.
Typical insulation materials like fiberglass batts and mineral wool offer effective thermal resistance, ease of installation, and compatibility with various roof and attic designs. They also offer a wide range of R-values to choose from.
How Building Codes Affect Insulation
When building a new home, commercial structure or adding an extension to an existing building, builders must adhere to local and state construction laws. These laws are typically based on model codes developed in national processes that incorporate input from multiple stakeholders. These codes are designed to ensure that buildings protect people and their property from fires, earthquakes and extreme weather. They also ensure structural integrity, electrical and plumbing safety and accessibility. And they establish energy efficiency requirements, requiring builders to insulate buildings adequately for their climate zone.
These energy code requirements often change over time, depending on the revisions to the model code that dictates them. The most recent version of the International Energy Conservation Code, for example, requires continuous insulation in most climate zones. The requirements differ by zone, so builders must refer to a specific table to determine the R-values required for their project.
Keeping up with these updates is essential to help U.S. manufacturers compete globally. If we let our codes get too old, it will be hard for U.S. suppliers to keep up with European building component makers, who will be using advanced products and practices that were on the cutting edge of innovation just a few years ago.
Insurance companies are another major driving force for updated building codes. They’ve found that buildings built to current standards save them a significant amount of money in loss mitigation costs compared with those built to outdated standards.
What Insulation Materials Are Required by Codes?
Insulation plays an important role in a building’s envelope, providing comfort and optimized energy performance. It minimizes air leakage, keeps moisture and pollutants out of occupied spaces, and helps regulate indoor temperature to reduce condensation and mold growth. The vapor barrier properties of insulation can also help minimize the spread of fire and impede smoke during a fire.
When choosing insulation, it’s best to use materials that meet local code requirements. The New York State Department of State Division of Building Standards and Codes provides a helpful guide that breaks down New York’s requirements by climate zone. The guidelines are based on the 2018 edition of the International Energy Conservation Code (IECC).
In the case of a residential construction project, R-values are determined by the code, and the minimum R-values for walls vary depending on the climate zone in which the building is located. The maximum wall thickness in each climate zone is based on the R-value, and any framing members such as studs must be insulated to the same thickness as the studs in order to reach the required R-value.
Other important considerations include insulation type and certification. Certain types of insulation, such as Rmax polyiso, are certified for use in metal buildings, meaning that they’re manufactured with a foil face during production that creates a built-in vapor barrier to minimize the transfer of water vapor that would reduce insulation effectiveness. This eliminates the need for additional costly vapor barriers to be installed separately, making it easier to achieve compliance with building codes.
What Types of Insulation Are Required by Codes?
Insulation materials are available in a variety of forms, thicknesses and R-values. Many insulation products must meet fire safety, environmental and thermal performance standards. The type of insulation used depends on the project and climate.
Fiberglass, fiberglass batts and mineral wool are flexible and cost-effective building insulation materials. Foam board insulation is denser and more costly than fiberglass, but offers higher R-values and stronger resistance against moisture.
Cellulose and spray foam insulation are versatile and specialized insulation options. They are installed in tight spaces and around openings, and can be shaped to fit into corners. They are often sprayed in place or “foamed-in-place.”
Loose-fill and blown-in-place insulation is designed to be installed between wood-frame walls, joists or beams. It is a great choice if framing is irregular or for filling gaps. It is also good if a space must be kept closed to prevent the spread of fire or contaminants.
Concrete block walls are insulated either as part of the wall assembly or separately. Insulated blocks are sometimes stacked without mortar (dry-stacked) and surface bonded or backed by 1/2-inch gypsum board for fire safety. They are a great choice for moderate climates, and provide high R-value with very little thickness.
What Types of Insulation Are Not Required by Codes?
New construction homes can reduce energy costs and air leaks by using a combination of cavity insulation and insulative sheathing products. When used in conjunction with each other, these systems can save a home owner money and make the structure safer and more comfortable than traditional wood framing methods. The sheathing and insulated insulation can also provide additional support for exterior walls that are exposed to high winds, or to resist lateral forces such as seismic forces.
Spray foam insulation can be sprayed onto the surface of foundation walls while the house is still under construction. This method can also reduce air leaks in the wall assembly, and can increase the R-value of the wall. The product must be sprayed at a minimum of 1 inch away from the framing, and the foam must be covered with a fire-blocking material to meet fire codes.
Insulating concrete blocks can be a cost-effective option for a new house. The insulating cores can be dry-stacked, or surface bonded to the blocks. In addition to reducing energy loss, the concrete can help moderate indoor temperatures.
For residential applications, fiberglass and mineral wool insulation are commonly available. These materials can be fitted between studs, joists and beams. They are suited for standard stud spacing and joist sizes, and are relatively inexpensive. Closed-cell foam insulation is often more expensive, but can be sprayed into cavities or spaces between studs. It is important to consult a professional before trying any DIY insulation projects.