Skip to main content

Framed Wall Insulation

Installed correctly, framed wall insulation can cut your utility bills, make your home more comfortable, and increase its value.

Older homes without effective wall insulation allow excessive heat loss in winter and heat gain in summer. Insulating walls is a highly effective way to improve your home’s performance. It can reduce your heating and cooling bills, improve comfort with less drafts, and help your home meet increasing performance expectations. If you are undertaking a remodel or renovation project where drywall or exterior siding is removed, conventional insulating techniques can be used. Otherwise, there are two strategies for installing wall insulation. One is to remove the existing wall cladding and install continuous rigid foam insulation under the new cladding. The other option is to use "drill and fill" in which holes are drilled in either the exterior siding or the interior drywall, insulation is installed through the holes, then the holes are patched and finished.

Checklist

This U.S. Department of Energy checklist includes important specifications that can contribute to a complete and quality installation. All work shall comply with these specifications, all relevant codes and standards, and all manufacturer installation instructions. The contractor shall check each box on the checklist below and sign and date at the bottom to certify the work is completed.

Downloadable PDF Version
English Spanish

Preparation


The walls shall be inspected for any evidence of bulk water penetration, knob and tube wiring, or moisture or pest damage, and a list of any potential problems shall be provided to the homeowner before proceeding with the work so remediation can be fully addressed as necessary, including upgrades to the exterior cladding and flashing details as required before starting the work.

Option 1: Continuous Exterior Insulation


Existing wall cladding and trim shall be removed.

The wall sheathing shall be free of any protruding nail heads, screws, or irregularities to ensure a smooth surface for installing the air/water control membrane.

Windows and doors shall be removed as required to allow installation of flashing and air control layer transitions into openings including pan flashing at sills and flashing at the jamb and head.

All exposed cracks and penetrations at sheathing, rim areas, and top and bottom plates shall be air sealed with sealant compatible with the surface.

A weather-resistive barrier (WRB) (e.g., house wrap) shall be installed over the entire exterior wall with seams taped and edges sealed at the top and bottom. Liquid-applied WRBs will not have seams and will not require additional taping or sealing.

Flashing for windows and doors shall be integrated with the WRB to protect the wall assembly from bulk moisture.

Per the contract scope of work, existing windows and doors shall be re-installed or new windows and doors shall be installed in properly flashed openings per window manufacturer’s specifications.

Insulation shall be installed in accordance with the R-value specified for the wall assembly under the contract agreement for this work.

Furring strips or other spacing shall be installed in a vertical orientation over insulation and attached to the structural sheathing and/or framing. Wall cladding and trim shall be attached to the furring strips. Where vinyl siding is being used, the furring strips shall not be required.

Option 2: Drill and Fill with Blown-In Insulation


If the wall cavity has some existing batt insulation, a 1-foot strip shall be cut out along the wall near the floor on either the interior or exterior side of the wall, and the old batt insulation shall be removed to allow proper installation of blown insulation into the wall cavities. Alternatively, an infrared camera shall be used to verify that the blown insulation has adequately filled the wall cavities around the existing batt insulation.


If the walls are balloon framed, blocking shall be installed at the top and bottom of the walls at each floor.

Blown-in cavity insulation shall be installed so it completely fills the cavity, with adequate density per the manufacturer’s specifications to ensure no settling.

If installed from the interior, any holes cut into the interior wall surface shall be patched after the insulation is installed and all cracks and penetrations in the wall surface shall be fully air sealed.

If installed from the exterior, all cracks, penetrations, and holes shall be patched and air sealed after insulation is installed.
Framed Wall Insulation

Tips to Sell Quality Installed Home Improvements

Home Improvement Expert is a valuable tool for organizations committed to quality installed work. The following tips help optimize the value of this tool when selling home improvements:

Trust Matters: Inform homeowners how your work conforms to this world-class expert guidance. Recommend they visit the DOE website as evidence these are indeed official best practices.

Knowledge Matters: Take advantage of the Building America Solution Center as a resource for becoming an expert on these projects.

Clarity Matters: Tell prospective clients to contrast your expert-recommended best practices with other contractors.

Value Matters: Advise prospective clients to insist other bids also include these checklists to ensure equivalent quality work.

Message Matters: Showcase on your website and marketing materials that your company uses the highest quality best practices specified on HIE Checklists.

Experiences Matter: Provide visual evidence contrasting the difference between poor and high quality work such as infrared images; pre- and post-energy bills; short and long warranties; and simple charts and graphics depicting performance advantages.

Related Guides

Guide:

Pre-Retrofit Assessment of Walls, Windows, and Doors

Description
Information guide describing things to consider before retrofitting walls, windows, and doors, including wiring, moisture protection, and lead paint.
Guide:

Blown Insulation for Cavities of Existing Exterior Walls

Description
Guide describing methods of installing blown insulation in exterior wall cavities of existing homes with minimal disruption to occupants.
Guide:

Rigid Foam Insulation for Existing Exterior Walls

Description
Guide describing how to apply an air control layer directly over existing wall sheathing and cover with two layers of insulating sheathing held in place by vertical furring strips.
Guide:

Spray Foam Insulation for Cavities of Existing Exterior Walls

Description
Guide describing how to insulate the wall cavities of an existing home with spray foam.
Guide:

Spray Foam Insulation Applied over the Siding of Existing Exterior Walls

Description
Guide describing how to install spray foam on the exterior of the existing home after framing over the existing siding.

Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.