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Knee Wall Insulation

As one of the biggest sources of energy loss in homes, the attic should be properly insulated. Do you need attic insulation services in the Los Angeles or San Diego area? Contact OJ Insulation today or keep reading to learn more about attic and knee wall insulation!

Insulating Knee Walls & Other Spaces in the Attic

If you’re insulating an attic, the knee walls are important. They are short walls (usually no more than 3 feet high), used to support the rafters in roof construction, with attic space behind them. Knee walls are found in many older houses, where the ceiling on the top floor is an attic or there is a dormer window.

According to the Oak Ridge National Labratory, the open joist ends below the knee wall should be sealed with rigid foam, high-density cellulose or batt insulation. The knee wall (and attic floor) in the attic space behind should be insulated to the recommended levels. You can also insulate and air seal the rafter space along the sloped ceiling of the knee wall space.

Insulation should also be installed in between the studs of knee walls. In addition to knee walls, you should also insulate:

Finished attics

  • Between the studs and rafters of exterior walls and roof
  • Ceilings with cold spaces above

Unfinished attic spaces

  • Between and over floor joists (to seal off living spaces below)
  • Attic access door

Learn more on the U.S. Department of Energy’s website »

Benefits of Knee Wall & Attic Insulation

Insulating (or re-insulating) your attic helps ensure:

  • Lower energy bills
  • A more comfortable home year round
  • Uniform temperature throughout your house
  • Better HVAC performance and efficiency

Unfinished or finished, the attic holds a lot of potential for maximized home energy efficiency and savings.

Knee Wall Insulation Installation in Los Angeles, San Diego & Surrounding Areas

If you have any questions or if you’re ready to start your insulation project in Los Angeles, San Diego or the Bay Area, contact our attic insulation installers today—call 800-707-9278 or fill out the form on this page!

Where should you insulate in your home? Check out our interactive infographic:

Home Insulation

We insulate attics, walls and crawl spaces.

Commercial Insulation

We insulate warehouses, offices, studio spaces & more.

Insulation Removal

Do you need to remove old insulation? We can help.


We work with builders to install fireplaces.

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