Raising the Walls

I have raised the east and south walls of my house! I had some help in the raising from my dad and from Herb Bates. It took days for me to cut, fabricate and build walls and to prepare for raising. When it finally came time to raise the walls, though, it happened in a matter of minutes, and then we were standing in the space of a structure!

I will post a video of the raising soon, but here is a photo:

Building the Walls

I'm building walls today. Over the past week, I have cut & routed them, and yesterday and today I am assembling them with all of the structural lumber - this is the time-consuming part.





These are the box-posts and box header for the south wall. Each one took about an hour to assemble. They will be filled with foam after they are installed. Also note the box of Cheez-it for lunch.





I am assembling the walls on the trailer floor. Shown is the east wall (the most complicated wall) and the south wall on top (2 panels, and I will be adding 2 box posts and 1 box header).

After they are assembled, I will raise the two walls, and I will be able to stand inside my house!

Flipping the Floor

I built my 8x13 floor panel upside down, and had to flip it yesterday, by myself (in pouring rain).














It went well (the last 2 seconds were pretty exciting, but it landed where it was supposed to, with no damage to person or property).

Thank god for simple machines! Levers, ramps & pulleys. A 2x6 can be your friend!

Burning Styrofoam

I have been using the hot knife for the past couple days to fabricate the wall panels.

Burning EPS has a distinctive odor. It reminds me of the smell of Kathmandu in the evening; at the end of the business day, many shopkeepers kept a ritual where they would burn the trash from their day in the gutter. It's a nostalgic smell, that burning plastic aroma (especially when combined with the smell of cheap cigarettes that my crew-mates used to smoke on site). Ah, memories.

But actually, the burning foam, with its thick smoke and smell, made of pure petroleum-derived hydrocarbons, is composed of approximately the same elements as wood smoke: carbon, oxygen and hydrogen. Its smoke is less harmful than smoke from a pine fire.

Styrofoam may not seem to have much "green" cred, being a non-organic petroleum product, but it does have a couple things going for it:

It does create a super-efficient building envelope. My walls, when I'm done, will be as tight as a drum. Air leakage will be minimal, and the insulation value meets or exceeds requirements for such a tiny building. I expect that it won't be difficult to heat my tiny house.

Another benefit of EPS is that it is a durable use of petroleum. I drove to the worksite this morning burning a non-renewable resource (a situation I hope to remedy this summer when I start brewing bio-diesel from vegetable oil). Once petroleum is burnt, it's gone, and the carbon enters the atmosphere. My walls, on the other hand, utilize that same resource daily throughout the life of the building. As long as the walls are standing, the carbon that they are made of is, in the parlance of the green movement, "sequestered", meaning trapped, and providing me with a daily benefit.

Exploring the use of EPS foam in my building envelope is an interesting exercise in sustainability. The panels I am using are waste panels from an inefficient production process; I am saving them from becoming landfill or being incinerated in a waste-to-energy facility. The panels are a durable product which have a net benefit by saving energy over the course of their life-cycle. Large-scale usage of this product may or may not be ultimately sustainable, depending on the design of the manufacturing process. However, for my project, I feel pretty good about using SIPs, and I'm learning a lot in the process.

The sustainability of consuming petroleum products on the large scale that we do is highly questionable. Petroleum, though it is a non-renewable resource, is quite an amazing product. The versatile molecules can be cracked and recombined in a myriad of ways, resulting in an array of products that benefit us every day. Limited, judicious usage of petroleum products can be beneficial. Exploring sustainable alternative to petroleum such as biofuels and soy-based foam products is well worthwhile.

SIP Wall Mockup

Finally, I acquired a hot knife, and construction has resumed.

Here is the tool:








And here is the wall mockup I made with it:









This is an illustration of the corner where the walls & floor meet. Of particular interest is the box post at the corner, built from 2x material, and filled with expanding foam to reduce thermal bridging. Also shown is a surface spline joint, the method of joining two panels with OSB splines.






Here is a drawing showing the corner box post.

Hot Knife

I have this tool that is hanging my project up: a foam-cutting hot knife. I need it to progress to the next step of assembling my envelope. The tool consists of an electric heating element that creates enough heat to melt the EPS foam cores of the structural insulated panels, in order to create voids to insert framing lumber into the panels.

I could buy the tool, but that is $150 or $200 that I'd rather not spend for a single-use tool.

I have been foiled in two attempts to make such a tool: first, some unsuccesful trials with a torch-heated metal bar nixed the idea of a propane-heated element; second, I tried bending heating elements from an electric stove, with dubious results.

I think that I finally found a place that I can rent a hot knife: Winter Panel in Brattleboro VT. I'll be going through tomorrow, and I'll pick it up.

I'm chomping at the bit to get some structure up in the air, and to see this project start to take shape!!!

CUBIT

Could
U
Build
It
Tinier?