As I sit down to write this, it’s -15 degrees F outside. It got down to -24 degrees F during the night, but when I got up my tiny house was sitting at 47 degrees according to the weather station in my kitchen.
I live in a 1972 Wilderness trailer, 24′. The walls and ceiling are two and a half inches thick which doesn’t leave a whole lot of room for insulation! So, 47 degrees in -24 weather is pretty good! I couldn’t see my breath and it’s hard to describe that the house is still pretty comfortable at that. Also, I have a lot of bedding–my bed is super warm. It was great sleeping weather.
But, you can’t keep your house that low. It’s bad for electronics, bad for furnishings and most flooring, and you won’t feel comfortable in those low temps for very long. Eventually, I plan to write more about how I chose my heating and insulation options, but for now, I’d just like to talk about what I’m doing to keep warm this winter.
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I used FatMat to cover the entire ceiling first. I didn’t leave very many gaps, although you can. Originally, I was going to use Reflectix–I love that stuff! But, I’d have had to find a way to fasten it up and you have to leave a gap to get effective R value or it’s just reflective. FatMat is basically a giant piece of butyl tape with a reflective surface. It sticks right to your surface and acts as a sound deadener, vapor barrier, and reflective surface that reflects heat (or cooling) back into the house. I only noticed a slight difference in sound reduction, but there was an immediate difference in cooling when I put it up in summer.
The walls were already there, so I used Dow Froth-Pak Spray Foam Insulation for the walls. This did not go as well as planned. To retrofit spray foam insulation, you have to drill holes, fill, and keep moving which is easier said than done in cupboards and floor-based storage areas. It felt as if everything filled fully in most areas, but it severely over-filled in others, causing the outside walls to bow out in a few places and one inner wall to bow inward. It’s not ideal, but it does maintain the heat in the house until it falls below -5 degrees F.
Every window is covered inside and out with shrink wrap window insulation. If I had it to do over, I’d use self-sticking bubble wrap and next year, I will. But, for this year, there are no drafts coming from any of the windows.
Have I mentioned yet how much I love Reflectix and Aluminum Tape? No? Well, let me tell you. The “curtains” are all made of Reflectix rounded on the corners and covered with fabric on one side. I just used Super 77 spray adhesive to adhere the fabric to the flat panel and bound it with seam binding using a glue gun. They’re attached above the windows with Velcro so that they can come off or be lifted to a hook on a shelf above.
Every cupboard, crawlspace, and cabinet is lined with FatMat on the bottom and Reflectix on the sides and ceiling. Reflectix has to have a gap on one side for effectiveness. That gap is the inside of the cupboards. It’s not elegant, but the space age look fits my decor (plus, it’s inside cupboards, so who sees it?) and reflects light, so it’s easier to see in them.
The really ugly part, though, is the low cabinets because those are all lined with Reflectix inside and out, so you see the Reflectix. By my bed, I have that covered with a blanket that looks like a bed skirt. By the couch, I leave it exposed to reflect the heat from the radiator.
I wanted to use Reflectix underneath. It’s R21 if used in two layers in a crawl space, each layer containing a gap. But, by the time my house was permanently stationed, it was already too cold for anything to stick and it’s all pitted iron under there. I also purchased and prepared 2″ polyiso insulation and stucco cement board siding to skirt the house. I had a plan. It involved gaps. A friend who was helping me and works in construction had a better plan, but he needed to do it. It never got done. So now, my panels are leaning against the house and firmly packed with snow. It works–there was an extremely noticeable change in warmth of the house and floor with that system.
My biggest challenge is the door. It has gaps. No matter how I have tried to fix those gaps with weatherstripping, they have remained the same or gotten worse. It has a layer of Reflectix on the door, one on inside of the screen door, and one more that I need to roll up to leave the house with!
For heat, I have an oil-filled radiator. It works incredibly well for all temperatures above -5 degrees F and too well for temperatures above 25 degrees F. When the temperatures get low like they are now, I supplement with a Big Buddy heater. In truth, it’s a little too large. I wish I had bought a smaller one since I usually only use it on low. This morning, I turned it to medium to warm the house quickly, then down to low when it got up to 60. At around 65 degrees, I let the radiator do its thing.
Of course, I also wear warm clothes and have a blanket on the couch. I never expected to be able to sit around in shorts, although that wouldn’t suck. Stay warm out there!
Please comment below if you have any questions or email them to me at firstname.lastname@example.org. I’m also very open to suggestions, but keep them budget-friendly and doable mid-winter. There are, of course, going to be upgrades come summer, but I’m open to anything I can do right now.