Tuesday found us on the way into Kamloops with a list of supplies we needed to complete the perimeter drain for the building, the thermal wrap and the rest of the materials to do the tire walls. We are now on our third row of tires. Sean and Anna left last Saturday on errands in the lower mainland. We sure miss their help! Things go slower without them!
As our tire walls increase in height, we need to start backfilling so that we have a same-level surface to work on. That meant putting in the perimeter drain and starting the thermal wrap. On Monday evening we sat down and made an extensive list of supplies that we needed for Wednesday, which is when we asked Alvin to return and do some trench digging. On our way into Kamloops Tuesday morning Chris hit the cell phone and started to get some prices.
Our biggest learning curve was on what kind of rigid insulation to buy for the thermal wrap. The thermal wrap is the layer of rigid insulation that is buried around the house (to the height of the roof) that contains the heat around the house and prevents any thermal heat we acquire in the house from seeping slowly out into the ground. For a better explanation of this go to Earthship Biotecture at: http://www.earthship.net/index.php?option=com_content&view=article&id=27:thermal-wrap-turbo-charge-your-earthship&catid=49:comfort&Itemid=30
Rigid insulation differs in kind and price. The blue kind is the one more generally accepted for burial. However, we found a white brand that was half the price. Most sales people told us that it was not acceptable for burial. However, we saw a little bit of text on the promotional material that indicated otherwise. Sharon Donchi (who used to arrange log home shows and now works at Home Depot) called the technical rep for this company and it turns out that it can indeed be buried. We however, wanted to achieve an R12 value, which is generally accepted by Code for a traditional basement wall. This less expensive brand was only R8. By the time we ran the numbers the blue brand was still more expensive but probably by only 10-20 per cent. Using the white brand may have been less expensive, but it did have a lower compression value AND it is not generally viewed by traditional building authorities as a product that can be buried. When all was said and done we decided on the blue brand.
Generally perimeter drains are constructed using a product called Big O. This is a black, perforated, flexible pipe that is laid in a slightly sloped drainage ditch around the building. The pipe is accompanied by filter cloth and drainage rock and then buried. The idea is that if water accumulates around and in the ground surrounding the house, it will drain into the pipe and be passed around and beyond the house. However, our family and friends had had issues with Big O collapsing over time so we decided to use perforated 4″ PVC. We also decided to install three vertical cleanouts should we ever get a plug up. For us, digging through 10 feet of bermed earth is a bigger issue than with a traditional home! More pictures of the finished drain in a few days!
The PVC pipe was a lesson in going to the specialists. We priced this product at all the big box hardware stores and there was up to a $5 difference in a 10′ piece (ranging from $20 locally to $15 at Rona Hardware). As we were driving past Andrew Sheret, I pulled in and Chris came back with a quote of $11.10 per piece. With savings in hand, we started loading up.
Today another volunteer earthship builder arrived. James is from Newfoundland but is moving to Victoria and decided that before he got a job there, he wanted to do a few things, inlcuding help us for a few days. We are glad to have his help and look forward to Friday when Sean and Anna return with their “mate” Josh.
The photos are fairly straight forward but I’m having trouble manipulating them and being able to put captions on them. The trailer shot is of 30 of our 140 pieces of rigid insulation. There are several shots of the drainage ditch and because I’m always behind the camera, Katie took some pictures of me, doing what I do best, apparently: sitting and supervising!