Hacker News Reader

And for maintaining a proper vapor barrier and insulation - two things rather critical to asset value and livability respectively, in most climates.

You can also put insulation on top of them to make your room more temperature efficient. Also prevents the need of dusting your roof joists, since they are effectively sealed.

Ha touche. Although I would say my ceiling is just the inside part of my roof :P

I guess it depends on how your house is made.