Floor insulation complete

I did it; I put in isocyanaurate under my floor. The "joists" or crossmembers holding up the floor are 3" tall, so there's a 3" gap between the bottom of the floor and the frame rails. I inserted the insulation in those gaps, just like you'd do in a house, except I didn't use the pink stuff, I used these 2" sheets of insulation. The floor itself is 1.75" thick wood, so I used 3" wood bullets with a 1.75" fender washer to screw the insulation into the floor above.

Above the floor is a sheet of polyethelene, a sheet of some kind of sound-dampening insulation, then a sheet of spongey stuff to make the floor give, then finally my fake-hardwood pergo.

I've noticed already that the floor stays warmer, especially after driving (the air whizzing across the underside of the truck cooled the floor down a lot). This is good. We'll see what happens after a night of cold air. Temperature here lately has been very warm during the day, like 65 degrees, then down to a cold 45 degrees at night. It's an unusually dry winter so we're getting desert-like temperature fluctuations. The wind is from the east so we're not getting ocean humidity.

I notice it's also a bit quieter in here now too! That's a big win.

The whole project cost me like $80. It took me from 9am to 6pm. I was exhausted afterwards-- I am not used to working like this. But it felt good to use my body for a change, instead of spending 14 hours a day in front of a computer.

I hope this insulation will help in the summer too. I noticed that the van would get intolerably hot on some afternoons after the sun went low enough to heat up the ground underneath the van. I noticed that the floor would be warm. I think the insulation will help prevent that heat from radiating inside. If this summer will be like this winter, I'll have plenty of opportunity to find out.

Happy summer in California

This is pretty amazing, it's like 65 degrees, it's New Year's Day, January 1st.

I've been spending lots of time on the beach. I love it. It's warm and sunny.

On the days we've actually had winter weather, I have found ways to use passive solar heating too: I just open up the door to my box, park facing south, and make the huge 3-sided solar collector known as "The Cab" do its work to heat the place up.

It was cold enough a few weeks ago that I realized there's a huge oversight in my insulation: the floor! The floor is not insulated at all. And it was getting freezing cold in here, due to the floor. So I have to go buy some isocyanaurate sheets, cut them up to fit in between the beams of my box, and insulate the floor. Then it'll stay toasty in the winter, and, I think, stay cooler in the summer too!

I noticed last summer that the van stayed so wonderfully cool in the mornings on hot days, but as soon as the afternoon came it got way too hot. And I couldn't figure out where the heat was coming from. I think heat was rising up off of the road in the afternoons and heating the van up. So maybe insulating the floor will help me this summer, which, if this is any indication, is going to be an exceptionally hot one.