How to build recessed light cans in your Eichler ceiling

Since we were re-roofing, we figured it was a good time to add these UL, water/IC-rated recessed light cans over our shower and bathtub.

Steps I took:
1. Cut a hole in the ceiling slightly larger than the light can using a sawsall.
2. Build a simple 2×4 frame to mount the can to – mimicking a stud bay.
3. Drill a hole and run wire to the can.
4. Mount the can to the frame.
5. Secure the frame to the roof deck.
6. Cover with plywood.
7. On the inside, I used bondo to fill the T&G grooves in the ceiling around the can where the light cover goes – to seal and protect from moisture (not pictured).

The whole box is now buried under the new foam roof, so if it ever goes kaput – I’ll have to either dig it out from above, or cut it out from below. If I had to do it again, I’d probably make the enclosure taller and add a weather proof access lid to it for future maintenance..

I’m interested to hear how other people have done this differently?

*Always consult a licensed professional when dealing with electrical systems.