Insulated Window Headers
Thermal losses in homes occur most frequently at windows and doors. Windows alone can account for at least 25% of energy loss, which is why single-pane windows need to be replaced. Aside from upgrading to double-paned windows with some combinations of added features such as low-E coatings and spectrally selective glass, what else can you do to improve your home's energy efficiency?
One way to address the energy inefficiency of windows is the headers. Insulated window headers in various sizes are now available, and they create a thermal break without jeopardizing structural performance. With this thermal break, you can reduce heating and cooling consumption by drastically reducing or even eliminating heat transfer across the header.
Insulated Window Headers
When you consider that the typical home may have several dozen square feet of header area, replacing the headers at the same time you replace your windows could radically improve your home's overall thermal performance.
In fact, replacing the solid headers above windows and doors with insulated headers can significantly increase the R-value of your walls, almost tripling it in some cases. Insulated headers can do this because they utilize technology from another innovative construction method called Structural Insulated Panels, or SIPs.
This SIPs-influenced process uses machine stress-rated wood flanges with a layer of EPS foam insulation and places them between two OSB web panels. This creates lightweight, insulated headers with a thermal break that also maintains structural integrity. It also produces a strong and cost-effective alternative to beam headers.
The window manufacturers claim that insulated headers are not only straighter, but also more dimensionally stable. Insulated headers are also less prone to the stress of contraction and expansion that plagues solid headers, so they are more resistant to the shrinking, warping, and distorting that causes drywall to crack in conventionally framed headers.
Insulated headers come in multiple depths and widths, suitable for both 2x4 and 2x6 framing, and they can also be factory cut to builder specs. They are single-piece units and don't require any additional installation labor. It only takes one person to install them and the quick-and-easy process is similar to installing regular headers (they rest on jack studs). Insulated headers do not twist, split, or warp during replacement window installation.
Insulated headers can replace doubled 2x12s up to 22-foot spans (depending on the load). They are more expensive than regular solid beam headers, but the short-term cost increase in materials can be offset by the fact that there is less insulation to buy due to the integral foam core, lower labor costs as a result of the ease of installation, and of course long-term energy savings.