Backfilling around the root cellar

I worked on the interior walls earlier in the week, getting three of them coated with the surface bonding cement – all but the long wall on the house side. So, yesterday, I began the process of backfilling against the walls of the cellar. It was nice to have the backhoe to use; it would’ve been overwhelming to do this job with a shovel.

I situated the backhoe behind the house near the corner of the root cellar and began moving dirt from the pile on the hill. This went fairly well. I could reach about 16 or so across the back edge. There was one problem: a few jerks with the hoe caused the bucket to slide over against one house post. I didn’t like that, of course. Initially, it wasn’t clear to me how to get it away from the house. I couldn’t back up because one rear tire was on the edge of the hole. I was able to move it without causing any damage to the house.

I was able to position the backhoe at a few different locations on either end of the cellar and put fill dirt in around almost all of the walls. I took it easy, knowing I didn’t want to knock into and mess up the walls.

On the house side of the cellar, there was about 14 feet of wall which the backhoe couldn’t reach because of the house frame. I had to use a shovel. Thankfully, the area to be filled here wasn’t to wide and didn’t need to be filled to the top of the blocks.

Here are a few photos taken after I finished today (the pvc on either end is for air vents):

Root cellar: surface bonding cement

We’ve had more than five inches of rain during the last nine days. In between some of the showers and storm, I’ve been able to work some on the root cellar. The frequent rain has been frustrating in that it’s kept me from getting things done like I want to, but that’s the way it goes.

The blocks are all stacked for the walls. I was able to fill 12 cores in the walls last week when we had a mostly rain-free day. I filled six more cores yesterday, all that will be filled. Last Thursday I was able to apply the surface bonding cement to the outside wall toward the hill on the back of the root cellar. That night we received some very heavy rain (over an inch and a half of it) which caused some mud to break free on the back wall of the excavation. Not too much, but I was glad to have the wall done on that side.

Today, I installed the PVC through the end walls to which I will connect the fresh-air vents for the cellar. I used concrete and mortar to fix them in the wall and cover the holes around the edges.

Then, I finished parging the rest of the outside walls. It was muddy down in the hole around the outside of the cellar walls. The dirt is mostly clay and sticks to my boots like crazy. I wore my muck boots since they can be cleaned off fairly easily.

After finishing the outside walls, I changed shoes and began on the inside. I was able to parge one inside wall, an end one. I hope to finish the other three walls tomorrow.

I mixed the surface bonding cement in a wheel barrow today, using a garden hoe. It worked fairly well. Previously, I mixed it half a bag at a time in a five-gallon bucket using a paddle mixer with an electric drill. That method actually worked better, but my mixer needs repaired. So, I didn’t use it today.

The key is getting the right amount of water in the mix. If it’s too wet, it’ll slump off of the wall. If it’s too dry, it takes a lot more effort to trowel it on the wall. When it’s mixed just right, it trowels on smoothly and stays where it’s supposed to. It’s been a trial-and-error process getting the mix figured out.

Surface bonded concrete block walls look nice, I think. Better than regular, mortared block walls. It’ll be nice to see them all complete. At that point, I’ll start backfilling.  

The roof revisited, ventilation, and air conditioning

Here it is almost five months since the frame raising and I still don't have the roof on the house. I wanted it on a long time before now. It just hasn't come together. The ceiling took a fair bit of work. If this project wasn't being done debt-free, then things would probably be done more quickly. As it is, I must invest a lot of labor in order to save money. That just takes time.

I talked with a friend of mine who is, among other things, an insulation specialist and consultant about my plans for insulating my roof. He's the same guy who is going to spray the ceramic coating
on my metal later. With his input, I decided to go with a 10" space for the insulation. He'll come down from where he lives in Indiana and dense pack cellulose insulation in the space sometime this spring or summer. It'll provide about an R-40 insulation value, plus it will effectively create an air-tight roof. There is much to be gained by air-tightness.

Once the bale walls are plastered, the rest of the home will be very close to air tight. This will be great for heating and cooling. However, careful consideration needs to be given to ventilation of the indoor space. With an air tight home, moisture and pollutants within the home can create problems; there needs to be some sort of ventilation plan. I will have lots of windows, and they will provide ventilation. But what about the times when I don't want the windows open? As I've contemplated the situation, I have had as one of my desires to design and install a system that can basically work without dependence upon outside power and limited input from me. Tough design criteria.

The main part of the plan I've developed so far involves a cupola in the center of the home at the peak of the roof (I guess a cupola pretty much goes at the peak). I have the parts of it ready to be installed. If the weather is good, I'll hopefully install it within the week. It will be approximately 4 feet by 4 feet. There will be windows on each side -- a 2'x3' on the front, a 2'x2' on the back, and a 2'x18" on each of the sides. The front and back windows will be rigged so that I can open and close them from inside the house below the cupola (since it would require a ladder to get into the cupola space). These windows in the cupola will provide ventilation using the natural chimney/convection effect the cupola will provide. Initially, the windows in the house will provide the air intake while the cupola works to exhaust air, controlled by how far the windows are opened.

Another aspect of the system which I will add at a later time is natural cooling for the house. This system will utilize the cupola and the stack effect it will create. Incoming air will be controlled through duct work that is connected to underground tubes through which the outside air will flow before entering the house. These tubes (nine 4" sewer pipes each with a run of 50'-75') will be buried about 4' in the ground where the temperature remains fairly constant (about 60 degrees). I'll see about drawing a diagram of this later. Because of the insulation value and tightness of the home, I expect that the constant flow of conditioned air introduced into the house through these tubes will not need to be that great. So, the system will help condition the air in the house at a comfortable level without any electricity needed. In the winter, the same system can be used to introduce air for ventilation that has been warmed by the earth.

The natural air conditioning aspect is still be developed in my head. The cupola, though, is nearly a reality. After I have it installed (without the windows), I'll get the roof put on. I have some friends who are going to help me with that soon.