In the previous two segments, we put dirt over the shotcrete and then added our waterproof insulating umbrella. In this segment, we put an additional layer of dirt over our umbrella, then plant grass and work on the retaining walls.
For your viewing pleasure, here is the timelapse video…
As always, not everything makes it into the videos. One part that didn’t quite make it was adding the layer of blocks along the top edge of the wall above the back door. That wall is an ICF wall, basically 6 inches of reinforced concrete poured between two sides of insulation. We put a good amount of blue max waterproofing on the top edge and then I made sure that the billboard vinyls (17 mill reinforced) also overlapped the edge and I mortared 3 layers (about 12 inches) of block along the top edge to hold it all in place… I thought this would be good enough. However, water finds a way… It was able to get between the ICFs and the concrete and run down the inside of my wall all winter… I’ll need to tear those blocks off and put in some continuous metal flashing at some point.
When we started laying it out, I assumed that the experts would know what to do. Of course, they were pretty uncomfortable with my not having a detailed plan, but were nice enough to work with me. So, the first lesson learned was that I really should have come with a plan and not put that on the contractor. As it turned out, I really didn’t bring enough blocks to for that back wall. Some sort of math problem. So that was my second mistake. The compromise solution was to turn the blocks side ways and lean them back against the hill… I know this is not ideal and I already expect a lot of negative comments on Youtube. I decided the only way to overcome that was to put a lot of concrete and rebar behind the blocks to tie them together and form a continuous dam. This chewed up a bunch of time, but it is over a year (two winters and two springs) later and the wall is so solid that the mortar hasn’t even cracked.
Other tricks up my sleeve
Sherri was concerned that someone would fall off that boulder wall, in fact, she always calls it the “death wall”. She insisted that I put a rail along the top and bottom edge. I wanted that rail to be as slender as possible and decided I could use copper pipe for posts and rails. This isn’t against code if I don’t put a walking path within 6 ft of the rail. When used as the posts, the copper pipe would be much easier than a wooden post to attach to the boulders… Just drill it in. The problem is that it wasn’t really stiff enough. I found that “L type” copper pipe was quite a bit thicker and stronger, but I still wouldn’t want to rely on it. I also found that 1/2 inch L copper fits almost perfectly inside 3/4 inch L copper… This made it more than twice as stiff, especially if I filled the gap with epoxy… So that is what I did. The last problem was that the holes were not drilled perfectly vertical (that is harder to do than you might think), so you see they are a bit off plumb at the start, but later we were able to bend them vertical.
Here are some pics, mostly just old scenes since this wasn’t really a photogenic stage. Enjoy.
These boulders were used to keep the dirt on the roof from spilling around the front… You can also see the billboard vinyls, some carpet, etc.
Walking with the dog
Walking to pick up the camera…
When building a stone wall like this, you often need to spread the stones out as you search for the perfect one. That leads to this sort of messy chaos.
Michael being goofy for the camera before turning it off.
Sometimes we forget to turn off the camera at the end of the day and bring it back into the shop still on… I saw the little red light flash as this pic was taken. I included it so you could see how the shop looks.
The shop, on a clean day (not usually this clean) viewed from the front doors.
Cleaning up the north wall… On this day, I arrived just at sunset, so the first few pics are quite nice.
This guy had seen my stuff on line and also happened to work in Aerospace at one of my customers… He wanted to come check it out and volunteered to help me out to make up for the tour time… That worked for me. He brought his little brother also.
David likes to jump from the death wall… Climbing it is also fun. Hence Sherri likes to call it the death wall.
In the previous post, we added the first layer of dirt over the home. In this next step, we add the “umbrella” layer to keep the first layer of dirt dry and warm. The umbrella is made of layers of rigid insulation and billboard vinyls and topped with a pond liner and carpet. Of course, I’ll try to give you some details into the practical construction of this umbrella, but first, the timelapse video.
Not so easy
When I read John Hait’s book oh PAHS (Passive Anual Heat Storage) he talks about coming up with the umbrella idea because it made it easier to cover the dome in insulation. So I guess I thought it would be the easy part and didn’t really put as much pre-thought into the install as I have for other aspects of this home. However, I was very wrong. It was not easy and don’t let the video make you think it was.
The first challenge was getting the pieces to stay where you put them. This was hard enough on the flat spots and only got more and more challenging for the steeper slopes. I tried a number of things like using wood stakes (I used my table saw to cut a 2×4 into wood weges that were 1/4 inch thick and 6 inches long and pushed them into the sheet to give it traction). The stakes helped with the first layer, but I couldn’t use them on the second. Tape helped a little, but was often foiled by the tiniest amount of sand or moisture. I even tried sliding the insulation between layers of vinyl, but that was difficult to do precisely.
The second challenge was getting the shapes all cut just right. It was enough of a hassle to cut away for the skylights, etc. But dealing with trying to fit rigid rectangles to the compound curvature of a hillside as the sand shifted under your feet was incredibly frustrating.
Then we added the billboard vinyls, which wasn’t too bad. Gluing them with the HH-66 was also pretty straightforward. But once the vinyls were on, the insulation became more difficult to manage. If the underlying layer shifted, it was very difficult to get back exactly how you wanted it (butt jointed with no gaps). It also became much much harder to add the next layer of insulation. Even walking on it was difficult in the steep areas and we kept sliding off. Normally, I would have considered the slide as fun, but it wasted time and messed up the insulation again.
Getting the giant heavy pond liner up there (hardly shown in the video) was also a challenge and dragging it messed up the underlying vinyls and insulation. Pretty stressful actually.
Then the carpet layer helped… It was pretty good in terms of ease of install and its weight actually locked in the underlying layers pretty well while also making it easier to walk around. Most of it was in pretty decent shape and some of it was even brand new (trimming from an install?), but some of it was gross. I recall one had fingernails and other nastiness on it as if it had been stripped from a repossessed home where the evicted tenants were not big on cleaning (I assume people that disgusting were evicted ;).
In the end, I had a few regrets.
Primarily, I wished I had put a bit more insulation right up against the vertical sides of the building. It would have been easy to add it there and I wouldn’t have had to worry so much about it after the dirt was added and those steep sections were just so much harder to insulate.
I also wished I had dumpster dived for a couple more carpet loads. It was clear to us that carpet prevented erosion. We only had erosion in the spots that had no carpet. You could see that the erosion stopped in nice square shapes along the edges of the carpet layers. We ended up coming back and adding carpet to those spots, but it was much more work later then it would have been before adding the final dirt.
I am not yet sure if I will regret not putting more insulation. As I said, it is about running out of time and money. Did I insulate enough? Was it thick enough? Did it go out wide enough? Even John Hait says he didn’t think he went wide enough. I think I am OK there, but wonder if I will regret not spending a bit more on insulation at this stage.
The silt fence was a county requirement with a fine of several thousand dollars if it wasn’t installed after excavation. The regulations include that it should be installed correctly, which requires a trench first so the bottom of the fence can be buried to actually catch any silt that runs off the site. To do this, there is really nothing better than a little tractor with a plow. I highly recommend it to save hours of annoying digging.
One other pro-tip is to screw a piece of scrap wood as a furring strip to the stapled side of each post. Those staples don’t last long and it is much easier to add a strip of wood now that will hold the fabric in place permanently. Or maybe you prefer to go back and fix the fence every few weeks.
A gallery of pics… A bit light for this section because no one was feeling like taking pics and it was also difficult to get any good angles on the umbrella anyway.
John chilling for a moment during the hard afternoon.
Sherri on the steepest and trickiest part of the slope.
The little plow from the tractor did a great job forming the trench for the silt fence. Thanks again to the Roe Brothers for loaning it to me.
David was a trooper helping me out that day.
Dumpster diving is fun 😉
Sherri Holding on tight to my belt as I leaned over to put in the screws on the underside of the ledge. It wasn’t something I asked for, but I appreciated the caring 😉
We put lath over the insulation so that a final layer of concrete (stucco) would stick to it.
Building up the layers on the little edge walls.
Sherri glued most of the joints.
We glued the vinyls together with HH-66 vinyl cement. It basically melts them together with a chemical bond.
Follow the instructions and the glued joint is stronger than the rest of the vinyl.
Doing some final gluing with the HH-66
Michael posing for the camera. In the back ground you can see the sand bags we used as weights. Also, the skylight curb got an extra layer to shed water, but its not shown in the video. You will see it in the videos for the final dirt layer.
When you buy a pond liner, they give you a big square. If your pond is round, you cut off the corners. The Roe Brothers (the excavator crew) had kept some pond liner corners from previous jobs they had done and gave some to me. None were large enough to completely cover the roof, but they certainly helped as a bonus layer. The pond liners were definitely more slippery than the vinyls were though.
Keep in mind that the dormers stick out from the actual building underneath, so this is probably covered well enough…
This shot gives you an idea of why it is called an umbrella…
We also built this wall to keep the next layer of dirt off the windows. I think I’ll make that the next video.
David helping me place that last load of carpet.
David messing around for the camera. He lives too close to Detroit.
Our earth-sheltered house design uses an “umbrella” concept to retain the heat and keep things dry. This post covers the first phase, the dirt under the umbrella. Still, it was a big step.
Often the story is best told with pictures anyway…
This is actually an action shot with the dozer pushing dirt over that edge
Here is the section of wall that fell out. I forgot I had this pic when I did the previous video. I guess I’ll go add it to that section of the blog.
In this scene, Dick couldn’t see where he was dumping so Steve was his eyes… Communication is key.
The shovels were left there to keep the insulation pushed against the wall until the spray glue dried…
Do you think he noticed the bulldozer or is it still a mystery how the line was cut?
I thought the repair was pretty interesting.
A shovel to remind Marty the depth and location of the power lines.
We had layers of insulation behind the boulders, but there was also insulation up against the playroom, etc. We used a lot of insulation.
Michael setting up the camera.
Dick Roe, an original Roe Brother. He seems to operate the excavator like it was an extension of his body. He has clearly spent enough hours in there that it is all muscle memory at this point.
I don’t recall why I was laughing…
Sherri surveying the destruction
At the end of the first day…
They switched fromt he small bucket to the big (wide) bucket, depending on what work they were doing. Like changing the bit in your screw driver.
Lifting the first vertical stone…
Sliding in the key stone
Steve and I put a lot of thought into the placement of each rock so they would interlock nicely. It is hard to see from these pics, but the vertical ones are tilted back and tucked behind the flat ones. They are also tucked behind the concrete wall. I later came back and used mortar betwen all the rocks and drilled and pegged them together with #5 rebar, etc. It has been about a year and I don’t see any cracks in any of the mortar yet.
The excavator is sitting on a ramp made by the bulldozer so it could reach high enough to place the dirt.
This is the view out our playroom window.
Steve (working for Roe Brothers as the man on the ground) was very helpful and fun to be around.
Shovels are for fine tuning the dirt placement
We had them dump dirt in thru the skylights so we wouldn’t have to take it in with wheelbarrows. We needed it for making stucco and to bring the floor height up from the footing depth to 6 inches below final floor depth.
Color is funny in this pic, but this is the dirt spilling out from between the dormers on the south side. Like sand thru an hour glass.
Pushing dirt up the north side of the bedrooms
After the dozer tore up the ground, I went and did some rock picking
How it all looks from half way down the hill
The insulation was placed and waiting to get to work on the umbrella.
End of day two.
End of the 2nd day and the guys are packing up to leave
The center section of the house still has no roof
This hill is pretty steep here, but hopefully will be improved with the other two layers
Just a look at the terrain at the end of the day
Michael at the end going to pick up the camera after the last scene.