I suggested to Darwin that we don't have to do the whole house at once. We could insulate under the living room (where we spend the most time) and maybe the office (since it's the coldest room in the house).
But I want to do a little more research after reading the comments. As Patricia W. says, there are so many conflicting ideas about what's best.
Patrick says Insulstar spray-in foam is awesome, and I agree it sounds interesting. I like the idea of sealing up all the cracks and eliminating drafts.
But I worry about spraying something permanent under my floors. I think we have no subfloor - just tongue-and-groove pine. I checked under a vent cover, and though I couldn't see well, I felt all that cold, under-house air breathing on my hand.
I'm terrified of doing anything to the house that can't be changed back at some point in the future, if necessary.
So does this foam attach to the wood? Can it affect the wood? What if we needed to replace part of the floor in future? And is this something we could do ourselves?