Long Earth Tubes

Posted on September 6, 2014 by Simon

While the trench was open, it was our chance to lay the drain tile and earth tubes. We didn’t set the timelapse and we were too busy working to take many photos, but it is an important step for any earth sheltered home, so I want to capture a few details. Sorry, no timelapse.

We had already laid the drain tile and earth tube close to the house as we back-filled that portion. Click here for that story. But we still needed to run long tubes from the house to daylight.

The bottom of the trench was already sloped to 1% and the septic line, made of 4″ schedule 40 PVC, was already in place (done by the excavator and already approved by the plumbing inspector). We needed to bury it, but with a constant slope. Sherri and I used shovels and rakes to pull down dirt and bury the original line by about 6 inches. We (and the boys) stomped on this layer to pack it down, especially next to the buried septic pipe. The end result was a nicely sloped flat bottom trench.

We connected 100 ft long segments of 6″ corrugated drain pipe to the ends of the pipe we had already buried up by the house. We used a proper fitting connector piece and also taped it heavily and covered the connection in landscapers fabric. We laid these two parallel drain tiles along the trench and periodically placed dirt on them to even everything out and keep them separated by a couple feet. I would have liked to have separated them by more, and I did where the trench was wide enough. In all, we added about 150 ft of pipe to each end of the drain tile loop.

Normally, a drain tile loop is connected to a single long pipe that runs to daylight. However, by connecting each end to its own pipe, I am able to use it as an earth tube circuit with an inlet and outlet or two inlets. The other end of the pipes goes into the house, but I can simply connect those ends together if I want the air to circulate under the mass of the house without entering it (by-passive annual solar heating). The extra cost is the additional 150 ft of pipe, which cost me about ~$100.

The second layer of earth tubes was the 8 inch double wall (smooth inside) HDPE pipes. These come in straight 20ft segments that have a bit of flex to them. You can connect the pipes directly (bell and spigot ends with soil tight connectors) or you can connect them with 30 or 45 degree joints. It was a hot day and we did not have the energy to properly bury the 6″ corrugated drain tile before laying the larger earth tubes, so we decided to mount the larger earth tubes to the side of the slope (with stakes) a couple feet above the previous layer. This still left more than 10 ft of earth above these pipes for most of the distance and gave us more than 6 ft between the two parallel pipes.

At the end of the day, we had 4 earth tubes, each over 150 ft long, going from the house to “daylight” along the trench.

The next step would be backfilling.

Later, while back-filling the trench, we made sure that the 8 inch pipes stayed in place while the excavator back-filled below/between them and the 6″ pipes… This took some care and probably added at least an hour to the back filling process. The excavators charged by the hour, so that should probably be counted in the cost of the earth tubes, but seemed like a bargain compared to backfilling that trench manually on that hot day. I did pull out some of the stakes when they were no longer needed to hold the pipe still, but many were buried in place at an additional cost.

First Electrical Inspection

Posted on August 6, 2014 by Simon

This weeks focus was on preparing for Shotcrete… The basic studs and lath were up, but we needed to get all the rough electrical and rebar in place. Sherri and I had a lot of work to do.

Here is the video.

The electrical rough-in inspection must be done before the walls are closed up. Usually, that means before drywall, but for us, it means before shotcrete. In our township, electrical inspections are done only during a few specific hours each week, so we had to catch the two-hour Wednesday morning slot or Shotcrete would be delayed to the following week.

I has carefully designed the electrical layout weeks before, and then tweaked it based on Sherri’s input. Now, Sherri and I just needed to work as quickly as we could to place the boxes, run the conduit and then finally, pull the wires thru. We used Carlon ENT (smurf tube) and I had quite a hassle getting all the boxes that I needed. Next time, I will order in advance, but that is another story.

The process took longer than I expected, you can see I am working on it several days the week before. We still had work to do on this inspection day, so we came in very early and got going. We had not been finished long when the inspector arrived. He was very pleasant and actually said he appreciated that we were doing the electrical ourselves. That was a surprise because I expected that any inspector, especially one who was a professional electrician himself, would be somewhat against the idea of home owners taking on their own electrical. He made a few small suggestions for how to keep concrete out of the openings, and handed us our “approved” inspection paperwork.

Next, Sherri and I got going on Rebar. Mostly, I was cutting and Sherri was tying.

At the end of the day, my friend, Nate, arrived to check out the site. He had been up from Indiana for a conference in Ann Arbor. He reminded me that I had first told him about this idea at my dining room table nearly 6 years ago. I didn’t ask if he thought I was crazy, then or now ;^)

Our most expensive date ever!

Posted on June 25, 2014 by Simon

Contents

We closed on our construction loan!
Sourcing
Construction Birds
Eye Candy

This afternoon, my wife and I had our most expensive date ever!

We closed on our construction loan!

Getting this loan was a long and painful process that involved an appraiser, our insurance lady (that we ended up dumping because she was messing everything up) and a few other big surprises. I plan to document more at a later date, but here are the basics of what happened recently.

Last week, we had asked for an updated estimate of the closing costs. Of course, there were all the usual “fees”, including flood inspection, etc. The biggest of the recent surprises was that the bank wanted us to deposit all the money we planned to use, up front, in their account, so they could manage the disbursements and make sure it all goes into the construction. The difference with this latest update was that the bank added 10% more to cover “unexpected costs”. This was a significant jump that had not been included in previous discussions (they had been willing to accept that I had built safety factors into each line item). We scrambled to figure out how to scratch together the additional money (imagine suddenly needing to find 10% of the cost to build your home).

We could have swung it, but I was worried about our shrinking liquidity (I still need to buy tools, rent equipment, etc. and those costs are not covered by the construction loan). We ended up deciding to take some money out of our retirement savings plan. We will need to start paying it back to ourselves immediately (it starts coming out of my next pay check) or face a tax penalty, but the interest rate (to ourselves) was good and there were no significant fees. It was actually a pretty painless process and we put the paperwork together in about 20 minutes (Sherri and I working together). We took a bit more than we thought we needed, just in case. That check arrived yesterday.

Today started with Sherri still up from the night before going over the receipts that we have already paid. I gave up and went to bed at midnight, but I assume she checked everything more than twice more (as is her nature). These receipts are required to support our “Sworn Statement” that says how much we have paid and how much we have left to pay.

We showed up for our lunch time appointment at the bank today with a big accordion-folder worth of paperwork.

The first biggest surprise was that we were expected to pay off the remaining mortgage on our land before the new loan would commence. I had thought our land may come up since the appraisal was based on the house and land and I figured it may occur to the bank that they had already loaned us something, but I thought they would take the money out of what they were going to loan us now. Instead it was added up front as closing costs before the other loan would go through. Ouch. Good thing we had more in the account that we thought we needed. But this is a significant cut to our liquidity.

The silver lining is that we now own the land outright and no longer have that land payment. Also, the new mortgage percentage went down a bit from the last estimate, so in the end, our payment is very reasonable (over 30% lower than we thought it would be for the house and land payments combined).

We spent over an hour signing papers. Sherri is very thorough and likes to read everything; she found a number of mistakes, including her name spelled wrong several ways on a single page. The lady at the bank had to make a number of runs back upstairs to reprint documents with corrections. She was getting a bit tired by the end of it.

Eventually we got through it all and the Earth Sheltered Umbrella Home is fully funded.

Sourcing

I finally got the bill for the footings today. It was a volume plus materials sort of deal, so I was a bit nervous about how the cost of materials would add up. However, it did seem reasonable. I am not thrilled about all the unused forming supplies that I bought. I hope they don’t get wrecked by the weather before we can use them on the main floor footings (I have them covered with 6mil plastic at the moment). The cost of the concrete was 6% lower than expected and the giant pump truck was 14% lower than expected. Unfortunately, the rebar and other steel was 17% higher than expected, probably due to that 18% bump in the price of steel over the past year. Overall, we are still on budget.

I also purchased a new 26ft tall scaffold tower today. I had been trying to get a used one. There were not many to choose from and most looked like rusty pieces of junk. The worst part was they were priced only 30% below new. I found one nice aluminum one for a reasonable price, but I called the guy and he had sold it for scrap. In the end, I needed one next week, so I decided to pay a little more and get a brand new one, and that was for a “delux” model with the extra wide outriggers and other safety features. It should arrive the middle of next week along with my steel studs (which were originally supposed to arrive last Friday). I should be able to sell it at the end of construction for a reasonable price.

I had also been looking at buying turnbuckles to help me plumb the steel stud walls (tricky because I don’t have a top track to attach to). I was looking at the sort of thing that ICF installer’s use to straighten and plumb their walls before a pour. I found them to be very expensive, so I designed my own and priced it out. I figure I can make equivalent hardware for less than 1/10^th the price of buying them. The only catch is that I will need to buy that MIG welder sooner, but I planned to get it for the main floor steel anyway.

I have a 25% off coupon for a nice MIG welder (another thing I couldn’t find second hand), and will probably pick that up this weekend.