Insulating the floor...

...was a bit of a disaster.

If there exists an option that is simple and elegant (and there usually does), then it's probably the right decision.  I took a different route when I decided to insulate the floor of my home.  The work has been messy, slow, expensive, and frustrating.  I spent a few days cutting layers of rigid foam into puzzle pieces and placing them in between floor joists.  Picture kernels of foam flying everywhere.  I now have 6" of foam insulation in the floor...overkill!  On the bright side, Nate pointed out that after using all that foam, my trailer is now amphibious and capable of handling arctic temperatures.  Stay tuned for my float trip to the coast via the Columbia River.

I have ideas on how the whole process could have been more clever and smooth and will update this posting when I get a chance.  I've been busy framing walls lately!

If I could do the floor again, I would insulate from underneath the trailer once the structure was waterproofed.  That would allow me to frame in the rain with less concern about my materials getting wet and trapping moisture beneath the floor.  As far as I'm concerned, this house will live its life in the Pacific Northwest, so I probably could get by just fine with less foam in the floor.  It's a small space and it will heat up and cool down relatively quickly.  If the floor gets cold in the middle of the winter, a rug placed in strategic areas would probably be just fine.  Another advantage of insulating after the structure is built is that I could more effectively seal the metal underbelly against the trailer frame with caulking and spray foam.  I would also have easy access to drill holes through the floor for plumbing and utilities.  Oh well.  Keep it simple and modifiable if you're an amateur.