We’re doing a top-to-bottom remodel on a 50-year old ranch home. We removed all of the attic insulation in this process and lighting will be installed before we re-insulate the attic. The lighting includes several recessed LED downlights. The fixtures are ICAT rated and include gaskets on the trim flanges that – in theory – seal the fixture to the drywall.

Two potential problems:
1. I’m skeptical the minimal gaskets will provide an effective seal.
2. If we need to pull down the fixture for maintenance (e.g. a defective driver, which is connected to the fixture, in the attic), we’ll disrupt the insulation above.

I understand that “top hats” can be installed. Simple covers that go over the fixtures in the attic, cut to pass the wiring through and are foam-sealed to the drywall / light frame / wiring. Rated for the purpose. The commercial products I’ve found so far – made by Tenmat (for example, https://www.tenmatusa.com/insulation-protection-covers/ff130e-recessed-light-draft-stop-cover/) – are pricey at $20 and up. These are round, appropriately named. (

For the fixtures we’re using, a rectangular cover would fit better, providing more room to separate the driver from the fixture. Our insulation contractor says they’ve had good luck making their own boxes using Thermoply, using foil tape to seal the joints. This seems like a good way to go. They can be fabricated to meet the size requirement and I believe Thermoply is an appropriate material from a fire-rating standpoint.

A box could also be made from drywall but harder to work with than Thermoply.

Any experience with this approach or other products / methods you’d recommend?

Thanks in advance.
Doug