Knee Wall Insulation: Why Finished Attic Rooms Are So Hot!

Send us Fan Mail

Is your finished attic, bonus room, or room over the garage always hotter than the rest of the house in summer and colder in winter? Most homeowners assume they need a bigger HVAC system, but the real problem may be hiding behind a knee wall in the attic.

In this video, Michael Church from Crawl Space Ninja explains one of the most overlooked attic insulation and air sealing problems: open floor cavities behind knee walls. You'll learn why fiberglass insulation alone often fails, what building scientists call "wind washing," how attic air sneaks under your floor, and why many contractors miss this critical detail.

You'll also learn:
✅ What a knee wall is
✅ Why finished attic rooms are uncomfortable
✅ How open floor cavities affect HVAC performance
✅ Common ductwork problems behind knee walls
✅ The proper way to insulate and air seal a knee wall assembly
✅ Why you should check the building envelope before replacing HVAC equipment

If you're struggling with a hot upstairs room, high energy bills, or poor comfort in a finished attic space, this video may save you thousands of dollars.

🆓 FREE Attic Air Seal & Insulate Guide:
👉 https://buymeacoffee.com/csninja/e/478323

📖 Seal First, Insulate Second: 
👉 https://buymeacoffee.com/csninja/e/546355

My Favorite Radiant Barrier — US Energy Products
👉 https://amzn.to/4vnRixQ

🛒 DIY Store — Professional-Grade Materials:
👉 crawlspaceninja.com/supply

📞 Book a Personal Consultation with Michael:
👉 https://buymeacoffee.com/csninja

Support the show

Check out Michael's book, "Crawl Space Repair Myths-Busted" now available on Amazon!

Schedule a consultation: https://buymeacoffee.com/csninja/extras

Need help: https://crawlspaceninja.com or https://supply.crawlspaceninja.com