insulation

Wintering in a Tiny Home

tiny house
Wow, what a crazy winter we have had this year! When I first talked to the people who are hosting my tiny home and me, they told me snow was more of a novelty than the norm. So I wasn't expecting multiple snowstorms, feet of snow on the ground for months, and days when I couldn't get to work because I had to wait for the rural roads where I live to be plowed. They say this has been a record winter, worse than any in 20 years, so maybe I should consider myself lucky to have had this experience. Don't get me wrong, snow can be beautiful when it's falling and waking up to a blue sky and snow topped ponderosa pines is downright magical. It's the cold, the shoveling and the treacherous road conditions dealt with on a daily basis that remind me why I moved away from a snowier climate. Can you tell I'm ready for spring?
tiny house
I am happy to say my tiny house has held up to the snow and below zero temps. Well mostly. My cantilevered door awning did manage to build up enough snow to split and rip apart the siding and furring strips I had lag screwed it to so I'm going to have to do some repairs to get it reinstalled. Luckily I had added a 2x4 across the horizontal supports so the polycarbonate didn't break.

I did invest in a heated water hose this winter and it was the best decision I could have made. For around $100, I have had running water all winter long. We didn't end up installing a frost free hydrant but the utility shed structure and a little bit of insulation around the water hose connections were enough to keep the line from freezing. I had guessed that I would be dealing with colder weather for a longer period of time than I had in Portland, and boy was I right! I highly recommend buying and using one if you live in a climate with below freezing winter temps.
heated water hose
Also, I bought an oil filled radiant heater to use as the primary heat source for my home. I usually had it set on the low or eco modes at 65 degrees (the lowest temp possible), and that was more than adequate to keep the house warm even in sub zero conditions.
oil filled radiant heater

Roxul Comfortbatt: Interior Insulation

I had such a great experience with Roxul Comfortboard for my exterior insulation wrap that I decided to use another Roxul product to insulate my wall cavities. Roxul Comfortbatt has some of the same properties as the Comfortboard. It is fire resistant, sound absorbent, mildew resistant, and has a high R-value per inch. A 3.5" batt for a 2x4 wall is rated as R-15. That's 4.3 per inch! (Comfortboard is 4.6 per inch due to higher density.) A fiberglass batt is typically R-11 or R-13 and that is if it is installed correctly with the paper facing stapled to the studs and precise cutouts around wiring and boxes. Perfect install is difficult since the batts usually end up squished in places or have air gaps around penetrations. Fiberglass batts also sag over time. Plus it is extremely irritating to the skin.
Due to poor experiences with fiberglass, more people are turning to foam for insulation. While foam has a higher R-value per inch (R-4 to R-6) and is very rigid, it off gasses over time and looses some of it's R-value. The manufacturing process is also toxic to the environment and the foam is not recyclable.
Rock wool insulation is made from stone rock spun into fibers that create a rigid batt which friction fits into the stud cavity. You simply stick in the flexible edge of the batt with the W markings next to a stud and then press in the other side. You can easily make cuts for narrower cavities or boxes with a bread knife without compressing the batt. Long clothing, gloves and a mask are recommended for installation but I installed some of it in a T-shirt and was not bothered by the fibers.
I ordered the insulation online from Lowe's since they don't carry it in the store and it was less expensive than another distributor in town. I paid about $275 for 7 bags of insulation which covered all of my walls and ceiling. The Lowe's location is also convenient for pick up. I could have had it delivered to site for around $80 which is what I paid for the Comfortboard but that came from Tacoma, WA. I thought it would be more fun to pick it up with my Subaru too.
Some days I really want to have a truck to haul around materials and pick up things found on Craigslist. I will likely trade my Subaru in for a Toyota Tacoma in the next year but it really is fun to see what I can do with my Roo. And the looks on people's faces as I drive by is priceless ;)
It's been great to feel the difference the insulation has made inside the house! What most people don't realize is that insulation helps keep spaces cool as well as warm. With temps in the 80s and 90s lately, it was getting quite hot inside. Installing the metal roof helped reflect some of the sun's rays but the Roxul has kept the interior much cooler. Now my walls have an R-value of 21 (typically R-13 for a 2x4 wall) and my roof is R-25 (typically R-38 but it would be difficult getting it there in a tiny house without an attic). My extruded polystyrene floor has the highest R-value at 27.5 for 5 1/2". If I build again, I would use Roxul batts in the floor where I could get R-23 (typically R-30). But with a space this small, the insulation should be sufficient. (Can you tell I work in the energy efficiency field?)
More photos on my flickr!