Insulated Headers

Scope

Reduced Thermal Bridging

 

Install headers with a minimum R-3 insulation value in wall assemblies with 2x4 framing, or equivalent width, and R-5 for all other assemblies (e.g., with 2x6 framing). Use one of the methods listed below or an equivalent assembly*:

1. Continuous rigid insulation sheathing
2. SIP headers
3. Two-member headers with insulation in between
4. Single-member headers with insulation on one side

* All items of 4.4.5a-4.4.5e must be installed to comply with 4.4.5 and ENERGY STAR.

Notes:

Up to 10% of the total exterior wall surface area is exempted from the reduced thermal bridging requirements to accommodate intentional designed details (e.g., architectural details such as thermal fins, wing walls, or masonry fireplaces; structural details, such as steel columns). It shall be apparent to the Rater that the exempted areas are intentional designed details or the exempted area shall be documented in a plan provided by the builder, architect, designer, or engineer. The rater need not evaluate the necessity of the designed detail to qualify the home.

Mass walls utilized as the thermal mass component of a passive solar design (e.g., a Trombe wall) are exempt from this item. To be eligible for this exemption, the passive solar design shall be comprised of the following five components: an aperture or collector, an absorber, thermal mass, a distribution system, and a control system. For more information see the Energy Savers Website.

Mass walls that are not part of a passive solar design (e.g., CMU block or log home enclosure) shall either utilize the strategies outlined in Item 4.4 (of the ENERGY STAR Thermal Enclosure System Rater Checklist). Or, the pathway in the assembly with the least thermal resistance, as determined using a method consistent with the 2009 ASHRAE Handbook of Fundamentals, shall provide ≥ 50% of the applicable assembly resistance, defined as the reciprocal of the mass wall equivalent U-factor in the 2009 IECC – Table 402.1.3. Documentation identifying the pathway with the least thermal resistance and its resistance value shall be collected by the rater and any Builder Verified or Rater Verified box under Item 4.4 (of the ENERGY STAR Thermal Enclosure System Rater Checklist) shall be checked.

Header insulation shall be > R-3 for wall assemblies with 2x4 framing, or equivalent cavity width, and > R-5 for all other assemblies (e.g., with 2x6 framing). Compliance options include continuous rigid insulation sheathing, SIP headers, other prefabricated insulated headers, single-member or two-member headers with insulation either in between or on one side, or an equivalent assembly, except where a framing plan provided by the builder, architect, designer, or engineer indicates that full-depth solid headers are the only acceptable option. The Rater need not evaluate the structural necessity of the details in the framing plan to qualify the home. Also, the framing plan need only encompass the details in question and not necessarily the entire home. R-value requirement refers to manufacturer’s nominal insulation value.

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Description

In load-bearing exterior walls, structural headers are placed over windows and doors to pick up the load from the building above and transfer it to the posts on both sides of the window or door opening. Structural headers are a point of increased heat loss because they are made from solid or laminated framing timbers with no insulation. Proper sizing of headers allows better insulation and saves wood. Insulated headers reduce heat transfer to keep the home warmer in the winter and cooler in the summer.

 

In many cases, headers are overdesigned, consisting of solid wood layers that add up to the full 4- or 6-inch wall thickness. (For example, a header made of two 2x12s sandwiching a ½-inch layer of plywood is installed when a header comprised of thinner layers of plywood or OSB would provide enough structural strength and allow room for a layer of rigid foam.) In some cases, no solid wood layer is needed; in nonbearing walls, the header space can be left open and filled with insulation instead. Structural headers are not required in most interior walls or in gable-end walls with only non-bearing trusses directly above. A single flat 2x4 or 2x6 can be used as a header in interior or exterior non-bearing walls for openings up to 8 feet in width if the vertical distance to the parallel nailing surface above (usually the top plate) is not more than 24 inches. For such non-bearing headers, no cripples or blocking are required above the header (2009 IRC R602.7.2). Insulated or open headers should be used except where a framing plan provided by the builder, architect, designer, or engineer indicates that full-depth solid headers are the only acceptable option. [See 2009 IRC Tables R502.5(1) and R502.5(2) for header span requirements.]

Insulated headers can be made of rigid foam sandwiched between two layers of plywood or OSB or one layer of foam and one layer of plywood, or structural insulated panels. These can be built onsite, or pre-fabricated insulated headers can be purchased.

Headers are installed by the framers using plans provided by the designer or architect. This task should be included in the contract for the appropriate trade depending on the workflow at the specific job site. High-performance branding programs and the IECC code require that builders meet specified insulation levels. See the “compliance” tab for these specified insulation levels.

 

 

Firgure 1 - Structural headers are used above the windows on the bearing walls in this drawing but the wood layer is properly sized (no thicker than necessary) to allow for a layer of rigid insulation. On nonbearing walls, the headers are open allowing for the space above the windows to be insulated to the same level as the rest of the wall. 

 

How to Install an Insulated Header on a Bearing Wall

1. Use pertinent code requirements to determine minimum header lumber requirements. [See for example, 2009 IRC R602.7 and Tables R502.5 (1) and (2).] Install a properly sized prefabricated header or fabricate the header onsite from one piece of rigid foam and one or two pieces of plywood; see Figures 2 and 3.

Figure 2 - Insulated header made of two pieces of plywood that sandwich a layer of rigid foam insulation 

 

 

Figure 3 - Insulated header made of one piece of plywood (or two if needed) aligned with exterior wall, leaving room for insulation toward inside 

 

 

2.  Eliminate jack studs (also known as shoulder studs) on load-bearing walls by hanging structural headers with metal hangers instead. Note that jack studs are not needed on non-bearing walls. Eliminating jack studs will reduce the available nailing area for siding and trim if nailable sheathing (e.g., plywood or OSB) is not used. If needed, attach a 2x2 wood nailer to the outside edge of the stud for siding attachment.

Figure 4 - Insulated headers can be hung with metal hangers instead of jack studs to reduce lumber usage 

 

 

How to Insulate a Header on a Non-Bearing Wall

 

1. Install a single flat 2x4 or 2x6 at the top of the door or window rough opening as the header in interior or exterior non-bearing walls for openings up to 8 feet in width if the vertical distance to the parallel nailing surface above (usually the top plate) is not more than 24 inches. For such non-bearing headers, no cripples or blocking are required above the header (2009 IRC R602.7.2). Insulate the cavity above the header in the same manner as the rest of the wall.   

 

 

 

Figure 5 - Structural headers are not needed on nonbearing walls; the open space above the window can be filled with the same insulation as the other wall cavities 

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Ensuring Success

It may be possible to detect heat loss at the headers with an infrared camera, if a sufficient temperature difference exists between the outside and the conditioned space of the house. The quality of installation of the insulation should be visually inspected by the site supervisor before the drywall is installed.

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Climate

No climate specific information applies.

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Right and Wrong Images

Presentations

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CAD Images

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Compliance

ENERGY STAR Version 3, (Rev. 6)

Thermal Enclosure Checklist, Reduced Thermal Bridging. All headers above windows & doors insulated. Header insulation shall be ≥ R-3 for wall assemblies with 2x4 framing, or equivalent cavity width, and ≥ R-5 for all other assemblies (e.g., with 2x6 framing). Compliance options include continuous rigid insulation sheathing, SIP headers, other prefabricated insulated headers, single-member or two-member headers with insulation either in between or on one side, or an equivalent assembly, except where a framing plan provided by the builder, architect, designer, or engineer indicates that full-depth solid headers are the only acceptable option. The Rater need not evaluate the structural necessity of the details in the framing plan to qualify the home. Also, the framing plan need only encompass the details in question and not necessarily the entire home. R-value requirement refers to manufacturer’s nominal insulation value.
 

DOE Challenge Home

Exhibit 1: Mandatory Requirements. Certified under ENERGY STAR Qualified Homes Version 3. Ceiling, wall, floor, and slab insulation shall meet or exceed 2012 IECC levels and achieve Grade 1 installation, per RESNET standards.

2009 IECC

Table 402.4.2 Air Barrier and Insulation Inspection Component Criteria, Walls: Corners, headers, narrow framing cavities, and rim joists are insulated.* Table 402.4.2 Air barrier and thermal barrier: Exterior wall insulation is installed in substantial contact and continuous alignment with the air barrier. Air permeable insulation is not used as a sealing material.*

 

2009 IRC

Table N1102.4.2 Air Barrier and Insulation Inspection Component Criteria, Walls: Corners, headers, narrow framing cavities, and rim joists are insulated.* Table N1102.4.2 Air barrier and thermal barrier: Exterior wall insulation is installed in substantial contact and continuous alignment with the air barrier. Air permeable insulation is not used as a sealing material.*

2012 IECC

Table R402.4.1.1 Air Barrier and Insulation Installation, Walls: Corners, headers, and rim joists making up the thermal envelope are insulated.* Table R402.4.1.1, Air barrier and thermal barrier: A continuous air barrier is installed in the building envelope including rim joists and exposed edges of insulation. Breaks or joints in the air barrier are sealed. Air permeable insulation is not used as a sealing material.*

 

2012 IRC

Table N1102.4.1.1 Air Barrier and Insulation Installation, Walls: Corners, headers, and rim joists making up the thermal envelope are insulated.* Table N1102.4.1.1, Air barrier and thermal barrier: A continuous air barrier is installed in the building envelope including rim joists and exposed edges of insulation. Breaks or joints in the air barrier are sealed. Air permeable insulation is not used as a sealing material.*

*Due to copyright restrictions, exact code text is not provided.  For specific code text, refer to the applicable code.

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Case Studies

References

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