Monday, May 31, 2010

Mapping out the land

I've been stuck on two problems. Later I'll write about the footing details, but right now I want to look at the mapping difficulties. This isn't the first time I've written about this problem, and it probably won't be the last.

The land is a full city block, 270 feet on a side. It is split in to two equal-sized parcels. The orientation is close to North/South, but appears to be about 3 degrees askew from true north. I can accept that error for now. (It appears to be ~7 feet off when I'm 1/2-way between two marked points, calculated as 'tan(3 degrees) * 270 / 2' but my trig is weak.). The great news is that it's already surveyed, with rebar at each of the corners.
I want to cut down as few trees as possible. I love the woods, and putting trees back is hard to do quickly. I know we'll clear some to build the house, and more later, but I want to do it incrementally. So, I walk around the land looking for areas that are already pretty clear, having few trees, or trees that are very small, or short-lived trees like Alder. I want to mark these down on the above map, but that is turning out to be tricky.

I tried using a compass and measuring tape, but ran in to a few difficulties:

- Taking a bearing on a compass is hard! Siting down the needle at a landmark is highly inaccurate. Maybe I can get within 5 degrees.

- The land is full of brush, making it hard to run a tape measure in a straight line.

- The land is full of brush (still?), making it hard to get around.

- The land is full of brush (no!), so I can't put up a reference string around the borders

I tried using the GPS unit that came with my Streets and Trips software, but it seems like the accuracy too far off for my purposes. I am going to try a GPS unit with WAAS next week.

As for getting around in the brush, I tried pulling Salal by hand (it works, but it's really slow) and I tried cutting with a machete (not much luck, maybe I'm not using it right). I'm going to look in to renting a brush cutter (a weed eater but with a blade instead of a string), and possibly buy a small tractor with a loader and excavator (should be useful in the future around the homestead).

Habitat for Humanity

I signed up with Habitat for Humanity, as a way to learn more about house building, on someone else's house. It seems like a good trade: they get my help, I get to learn. Perhaps I could draw some comparisons to apprenticeships.

The first day I got to build a set of steps. They work out of a semi-truck, with a door 4' off the ground. With an experienced carpenter calling the shots, we designed & built steps (6 of them), a landing (3' x 4'), and a handrail. Now that I've been up and down on it a bunch of times, I can say that we did a good job.

They are building 3 houses at once, right next to each other. The excavation of all 3 was done by professionals, as was the concrete work on house #3. The concrete work on houses #1 and #2 are volunteer-built. Some of the volunteers are locals (like me). The last two weeks were filled by the RV Care-A-Vanners, volunteers who travel around in their RVs building houses for Habitat. They're all at least a couple decades older than me, but they can beat me around the work site. Just when I think I'm keeping pace with them, I remember that they do this 5 days / week for two weeks, while just show up when I can. Wow.

On later days I helped build footing forms, then foundation/stem wall forms, then stripped forms off the concrete. Here you can see a detail of how we braced a corner before the pour:


The last couple times it was raining all day. Rain + concrete + excavated glacial till subsoil = pretty dirty work. I still managed to convince Julie to join me one day. Here she is looking sodden:


This activity has taken me away from directly working on our own house, but I suspect that the net result is a time savings, as my skills and knowledge improve. It has been especially helpful to compare the practices of the professional on house #3 to the way the volunteers work on #2. Getting two perspectives helps me see much more of the whole picture.