Tuesday, December 21, 2010

How to move a yurt platform

After taking the yurt down, we still had some daylight, so we started working on the platform, but it took all of the next day to finish taking it apart, and a Julie and I spent 1/2 of a 3rd day wrapping up. The platform was way more work than the yurt. Keep that in mind if you ever think of getting a yurt quick-and-easy structure. (It is possible to put them on the ground with no floor, but that's more temporary.)

Taking apart the platform was so hard that I wrote a question about it on the Home Improvement Stack Exchange. From that question:

Decking was 1 1/8" tongue-and-groove plywood, fastened with 3" Robertson (square-drive) screws. The deck was painted after installation, so some paint was in the screw heads. A regular cordless drill wasn't strong enough to turn these screws, but an combination drill / impact-driver was able to do it. However, maybe 1 in 10 screws had their drive heads stripped instead. Too much friction / too much torque. We used a Sawzall to cut those screws out. Went through 4 Sawzall blades.
Framing was 4" x 6" joists on 4" x 4" posts on concrete piers. Most lumber was pressure-treated, but about 1/3 of the joists were not. Beam-to-post caps were nailed in to the joists and posts, 3 nails on each side. We spent a lot of time hammering a Cat's Paw under the nail heads, and then prying them out.
Insulation was 4' x 8' sheets of 2"-thick foil-faced foam board, between the joists, secured with 1/2" x 1" lath strips, which were fastened with 2" screws. To be able to get the Sawzall in to place, we crawled around in the dirt under the yurt to remove the foam. These screws were also hard to remove, and sometimes we had to break the lath instead.
I was tired after each day of work, but the 3rd day left me deeply exhausted. The work of loading 30 concrete footing blocks kicked my butt. Many of them I had to carry up hill. I'm guessing they weighed 50 lbs each, so we put 1500 lbs of concrete in the back of the truck. Maybe more.

My new yurt location is pretty flat, so I don't necessarily need the posts. I can just lay the joists directly in to the brackets on the concrete footer blocks. However, I'm considering using the posts anyway, just cut short (6"? 12"?).  It would be easier to crawl under the yurt with a little more space. Getting all 30 blocks in just the right location, with the ground under each block perfectly flat, is tricky. Making all the blocks be exactly the same height is even harder, but cutting posts to the same length is easier. Also, I already have all the posts and brackets I would need. Downsides are more fastening required and the need for steps up in to the yurt.

How to move a yurt

Last week we took apart the yurt. I tried to find information online about how to do that, and couldn't find much. I wish I could have done time-lapse photography of the operation, but I don't really know how. So, here's a blog post that I hope someone will find useful when they want to do the same thing.

This yurt is a 30' model, which is as big as they get. That's 700 sq. ft. It seems like there's a practical limit at that size. It was made by Pacific Yurts in 2006. I wrote the company and they sent me a PDF of the construction manual, and said "just follow it backwards". That was helpful, but we still had to figure out a lot as we went.

It was built on a hillside. That meant that reaching some parts of the outside wall was really hard; luckily we had a long extension ladder.

1. Scaffolding

While the walls are only ~7' high on the perimeter, the center is more like 14' up. The instructions recommend scaffolding, so we rented some from an equipment rental place that was close by. We had a choice of 7'-long or 10'-long platforms. 10' would be too long; get the 7'. Each unit gets you 5' up, so two units give you a 10'-high platform, as recommended by the manual. Any taller wouldn't fit, and any shorter wouldn't be enough to manipulate the canvas cover.

We rented the scaffolding for a week for $55. That night I got sick with a stomach bug, and the equipment sat idle for 5 days. Finally I felt well enough to work and we assembled the troops. I called all my friends & a couple professional builders, and ended up with 4 adults: A pro, a young woman who helps in Reid's nature class, wife Julie, and myself. Reid was also with us.

2. Bubble.

There's a plastic dome in the middle of the roof, called the bubble. Under it is a small fly screen, which came off easily. After removing the bubble we tied on a 1/4" rope and slid it down the roof, using the rope to slow the slide. The instructions said to put it on a piece of cardboard, but we just flipped it upside-down. It was easy.

3. Walls.


The wall canvas hangs on small hooks from a string at the edge of the roof canvas. At the bottom it is held in place by a screw every couple feet. The screws came out first, then we unhooked and removed the walls. On the downhill side of the yurt this was tricky, and the long extension ladder was the only way were able to do this. I'm grateful that the guy I hired happened to bring one. We folded up the wall panels and loaded them in to the truck.

There were at least a dozen yellowjacket nests under the edge of the roof at the top of the wall. Luckily we were doing this in December, and all they were all in their winter homes underground.

Under the wall canvas was a foil-faced insulation layer, held in place by zip ties at the top. We clipped them off and the insulation panels dropped away. We folded & loaded these, too.

At this point, the outer walls were only lattice, which looked pretty cool. I could imagine using something like that in Hawaii in a remote area. Lots of airflow.

4. Roof material

The roof is a layer of heavy canvas, over a layer of foiled-faced insulation, over a light cloth layer, resting on a wooden frame.

A friend who has the same yurt said that getting the canvas on to the roof was the hardest part of the job. Two of us stood on the scaffolding, which put the compression ring at waist height. We grabbed the canvas on one side and started pulling, bunching it up in front of us. When it was all gathered, we passed it over our heads, and then pushed. The two on the ground pulled, and the whole thing slid to the ground in a clump. We spread the whole thing out flat (in the nearby septic drain field), folded it in half, then folded the sides in until they met, and then folded in half again. This clump we hauled to the truck. This step would have been hard with only 3 adults, and extremely difficult with only 2.

Meanwhile the light insulation layer was trying to lift off in the breeze. It is made of a series of wedge-shaped panels, taped together with aluminum tape, and they were trying to separate. Power lines from the street passed right over the yurt, and they threatened to touch. The wires are insulated, but I was still wary. Luckily we were able to move the insulation away from the power lines quickly. We rolled the insulation up, folded it in half, and loaded it in the truck.

The light cloth cover was easy to bundle up and carry away.

5. Rafters


The radial rafter system is clever. One end has a metal pin that fits in to a hole in the compression ring. The other end has a sawn slot, which fits around the tension wire at the perimeter. A screw in the end of each rafter helps make sure the wire doesn't pop out in a windstorm.

Before removing any rafters, we had to remove the "safety cable" that runs through some holes in the rafters. There are actually 4 holes in each rafter, to allow for an upgraded "snow and wind kit" but this yurt didn't have that element. The wire is held tight with cable clamps. My plain old step ladder was not quite high enough to reach this; make sure you can reach with your ladder. Once the clamps were removed, we unrove the cable and coiled it up.

To pull a rafter out, I stood with my back to the lattice wall and grabbed the rafter over my head. I pushed out on the wall with my body, while pushing the rafter inwards with my hand. When the wire was clear, I then pulled the rafter outwards. Another person in the scaffolding held the other end of the rafter to help pull the pin end out of the compression ring. I had this idea that I would remove every 8th rafter, then every 4th, then every 2nd, to keep the tension even. This was not helpful. I should have just removed every other one to start.

As the number of rafters decreases, the tension cable gets a little lose, and the roof system gets floppy. This is a risky part of the process. I wore a hard hat, and did hit myself in the head with a rafter once. No kids allowed at this point.

Eventually we got down to 3 rafters. I unhooked one, and had a helper hold it in place. Then I unhooked another & gave it to another helper. Then I unhooked the 3rd, and held it myself. The 4th adult was still on the scaffolding, and held the compression ring. We then lowered the whole thing until the ring was on the platform. We unhooked the rafters and stowed them away.

The rafters are quite long (maybe 15'), and would not fit in the back of my truck, even though it's a full-size truck with a long (8') bed. The guy I hired had a compact truck (Toyota Tacoma) with a lumber rack, so we used that. But before loading, we took down the lattice walls so they wouldn't be in the way.

We got to this point in about 2 hours; way faster than I expected.

6. Walls


The walls are a relatively light lattice framework, riveted at every crossing. One section covers approximately 3/4 of the area, and one covers 1/4 of the area. The doors go in between the two sections of lattice. They are bolted to the door frames and attached to the platform with metal brackets. The tension cable lays in the crotches at the top of the lattice; we removed the tension cable at this point.

We removed all the fasteners, then popped out the smaller lattice section. It's quite unwieldy. We compressed the lattice, which is tricky because it wants to bend instead of compress. I wonder if a brand new lattice moves more easily? It was noisy, and we may have snapped some of the wood. It's also really easy to get fingers pinched as you do this. (Hint: the more you compress the lattice, the easier it is to roll it up. So, compress all the way!)

The large lattice section was even harder to manipulate. For a while we left it standing in a cylinder on the platform. The wind blew it over the side and down the hill. This was a bad idea. We should have compressed it all the way and secured it somehow.

Once the lattice is down, the doors are not very stable. They are held in place with a pair of screws in to the platform. Get these screws out and lay the doors down right away.

At this point the yurt was completely disassembled. We hauled everything to my garage to keep it out of the weather until the new platform is ready.

Next time: taking apart the platform.

Monday, December 6, 2010

Meet Coach

I just bought an RV. The sellers called him "Coach":


It's very clean for it's age, and many of the appliances have been replaced recently. I'm enjoying getting to know all the different parts. It's like a boat + a truck + a house, so there's lots of parts!

Here's the floor plan:


It's old enough to be cheap, but not old enough to be a classic. It was on Craig's List for $8000. I took it to an RV mechanic and he pointed to a bunch of problems ranging from serious to trivial. I ended up buying it for $6000, and spent $2000 to have him fix the most important items:
  • Reseal the roof
  • Fix hot water heater
  • Replace water pump filter
  • Repair propane gas leak