Finishing The Insulation Layer

So it’s been 18 days since my last post on March 1st. I had worked in the oven on the 2nd and 3rd and then our car broke down. The transmission went out, so over the last two weeks I’ve been working on that. This is the first opportunity that I have had add this post. OK so on with the post.

So in the last post I started on the insulation layer. On the 2nd I was able to mix and apply 6 batches. I learned to mix a batch and empty it into the kiddie pool then get the next batch mixing while I apply the batch in the kiddie pool. This worked really well since the cob batches come out better the longer they run in the mixer.

So you can see in the picture that I got the first half of the insulation layer applied. I then cut some wire fencing into strips and wrapped them around the dome. I started to connect the strips together with wire and I ran out. So I used some zip ties I had to finish off the rest of the strips. I wasn’t too worried about using the zip ties for two reasons. Firstly the insulation layer should protect them from getting too hot and secondly their only purpose was to hold the fencing strips in place and shape until the rest of the insulation layer sets.
OK so why did I add the fencing strips? Well I added them to give a reinforcement to the insulation layer to avoid any checking or cracking do to the heat expansion of the thermal layer. I left straw sticking out and kept the insulation layer very rough to provide a good bonding surface for the second half of the insulation layer.

 So here is other half of the thermal layer. The one thing that I had to do was to add some extra sand and clay and thin out the mix. I wanted the outer half of the insulation layer to be able to be pushed and worked into and through the fence strips so the insulation layer would get a good bond and be nice and solid. At this point I think I’ve completely exceeded any and all earthquake standards from California.

You’ll notice that I left a gap on the bottom of the outer insulation layer. I did that on purpose. Since I’m going to add the adobe bricks around the base I wanted to have space to work at the top. When the bricks are added I’ll go and back fill that gap before the outer layer is put on.

So hopefully over the next week I can get to making the bricks to wrap the base in so I can repair the rain damage. I ‘ll take pictures for the next post.